SPM Chemistry Form 5 Chapter 3 Carbon Compound.ppt
ThivyahAhilan1
301 views
135 slides
Jul 23, 2024
Slide 1 of 135
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
About This Presentation
Chemistry form 5 chapter 3
Slide Content
Chapter 2:
Carbon
Compound
Carbon
Compound
Definitionof
Carbon
Compound
Compounds that containcarbon as
their constituent element
Carbon
compound
Inorganic
compounds
Organic
compounds
Compounds originating from
living things that contain the
carbon element bonded
covalently with other
elements such as hydrogen,
nitrogen, sulphur, and
phosphorus
Compounds originating from
non-living materials such as
oxides of carbon, carbonate
compounds and cyanide
compounds
2.1 TYPES OF CARBON COMPOUNDS
Carbon
Compound
Compounds that containcarbon as
their constituent element
Carbon
compound
Inorganic
compounds
Organic
compounds
Compounds originating from
living things that contain the
carbon element bonded
covalently with other
elements such as hydrogen,
nitrogen, sulphur, and
phosphorus
Compounds originating from
non-living materials such as
oxides of carbon, carbonate
compounds and cyanide
compounds
2.1 TYPES OF CARBON COMPOUNDS
Example
Petrol
Natural
Gas
Example
Protein
(C,H,N,O)
Fat
(C,H,O)
Alkohol
(C,H,O)
Starch
(C,H,O)
Organic compounds
containing only
hydrogen and carbon
Organic compounds containing
carbon and hydrogen and other
elements, such as oxygen, nitrogen,
phosphorus or halogens.
Petrol
Natural
Gas
Example
Protein
(C,H,N,O)
Fat
(C,H,O)
Alkohol
(C,H,O)
Starch
(C,H,O)
Organic compounds
containing only
hydrogen and carbon
Organic compounds containing
carbon and hydrogen and other
elements, such as oxygen, nitrogen,
phosphorus or halogens.
Hydrocarbons containing only single
bonds between carbon atoms
Example
Hydrocarbons containing at least
one double bond or triple bond
between carbon atoms.
Example
H H H
H –C –C –C –H
H H H
H H H
H –C –C = C –H
H Single bonds between
carbon atoms
bonds between carbon atoms
Example
Hydrocarbons containing at least
one double bond or triple bond
between carbon atoms.
Example
H H H
H –C –C –C –H
H H H
H H H
H –C –C = C –H
H Single bonds between
carbon atoms
Petroleum or crude oil
The fractions of hydrocarbons in
petroleum are separated at
different temperatures according
to the size of the hydrocarbons.
Long chain hydrocarbons are
cracked into smaller molecules at
a high temperature using a
catalyst.
The fractions of hydrocarbons in
petroleum are separated at
different temperatures according
to the size of the hydrocarbons.
Long chain hydrocarbons are
cracked into smaller molecules at
a high temperature using a
catalyst.
Big Molecules
-High boiling point
-Dark colour
-Low combustibility
-More viscous
C
20-C
70
C
20–C
50
C
10–C
16
C
14–C
20
C
1–C
4
C
5–C
9
Raw materials for petrochemical industry
Fuel for motor vehicles
C
5–C
10
Cooking gas
Fuel for aircrafts
Fuel for heavy vehicles such as buses
and lorries
Lubricating oil and candles
Fuel for ships and power stations
Road pavements
-High boiling point
-Dark colour
-Low combustibility
-More viscous
C
20-C
70
C
20–C
50
C
10–C
16
C
14–C
20
C
1–C
4
C
5–C
9
Raw materials for petrochemical industry
Fuel for motor vehicles
C
5–C
10
Cooking gas
Fuel for aircrafts
Fuel for heavy vehicles such as buses
and lorries
Lubricating oil and candles
Fuel for ships and power stations
Road pavements
Process of breaking long chain hydrocarbons
into smaller hydrocarbons
produces
Smaller hydrocarbon such as petrol that is used as fuel
Alkane and alkene with shorter chains to be used as raw materials in the
manufacturing of polymer, medicines, detergents, solvents, fertilizers
and many more useful products
catalyst such as mixture of
aluminiumoxide, Al
2O
3dan
silicon(IV) oxide, SiO
2
Heated at high
temperature
and pressure
into smaller hydrocarbons
produces
Smaller hydrocarbon such as petrol that is used as fuel
Alkane and alkene with shorter chains to be used as raw materials in the
manufacturing of polymer, medicines, detergents, solvents, fertilizers
and many more useful products
catalyst such as mixture of
aluminiumoxide, Al
2O
3dan
silicon(IV) oxide, SiO
2
Heated at high
temperature
and pressure
Examples of
cracking reaction
on long-chain
hydrocarbons into
smaller
hydrocarbon
molecules and
hydrogen gas
cracking reaction
on long-chain
hydrocarbons into
smaller
hydrocarbon
molecules and
hydrogen gas
Aim:To study the fractional distillation of petroleum
Materials:Petroleum and cotton
Apparatus: Filter paper, retort stand, thermometer (0°C−360°C), round bottom flask,
conical flask, test tube, Liebig condenser,
wire gauze, tripod stand, test tubes,
evaporating dish, porcelain chips,
wooden block and Bunsen burner.
EXPERIMENT : FractionalDistillation of Petroleum
Materials:Petroleum and cotton
Apparatus: Filter paper, retort stand, thermometer (0°C−360°C), round bottom flask,
conical flask, test tube, Liebig condenser,
wire gauze, tripod stand, test tubes,
evaporating dish, porcelain chips,
wooden block and Bunsen burner.
EXPERIMENT : FractionalDistillation of Petroleum
Procedure:
1. Measure 50 cm3 of petroleum and pour into a round bottom flask.
2. Add one spatula of porcelain chips into the round bottom flask.
3. Set up the apparatus as shown in Figure.
4. Gently heat the petroleum and collect four fractions of petroleum into four separate
test tubes at a temperature range of 30 °C − 80 °C, 80 °C − 120 °C, 120 °C − 160 °C
and 160 °C − 200 °C.
5. Observe each fraction of petroleum collected at different temperatures and record
the colour and their viscosity.
6. Place some cotton into an evaporating dish.
7. Put a few drops of the petroleum fraction collected in the test tube onto the cotton
in the evaporating dish.
8. Ignite the cotton and observe the colour of the flame and the quantity of soot by
placing filter paper above the flame.
9. Repeat steps 6 to 8 for petroleum fractions collected in test tubes 2, 3 and 4.
10. Record your observations in the table below.
EXPERIMENT : FractionalDistillation of Petroleum
1. Measure 50 cm3 of petroleum and pour into a round bottom flask.
2. Add one spatula of porcelain chips into the round bottom flask.
3. Set up the apparatus as shown in Figure.
4. Gently heat the petroleum and collect four fractions of petroleum into four separate
test tubes at a temperature range of 30 °C − 80 °C, 80 °C − 120 °C, 120 °C − 160 °C
and 160 °C − 200 °C.
5. Observe each fraction of petroleum collected at different temperatures and record
the colour and their viscosity.
6. Place some cotton into an evaporating dish.
7. Put a few drops of the petroleum fraction collected in the test tube onto the cotton
in the evaporating dish.
8. Ignite the cotton and observe the colour of the flame and the quantity of soot by
placing filter paper above the flame.
9. Repeat steps 6 to 8 for petroleum fractions collected in test tubes 2, 3 and 4.
10. Record your observations in the table below.
EXPERIMENT : FractionalDistillation of Petroleum
Results:
Test tubeBoiling
Point / °C
Colour Viscosity Sootiness
1 30-80
2 80-120
3 120-160
4 160-200
EXPERIMENT : FractionalDistillation of Petroleum
Test tubeBoiling
Point / °C
Colour Viscosity Sootiness
1 30-80
2 80-120
3 120-160
4 160-200
EXPERIMENT : FractionalDistillation of Petroleum
Discussion
1. Why are porcelain chips added into the round bottom flask?
Answer:-
Some porcelain chips are used for uniform heating of petroleum and to avoid bumping
of the liquid due to uneven heating.
2. Why is a normal thermometer not used in this activity?
Answer:-
The boiling points of petroleum fractions are in the range of 30̊C -200̊C. The maximum
temperature that a normal thermometer can record is 110̊C. Thus petroleum fractions
which have a boiling point exceeding 110̊C can not be separated.
1. Why are porcelain chips added into the round bottom flask?
Answer:-
Some porcelain chips are used for uniform heating of petroleum and to avoid bumping
of the liquid due to uneven heating.
2. Why is a normal thermometer not used in this activity?
Answer:-
The boiling points of petroleum fractions are in the range of 30̊C -200̊C. The maximum
temperature that a normal thermometer can record is 110̊C. Thus petroleum fractions
which have a boiling point exceeding 110̊C can not be separated.
Discussion
3. State the relation between the boiling point of the fraction of petroleum and the
following:
(a) its colour,
(b) its viscosity, and
(c) quantity of soot formed after burning.
Answer:-
a) The higher the boiling point, the darker the colorof the fractions
b) The higher the boiling point, the higher the viscosity of the fractions
c) The higher the boiling point, the higher the quantity of soot formed after combustion
4. Which fraction of petroleum is most flammable?
Answer:-
Fraction 1
3. State the relation between the boiling point of the fraction of petroleum and the
following:
(a) its colour,
(b) its viscosity, and
(c) quantity of soot formed after burning.
Answer:-
a) The higher the boiling point, the darker the colorof the fractions
b) The higher the boiling point, the higher the viscosity of the fractions
c) The higher the boiling point, the higher the quantity of soot formed after combustion
4. Which fraction of petroleum is most flammable?
Answer:-
Fraction 1
Alternative energy sources
other than nonrenewable
fossil fuels
Biodiesel Bioethanol
Biogas
Biomass
Organic matter of plants and
animals. It contains latent
energy derived from the sun.
other than nonrenewable
fossil fuels
Biodiesel Bioethanol
Biogas
Biomass
Organic matter of plants and
animals. It contains latent
energy derived from the sun.
2.2 HOMOLOGOUS SERIES
What is
Homologous
Series???
What is
Homologous
Series???
The same general formula
The same functional group
The same chemical properties
Consecutive members differ by one carbon atom and two
hydrogen atoms (CH
2 or RMM=14)
Physical properties that gradually change from one member
to the next
Examples
Alkane
Alkene
Alkyne
Alcohol
Carboxylic
Acid
Ester
The same functional group
The same chemical properties
Consecutive members differ by one carbon atom and two
hydrogen atoms (CH
2 or RMM=14)
Physical properties that gradually change from one member
to the next
Examples
Alkane
Alkene
Alkyne
Alcohol
Carboxylic
Acid
Ester
HOMOLOGOUS SERIES
Homologous
series
General Formula Functional group Name of functional
group
Type of organic
compound
Alkane C
nH
2n+2,n=1,2,3,... Single bond between
carbon atoms
Saturated
hydrocarbon
Alkene C
nH
2n , n=2,3,...... Double bond between
carbon atoms
Unsaturated
hydrocarbon
Alkyne C
nH
2n-2,n=2,3,...... Triple bond between
carbon atoms
Unsaturated
hydrocarbon
Alcohol C
nH
2n+1OH, n = 1, 2, ... Hydroxyl Non hydrocarbon
Carboxylic
Acid
C
nH
2n+1COOH,
n = 0, 1, 2..
Carboxyl Non hydrocarbon
Ester C
mH
2m+1COOC
nH
2n+1
n = 0,1, 2, ...n = 1,2,3...
Carboxylate Non hydrocarbon
Homologous
series
General Formula Functional group Name of functional
group
Type of organic
compound
Alkane C
nH
2n+2,n=1,2,3,... Single bond between
carbon atoms
Saturated
hydrocarbon
Alkene C
nH
2n , n=2,3,...... Double bond between
carbon atoms
Unsaturated
hydrocarbon
Alkyne C
nH
2n-2,n=2,3,...... Triple bond between
carbon atoms
Unsaturated
hydrocarbon
Alcohol C
nH
2n+1OH, n = 1, 2, ... Hydroxyl Non hydrocarbon
Carboxylic
Acid
C
nH
2n+1COOH,
n = 0, 1, 2..
Carboxyl Non hydrocarbon
Ester C
mH
2m+1COOC
nH
2n+1
n = 0,1, 2, ...n = 1,2,3...
Carboxylate Non hydrocarbon
Molecular formula, Structural formula and the
Nomenclature of Homologous Series members
Molecular formula is a chemical formula that
show the type and actual number of atoms of
each element in a molecule
Structural formula shows the type of bond and
how the atoms in a molecule are bonded to each
other
CH
4
Represent one pair
of electrons shared
to form a single
covalent bond
Molecular
formula
Electron
arrangement
Structural
Formula
Nomenclature of Homologous Series members
Molecular formula is a chemical formula that
show the type and actual number of atoms of
each element in a molecule
Structural formula shows the type of bond and
how the atoms in a molecule are bonded to each
other
CH
4
Represent one pair
of electrons shared
to form a single
covalent bond
Molecular
formula
Electron
arrangement
Structural
Formula
Root Name
Represents the
number of carbon
atoms in the
longest chain
Suffix
Represents the
homologous series
Number
of C
1 2 3 4 5 6 7 8 9 10
Root
name
MethEthPropButPentHexHeptOctNonDec
Homologous
series
AlkaneAlkeneAlkyneAlcoholCarboxylic
Asid
Ester
Suffix “ane”“ene”“yne” “ol” “oic” “oate”
Represents the
number of carbon
atoms in the
longest chain
Suffix
Represents the
homologous series
Number
of C
1 2 3 4 5 6 7 8 9 10
Root
name
MethEthPropButPentHexHeptOctNonDec
Homologous
series
AlkaneAlkeneAlkyneAlcoholCarboxylic
Asid
Ester
Suffix “ane”“ene”“yne” “ol” “oic” “oate”
Write the molecular formula and the name of an alkane with three
carbon atoms.
When n = 3
Molecular formula of C
nH
2n + 2= C
3H
2(3) + 2= C
3H
8
Root name : Prop Suffix : -ane
The name of alkane with three carbon atoms is propane
Write the molecular formula and the name of an alkene with five carbon
atoms.
When n = 5
Molecular formula of C
nH
2n = C
5H
2(5) = C
5H
10
Root name : Pent Suffix : -ene
The name of alkane with three carbon atoms is pentene
carbon atoms.
When n = 3
Molecular formula of C
nH
2n + 2= C
3H
2(3) + 2= C
3H
8
Root name : Prop Suffix : -ane
The name of alkane with three carbon atoms is propane
Write the molecular formula and the name of an alkene with five carbon
atoms.
When n = 5
Molecular formula of C
nH
2n = C
5H
2(5) = C
5H
10
Root name : Pent Suffix : -ene
The name of alkane with three carbon atoms is pentene
Alkane
Structural Formula
CH4
Model of
CH4 molecule
First member, n = 1
Molecular Formula: C
1H
2(1)+2= CH
4
Name of members: Methane
Cooking Waxy layer
Saturated Hydrocarbon
-The presence of a single covalent bond
between carbon atoms.
Functional Group
-A single covalent bond between carbon
atoms,
General Formula
-C
nH
2n+2,n=1,2,3,...
Structural Formula
CH4
Model of
CH4 molecule
First member, n = 1
Molecular Formula: C
1H
2(1)+2= CH
4
Name of members: Methane
Cooking Waxy layer
Saturated Hydrocarbon
-The presence of a single covalent bond
between carbon atoms.
Functional Group
-A single covalent bond between carbon
atoms,
General Formula
-C
nH
2n+2,n=1,2,3,...
Alkene
Structural Formula
C2H4
Model of
C2H4 molecule
Unsaturated Hydrocarbon
-The presence of a double covalent bonds
between carbon atoms.
Functional Group
-Double bond between carbon atoms,
General Formula
-C
nH
2n, n = 2,3...
Ripening bananas
First member, n = 2
Molecular Formula: C
2H
2(2)= C
2H
4
Root Name: Obtained from the longest
carbon chain.
Add the suffix "ene”to the root name
because "ene”is a member of the alkene
homologous series .
Name of member : Ethene
Structural Formula
C2H4
Model of
C2H4 molecule
Unsaturated Hydrocarbon
-The presence of a double covalent bonds
between carbon atoms.
Functional Group
-Double bond between carbon atoms,
General Formula
-C
nH
2n, n = 2,3...
Ripening bananas
First member, n = 2
Molecular Formula: C
2H
2(2)= C
2H
4
Root Name: Obtained from the longest
carbon chain.
Add the suffix "ene”to the root name
because "ene”is a member of the alkene
homologous series .
Name of member : Ethene
Alkyne
Structural Formula
C2H2
Model of
C2H2 molecule
Unsaturated Hydrocarbon
-The presence of a triple covalent bonds
between carbon atoms.
Functional Group
-Triple bond between carbon atoms,
General Formula
-C
nH
2n-2, n = 2,3...
METAL CUTTING
Root Name: Obtained from the longest
carbon chain.
Add the suffix “yne”to the root name
because “yne”is a member of the
alkyne homologous series
Name of member : Ethyne
First member, n = 2
Molecular Formula: C
2H
2(2)-2= C
2H
2
Structural Formula
C2H2
Model of
C2H2 molecule
Unsaturated Hydrocarbon
-The presence of a triple covalent bonds
between carbon atoms.
Functional Group
-Triple bond between carbon atoms,
General Formula
-C
nH
2n-2, n = 2,3...
METAL CUTTING
Root Name: Obtained from the longest
carbon chain.
Add the suffix “yne”to the root name
because “yne”is a member of the
alkyne homologous series
Name of member : Ethyne
First member, n = 2
Molecular Formula: C
2H
2(2)-2= C
2H
2
AlCOHOL
Structural Formula
C3H7OH
Model of
C3H7OH molecule
Non Hydrocarbon
-Containscarbon, hydrogen and oxygen
atoms.
Functional Group
-Hydroxyl group, OH
General Formula
-C
nH
2n+1, n = 1,2,3...
Antiseptic
First member, n = 3
Molecular Formula: C
3H
2(3)+1= C
3H
7OH
The hydroxyl group OH is different
from the hydroxide ion OH‒ in alkali.
There are no hydroxide ions OH‒ in
alcohol.
perfume solventfuel
Structural Formula
C3H7OH
Model of
C3H7OH molecule
Non Hydrocarbon
-Containscarbon, hydrogen and oxygen
atoms.
Functional Group
-Hydroxyl group, OH
General Formula
-C
nH
2n+1, n = 1,2,3...
Antiseptic
First member, n = 3
Molecular Formula: C
3H
2(3)+1= C
3H
7OH
The hydroxyl group OH is different
from the hydroxide ion OH‒ in alkali.
There are no hydroxide ions OH‒ in
alcohol.
perfume solventfuel
Naming of straight chain alcohols according to the IUPAC nomenclature:
(i) Determine the number of carbon atoms in the longest carbon chain containing hydroxyl group –OH
(ii) Replace the “e” ending from the alkanename with “ol”
Corresponding alkanename: Butane
Alcohol name: Butanol
Hydroxyl position is at the second carbon atom
Numbering starts from the carbon atom that
is nearest to the hydroxyl group at the end of
chain
H H H H
l l I I
H C C C C H
I I I l
H H OH H
1234
4321
AlCOHOL
(i) Determine the number of carbon atoms in the longest carbon chain containing hydroxyl group –OH
(ii) Replace the “e” ending from the alkanename with “ol”
Corresponding alkanename: Butane
Alcohol name: Butanol
Hydroxyl position is at the second carbon atom
Numbering starts from the carbon atom that
is nearest to the hydroxyl group at the end of
chain
H H H H
l l I I
H C C C C H
I I I l
H H OH H
1234
4321
AlCOHOL
2.2 HOMOLOGOUS SERIES
Carboxylic
acid
Structural Formula
HCOOH
Model of
HCOOH
molecule
Non Hydrocarbon
-Containscarbon, hydrogen and oxygen
atoms.
Functional Group
-Carboxyl group, COOH
General Formula
-C
nH
2n+1, n = 0,1,2,3...
Ant bites vinegar
First member, n = 0
Molecular Formula: C
0H
2(0)+1COOH = HCOOH
Name of member : MethanoicAcid
acid
Structural Formula
HCOOH
Model of
HCOOH
molecule
Non Hydrocarbon
-Containscarbon, hydrogen and oxygen
atoms.
Functional Group
-Carboxyl group, COOH
General Formula
-C
nH
2n+1, n = 0,1,2,3...
Ant bites vinegar
First member, n = 0
Molecular Formula: C
0H
2(0)+1COOH = HCOOH
Name of member : MethanoicAcid
Naming of carboxylic acid according to the IUPAC nomenclature:
(i) Determine the number of carbon atoms, and state the corresponding alkanename
(ii) Replace the “e” ending from the alkane name with “oicacid”
Molecular Formula: CH
3COOH
The number of carbon atoms: 2
The corresponding alkanename: ethane.
The name for CH
3COOH: ethanoicacid
Molecular Formula: CH
3CH
2COOH
The number of carbon atoms: 3
The corresponding alkanename: propane
The name for CH
3CH
2COOH: propanoicacid
Carboxylic
acid
(i) Determine the number of carbon atoms, and state the corresponding alkanename
(ii) Replace the “e” ending from the alkane name with “oicacid”
Molecular Formula: CH
3COOH
The number of carbon atoms: 2
The corresponding alkanename: ethane.
The name for CH
3COOH: ethanoicacid
Molecular Formula: CH
3CH
2COOH
The number of carbon atoms: 3
The corresponding alkanename: propane
The name for CH
3CH
2COOH: propanoicacid
Carboxylic
acid
Physical Properties of Compound in
Homologous Series
Members of the homologous series of alkanes, alkenes and alkynes consists of
neutral molecules
Homologous Series
Members of the homologous series of alkanes, alkenes and alkynes consists of
neutral molecules
Physical Properties of Alcohols and
Carboxylic Acids
Homologous
series
Alcohol Carboxylic Acid
Boiling point Low boiling point that increases with the
increasing number of carbon atoms per
molecule.
Low boiling point that increases with
the increasing number of carbon
atoms per molecule
Physical state at
room
temperature
The first eleven members of alcohol exist
as liquids.
The first nine members of carboxylic
acid exist as liquids
Solubility in
water
•Methanol, ethanol and propanol are
miscible in water in all proportions.
•As the molecular size increases, the
solubility decreases.
•Methanoicacid, ethanoic acid and
propanoic acid are very soluble in
water.
•As the molecular size increases,
the solubility decreases.
Carboxylic Acids
Homologous
series
Alcohol Carboxylic Acid
Boiling point Low boiling point that increases with the
increasing number of carbon atoms per
molecule.
Low boiling point that increases with
the increasing number of carbon
atoms per molecule
Physical state at
room
temperature
The first eleven members of alcohol exist
as liquids.
The first nine members of carboxylic
acid exist as liquids
Solubility in
water
•Methanol, ethanol and propanol are
miscible in water in all proportions.
•As the molecular size increases, the
solubility decreases.
•Methanoicacid, ethanoic acid and
propanoic acid are very soluble in
water.
•As the molecular size increases,
the solubility decreases.
Exercise
Answer:-
P: Carboxylic Acid; Butanol
Q: Alkene; Butene
R: Alcohol; Propanol
S: Alkane; Heptane
T: Alkyne; Pentyne
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
1.For all compounds in the table above:
(i) state their homologous series
(ii) write their IUPAC names.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Answer:-
P: Carboxylic Acid; Butanol
Q: Alkene; Butene
R: Alcohol; Propanol
S: Alkane; Heptane
T: Alkyne; Pentyne
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
1.For all compounds in the table above:
(i) state their homologous series
(ii) write their IUPAC names.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Exercise
Answer:-
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
1.For all compounds in the table above:
(iii) draw the structural formula.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Answer:-
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
1.For all compounds in the table above:
(iii) draw the structural formula.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Exercise
Answer:-
(b) (i) Substance that exists in the form of gas : Q
(b) (ii) Substances that exist in the form of liquid: P, R, S and T
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
(b) List all compounds that exist in the form of:
(i) gas at room temperature. (ii) liquid at room temperature.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Answer:-
(b) (i) Substance that exists in the form of gas : Q
(b) (ii) Substances that exist in the form of liquid: P, R, S and T
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
(b) List all compounds that exist in the form of:
(i) gas at room temperature. (ii) liquid at room temperature.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Exercise
Answer:-
-Boiling point S is higher than Q
-Molecular size S is larger Q
-The van der Waals forces between the molecules S is stronger than Q
-More energy is needed to overcome the attraction between the S molecules compared
to Q molecules
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
(c) Compare the boiling points of compounds Q and S. Explain your answer.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Answer:-
-Boiling point S is higher than Q
-Molecular size S is larger Q
-The van der Waals forces between the molecules S is stronger than Q
-More energy is needed to overcome the attraction between the S molecules compared
to Q molecules
P Q R S T
C
3H
7COOH C
4H
8 C
3H
7OH C
7H
16 C
5H
8
(c) Compare the boiling points of compounds Q and S. Explain your answer.
Table shows the molecular formula of organic compounds P, Q, R, S and T from different homologous series.
Cover
Alkanes burn completely in excess oxygen, O
2,
releasing carbon dioxide, CO
2and water, H
2O
Example complete combustion of
methane:
CH
4(g) + 2O
2(g) CO
2(g) + 2H
2O(l)
1
2
3
4
5
6 Alkanes undergo incomplete combustion
when there is not enough or limited supply of
O
2
Incomplete combustion of alkanes
produces carbon particles, C (soot),
carbon monoxide gas, CO (poisonous) and
water, H
2O
Example incomplete combustion of
methane:
2CH
4(g) + 3O
2(g) 2CO(g) + 4H
2O(l)
CH
4(g) + O
2(g) C(s) + 2H
2O
The combustion of alkanes release large
amounts of heat.
The combustion of alkanes with more
number of C atoms will produce more soot
2,
releasing carbon dioxide, CO
2and water, H
2O
Example complete combustion of
methane:
CH
4(g) + 2O
2(g) CO
2(g) + 2H
2O(l)
1
2
3
4
5
6 Alkanes undergo incomplete combustion
when there is not enough or limited supply of
O
2
Incomplete combustion of alkanes
produces carbon particles, C (soot),
carbon monoxide gas, CO (poisonous) and
water, H
2O
Example incomplete combustion of
methane:
2CH
4(g) + 3O
2(g) 2CO(g) + 4H
2O(l)
CH
4(g) + O
2(g) C(s) + 2H
2O
The combustion of alkanes release large
amounts of heat.
The combustion of alkanes with more
number of C atoms will produce more soot
Alkanes undergo substitution reaction with halogens such as chlorine,
Cl
2and bromine, Br
2under sunlight or ultraviolet (UV) rays
Substitution reaction occurs when each hydrogen atom, H in an alkane molecule is
substituted one by one with halogen atoms, until all the hydrogen atoms, H have
been substituted
Sunlight or UV rays are needed to break the covalent bonds in the
halogen molecules, such as chlorine, Cl
2to produce chlorine atoms, Cl
Cl
2and bromine, Br
2under sunlight or ultraviolet (UV) rays
Substitution reaction occurs when each hydrogen atom, H in an alkane molecule is
substituted one by one with halogen atoms, until all the hydrogen atoms, H have
been substituted
Sunlight or UV rays are needed to break the covalent bonds in the
halogen molecules, such as chlorine, Cl
2to produce chlorine atoms, Cl
Alkenes burn completely in excess oxygen, O
2,
releasing carbon dioxide, CO
2and water, H
2O
Example complete combustion of
ethene:
C
2H
4(g) + 3O
2(g) 2CO
2(g) + 2H
2O(l)
1
2
3
4
5
6 Alkenes undergo incomplete combustion
when there is not enough or limited supply of
O
2
Incomplete combustion of alkenes
produces carbon particles, C (soot),
carbon monoxide gas, CO (poisonous) and
water, H
2O
The combustion of alkenes produces a
flame with more soot compared to
their corresponding alkanes
This is because alkenes have a higher
percentage of carbon by mass
compared to alkanes
2,
releasing carbon dioxide, CO
2and water, H
2O
Example complete combustion of
ethene:
C
2H
4(g) + 3O
2(g) 2CO
2(g) + 2H
2O(l)
1
2
3
4
5
6 Alkenes undergo incomplete combustion
when there is not enough or limited supply of
O
2
Incomplete combustion of alkenes
produces carbon particles, C (soot),
carbon monoxide gas, CO (poisonous) and
water, H
2O
The combustion of alkenes produces a
flame with more soot compared to
their corresponding alkanes
This is because alkenes have a higher
percentage of carbon by mass
compared to alkanes
Addition reaction occurs when another atom is added to each
carbon atom, C at the double bond –C = C –to form a single
covalent bond –C –C –.
carbon atom, C at the double bond –C = C –to form a single
covalent bond –C –C –.
Five addition reactions that occur on alkenes:
1. Addition of hydrogen (Hydrogenation).
2. Addition of halogen (Halogenation).
3. Addition of halogen halide.
4. Addition of water (Hydration).
5. Oxidation with acidified potassium manganate(VII), KMnO
4
solution.
1. Addition of hydrogen (Hydrogenation).
2. Addition of halogen (Halogenation).
3. Addition of halogen halide.
4. Addition of water (Hydration).
5. Oxidation with acidified potassium manganate(VII), KMnO
4
solution.
1. Addition of Hydrogen (Hydrogenation)
•Alkenes react with hydrogen at a temperature of 180 °C in the presence of nickel
/platinum as a catalyst to produce the corresponding alkanes.
C
nH
2n+ H
2
Alkene Alkane
Example:
Ethene gas, C
2H
4reacts with hydrogen gas, H
2in the presence of nickel as a catalyst at 180 °C
to produce ethane gas, C
2H
6.
C
nH
2n+2
C
2H
6(g)C
2H
4(g) + H
2(g)
•Alkenes react with hydrogen at a temperature of 180 °C in the presence of nickel
/platinum as a catalyst to produce the corresponding alkanes.
C
nH
2n+ H
2
Alkene Alkane
Example:
Ethene gas, C
2H
4reacts with hydrogen gas, H
2in the presence of nickel as a catalyst at 180 °C
to produce ethane gas, C
2H
6.
C
nH
2n+2
C
2H
6(g)C
2H
4(g) + H
2(g)
2. Addition of Halogen (Halogenation)
•Alkenes react with halogens such as chlorine, Cl
2and bromine, Br
2at room
conditions. For example, when ethene gas, C
2H
4is bubbled through bromine
water, Br
2, the brown colour of bromine water, Br
2is decolourised.
C
2H
4(g) + Br
2(l) C
2H
4Br
2(l)
•Alkenes react with halogens such as chlorine, Cl
2and bromine, Br
2at room
conditions. For example, when ethene gas, C
2H
4is bubbled through bromine
water, Br
2, the brown colour of bromine water, Br
2is decolourised.
C
2H
4(g) + Br
2(l) C
2H
4Br
2(l)
3. Addition of Hydrogen Halide
•Alkenes react with hydrogen halides, such as hydrogen chloride, HCl or
hydrogen bromide, HBr at room temperature to form haloalkane.
•For example, when dry hydrogen bromide gas, HBr is passed through ethene
gas, C
2H
4, bromoethane is produced.
C
2H
4(g) + HBr(g) C
2H
5Br (l)
•Alkenes react with hydrogen halides, such as hydrogen chloride, HCl or
hydrogen bromide, HBr at room temperature to form haloalkane.
•For example, when dry hydrogen bromide gas, HBr is passed through ethene
gas, C
2H
4, bromoethane is produced.
C
2H
4(g) + HBr(g) C
2H
5Br (l)
4. Addition of Water (Hydration)
•Alkenes react with water (in the form of steam) at high temperature and pressure, in the
presence of phosphoric acid, H3PO4 as a catalyst to produce alcohol.
C
nH
2n+ H
2O
•Example:
Ethene gas, C
2H
4undergoes an addition reaction with steam at the temperature of
300 °C, pressure of 60 atmand catalysed by phosphoric acid, H
3PO
4to produce
ethanol, C
2H
5OH.
C
nH
2n+1OH
C
2H
5OH (l)C
2H
4(g) + H
2O(g)
•Alkenes react with water (in the form of steam) at high temperature and pressure, in the
presence of phosphoric acid, H3PO4 as a catalyst to produce alcohol.
C
nH
2n+ H
2O
•Example:
Ethene gas, C
2H
4undergoes an addition reaction with steam at the temperature of
300 °C, pressure of 60 atmand catalysed by phosphoric acid, H
3PO
4to produce
ethanol, C
2H
5OH.
C
nH
2n+1OH
C
2H
5OH (l)C
2H
4(g) + H
2O(g)
5. Oxidation
•Alkenes react with acidified potassium manganate(VII), KMnO
4solution.
•In this reaction, two hydroxyl groups OH are added to the double bond.
•Alkenes decolourise the purple colour of acidified potassium manganate(VII),
KMnO
4solution.
•For example:
C
2H
4(g) + H
2O(g) + [O] C
2H
4(OH)
2
KMnO
4/ H
+
•Alkenes react with acidified potassium manganate(VII), KMnO
4solution.
•In this reaction, two hydroxyl groups OH are added to the double bond.
•Alkenes decolourise the purple colour of acidified potassium manganate(VII),
KMnO
4solution.
•For example:
C
2H
4(g) + H
2O(g) + [O] C
2H
4(OH)
2
KMnO
4/ H
+
Small alkene molecules undergo
addition reaction with one another to
form long chain molecules
Alkene molecules link together to form a
long chain of molecules called polymer
while the smaller alkenes are the basic
units called monomer
The reaction of alkene monomers to
form polymers is called addition
polymerisation
Example:
Ethene, C
2H
4undergoes addition
polymerization at 200
o
Cand pressure
of 1200 atm to produce polythene
In general:
addition reaction with one another to
form long chain molecules
Alkene molecules link together to form a
long chain of molecules called polymer
while the smaller alkenes are the basic
units called monomer
The reaction of alkene monomers to
form polymers is called addition
polymerisation
Example:
Ethene, C
2H
4undergoes addition
polymerization at 200
o
Cand pressure
of 1200 atm to produce polythene
In general:
Comparison Between Alkanes and Alkenes
Alkane Alkene
Saturated Hydrocarbon Unsaturated Hydrocarbon
Single covalent bond C –C Double covalent bond C = C
Substitution reaction Addition reaction
Percentage of carbon by mass is
lower
Percentage of carbon by mass is
higher
Less sooty flames More sooty flames
Example: Hexane, C
6H
14 Example: Hexene, C
6H
12
Hydrocarbonscontaining only the carbon and hydrogen elements
Complete combustion produces carbon dioxide, CO2 and water, H2O
Same physical properties
Number of carbon atoms are the same
Alkane Alkene
Saturated Hydrocarbon Unsaturated Hydrocarbon
Single covalent bond C –C Double covalent bond C = C
Substitution reaction Addition reaction
Percentage of carbon by mass is
lower
Percentage of carbon by mass is
higher
Less sooty flames More sooty flames
Example: Hexane, C
6H
14 Example: Hexene, C
6H
12
Hydrocarbonscontaining only the carbon and hydrogen elements
Complete combustion produces carbon dioxide, CO2 and water, H2O
Same physical properties
Number of carbon atoms are the same
A.Sootiness of Flame
Aim:To compare hexane, C
6H
14and hexene, C
6H
12for sootiness of flames during
combustion.
Problem Statement: Do alkanes and alkenes burn with the same quantity of soot?
Hypothesis:Hexene, C
6H
12burns with a more sooty flame compared to hexane, C
6H
14.
Variables:-
(a)Manipulated Variable: Hexane, C
6H
14and hexene, C
6H
12
(b)Responding Variable: Sootiness of flames
(c)Constant Variable: Volume of hexane, C
6H
14and hexene, C
6H
12
Materials:Hexane, C
6H
14, hexene, C
6H
12, wooden splinter, matches and filter paper
Apparatus: Evaporating dish and measuring cylinder
EXPERIMENT : Comparing Alkanes and Alkenes
Aim:To compare hexane, C
6H
14and hexene, C
6H
12for sootiness of flames during
combustion.
Problem Statement: Do alkanes and alkenes burn with the same quantity of soot?
Hypothesis:Hexene, C
6H
12burns with a more sooty flame compared to hexane, C
6H
14.
Variables:-
(a)Manipulated Variable: Hexane, C
6H
14and hexene, C
6H
12
(b)Responding Variable: Sootiness of flames
(c)Constant Variable: Volume of hexane, C
6H
14and hexene, C
6H
12
Materials:Hexane, C
6H
14, hexene, C
6H
12, wooden splinter, matches and filter paper
Apparatus: Evaporating dish and measuring cylinder
EXPERIMENT : Comparing Alkanes and Alkenes
Procedure:
1. Pour 2 cm
3
of hexane, C
6H
14into an evaporating dish.
2. Use a lighted wooden splinter to ignite hexane, C
6H
14.
3. When hexane, C
6H
14starts to burn, place a piece of filter paper above the flame as
shown in Figure.
4. Repeat steps 1 to 3 using hexene, C
6H
12to replace hexane, C
6H
14.
5. Record the observation of the sootiness of the flame and the quantity of soot formed
on the filter paper.
EXPERIMENT : Comparing Alkanes and Alkenes
1. Pour 2 cm
3
of hexane, C
6H
14into an evaporating dish.
2. Use a lighted wooden splinter to ignite hexane, C
6H
14.
3. When hexane, C
6H
14starts to burn, place a piece of filter paper above the flame as
shown in Figure.
4. Repeat steps 1 to 3 using hexene, C
6H
12to replace hexane, C
6H
14.
5. Record the observation of the sootiness of the flame and the quantity of soot formed
on the filter paper.
EXPERIMENT : Comparing Alkanes and Alkenes
B. Reaction with Bromine Water, Br
2
Aim:To compare hexane, C
6H
14and hexene, C
6H
12using bromine water, Br
2
Hypothesis:Hexene, C
6H
12decolourises the brown colour of bromine water, Br
2while hexane,
C
6H
14does not decolourise the brown colour of bromine water, Br
2.
Variables:-
(a)Manipulated Variable: Hexane, C
6H
14and hexene, C
6H
12
(b)Responding Variable: Colour change of bromine water, Br
2
(c)Constant Variable: Volume of hexane, C
6H
14and hexene, C
6H
12
Materials:Hexane, C
6H
14, hexene, C
6H
12and bromine water, Br
2in 1,1,1-trichloroethane,
CH
3CCl
3
Apparatus: Test tube, measuring cylinder and dropper.
EXPERIMENT : Comparing Alkanes and Alkenes
2
Aim:To compare hexane, C
6H
14and hexene, C
6H
12using bromine water, Br
2
Hypothesis:Hexene, C
6H
12decolourises the brown colour of bromine water, Br
2while hexane,
C
6H
14does not decolourise the brown colour of bromine water, Br
2.
Variables:-
(a)Manipulated Variable: Hexane, C
6H
14and hexene, C
6H
12
(b)Responding Variable: Colour change of bromine water, Br
2
(c)Constant Variable: Volume of hexane, C
6H
14and hexene, C
6H
12
Materials:Hexane, C
6H
14, hexene, C
6H
12and bromine water, Br
2in 1,1,1-trichloroethane,
CH
3CCl
3
Apparatus: Test tube, measuring cylinder and dropper.
EXPERIMENT : Comparing Alkanes and Alkenes
Procedure:
1. Pour 2 cm
3
of hexane, C
6H
14into a test tube.
2. Add 2 -3 drops of bromine water, Br
2in 1,1,1-trichloroethane, CH
3CCl
3to hexane, C
6H
14
as shown in Figure.
3. Shake the mixture.
4. Record all observations.
5. Repeat steps 1 to 4 using hexene, C
6H
12to replace hexane, C
6H
14.
EXPERIMENT : Comparing Alkanes and Alkenes
1. Pour 2 cm
3
of hexane, C
6H
14into a test tube.
2. Add 2 -3 drops of bromine water, Br
2in 1,1,1-trichloroethane, CH
3CCl
3to hexane, C
6H
14
as shown in Figure.
3. Shake the mixture.
4. Record all observations.
5. Repeat steps 1 to 4 using hexene, C
6H
12to replace hexane, C
6H
14.
EXPERIMENT : Comparing Alkanes and Alkenes
C. Reaction with Acidified Potassium Manganate(VII), KMnO
4Solution
Aim:To compare hexane, C
6H
14and hexene, C
6H
12using acidified potassium manganate(VII),
KMnO
4solution.
Hypothesis:Hexene, C
6H
12decolourises the purple colour of acidified potassium
manganate(VII), KMnO
4solution while hexane, C
6H
14does not decolourise
acidified potassium manganate(VII), KMnO
4solution.
Variables:-
(a)Manipulated Variable: Hexane, C
6H
14and hexene, C
6H
12
(b)Responding Variable: Colour change of acidified potassium manganate(VII), KMnO
4
solution
(c)Constant Variable: Volume of hexane, C
6H
14and hexene, C
6H
12
Materials:Hexane, C
6H
14, hexene, C
6H
12and acidified potassium manganate(VII), KMnO
4
solution.
Apparatus: Test tube, measuring cylinder and dropper.
EXPERIMENT : Comparing Alkanes and Alkenes
4Solution
Aim:To compare hexane, C
6H
14and hexene, C
6H
12using acidified potassium manganate(VII),
KMnO
4solution.
Hypothesis:Hexene, C
6H
12decolourises the purple colour of acidified potassium
manganate(VII), KMnO
4solution while hexane, C
6H
14does not decolourise
acidified potassium manganate(VII), KMnO
4solution.
Variables:-
(a)Manipulated Variable: Hexane, C
6H
14and hexene, C
6H
12
(b)Responding Variable: Colour change of acidified potassium manganate(VII), KMnO
4
solution
(c)Constant Variable: Volume of hexane, C
6H
14and hexene, C
6H
12
Materials:Hexane, C
6H
14, hexene, C
6H
12and acidified potassium manganate(VII), KMnO
4
solution.
Apparatus: Test tube, measuring cylinder and dropper.
EXPERIMENT : Comparing Alkanes and Alkenes
Procedure:
1. Pour 2 cm
3
of hexane, C
6H
14into a test tube.
2. Add 2 –3 drops of acidified potassium manganate(VII), KMnO
4solution to hexane, C
6H
14,
as shown in Figure.
3. Shake the mixture.
4. Record all the observations.
5. Repeat steps 1 to 4 using hexene, C
6H
12to replace hexane, C
6H
14.
EXPERIMENT : Comparing Alkanes and Alkenes
1. Pour 2 cm
3
of hexane, C
6H
14into a test tube.
2. Add 2 –3 drops of acidified potassium manganate(VII), KMnO
4solution to hexane, C
6H
14,
as shown in Figure.
3. Shake the mixture.
4. Record all the observations.
5. Repeat steps 1 to 4 using hexene, C
6H
12to replace hexane, C
6H
14.
EXPERIMENT : Comparing Alkanes and Alkenes
Results:
EXPERIMENT : Comparing Alkanes and Alkenes
Experiment Observation
A
Hexene burns with a more sooty flame compared to
hexane
B
Hexene decolourises the brown colour of bromine water
while hexane does not decolourise the brown colour of
bromine water
C
Hexene decolourises the purple colour of acidified
KMnO
4solutionwhile hexane does not decolourise the
purple colour of acidified KMnO
4solution
EXPERIMENT : Comparing Alkanes and Alkenes
Experiment Observation
A
Hexene burns with a more sooty flame compared to
hexane
B
Hexene decolourises the brown colour of bromine water
while hexane does not decolourise the brown colour of
bromine water
C
Hexene decolourises the purple colour of acidified
KMnO
4solutionwhile hexane does not decolourise the
purple colour of acidified KMnO
4solution
Discussion
1.(a) Calculate the percentage of carbon by mass per molecule in hexane, C
6H
14and
hexene, C
6H
12.
Answer:-
1.(b) State the relationship between the percentage of carbon by mass per molecule
in hexane, C
6H
14and hexene, C
6H
12, and the sootiness of the flames.
Answer:-
The higher the percentage of carbon by mass per molecule, the more soot
is produced by the flame.
1.(a) Calculate the percentage of carbon by mass per molecule in hexane, C
6H
14and
hexene, C
6H
12.
Answer:-
1.(b) State the relationship between the percentage of carbon by mass per molecule
in hexane, C
6H
14and hexene, C
6H
12, and the sootiness of the flames.
Answer:-
The higher the percentage of carbon by mass per molecule, the more soot
is produced by the flame.
Discussion
2.(a) Suggest two reagents that can be used to distinguish between hexane, C
6H
14
and hexene, C
6H
12. Explain your answer.
Answer:-
Acidic solution of potassium manganate (VII) and bromine
Hexane does not decolorize the brown colour of the bromine water but the hexane
decolorizes the brown bromine water.
Hexane does not decolorize the purple colour of acidic potassium manganate (VII)
solution but hexene decolorize the purple colour of acidic potassium manganate (VII)
solution
2.(a) Suggest two reagents that can be used to distinguish between hexane, C
6H
14
and hexene, C
6H
12. Explain your answer.
Answer:-
Acidic solution of potassium manganate (VII) and bromine
Hexane does not decolorize the brown colour of the bromine water but the hexane
decolorizes the brown bromine water.
Hexane does not decolorize the purple colour of acidic potassium manganate (VII)
solution but hexene decolorize the purple colour of acidic potassium manganate (VII)
solution
Discussion
Answer:-
Hexane is a saturated hydrocarbon that contains a single covalent bond between
carbon atoms. The addition reaction does not occur when an acidic solution of
potassium manganate (VII) is added.
Hexene is an unsaturated hydrocarbon that contains a double double covalent
bond between carbon atoms, -C = C-. The addition reaction occurs when an
acidic solution of potassium manganate (VII) is produced to produce hexanadiol.
Balanced equation :
C
6H
12+ H
2O + 2[O] → C
6H
12(OH)
2
Hexene Hexanadiol
2. (b)Explain the difference in reactivity of hexane, C6H14 and hexene, C6H12 in
terms of chemical bonds in their molecules.
Answer:-
Hexane is a saturated hydrocarbon that contains a single covalent bond between
carbon atoms. The addition reaction does not occur when an acidic solution of
potassium manganate (VII) is added.
Hexene is an unsaturated hydrocarbon that contains a double double covalent
bond between carbon atoms, -C = C-. The addition reaction occurs when an
acidic solution of potassium manganate (VII) is produced to produce hexanadiol.
Balanced equation :
C
6H
12+ H
2O + 2[O] → C
6H
12(OH)
2
Hexene Hexanadiol
2. (b)Explain the difference in reactivity of hexane, C6H14 and hexene, C6H12 in
terms of chemical bonds in their molecules.
Discussion
Answer:-
When bromine water is dropped into a liquid hydrocarbon, the brown colour
of bromine water decolorised.
OR
When an acidic solution of potassium manganate (VII) is dropped into the
hydrocarbon, the purple colorof potassium manganate (VII) decolorised.
3. What is the operational definition of unsaturated hydrocarbons in this
experiment?
Answer:-
When bromine water is dropped into a liquid hydrocarbon, the brown colour
of bromine water decolorised.
OR
When an acidic solution of potassium manganate (VII) is dropped into the
hydrocarbon, the purple colorof potassium manganate (VII) decolorised.
3. What is the operational definition of unsaturated hydrocarbons in this
experiment?
0102
0304
Alkene burns a sootier flame
compared to alkane because
the percentage of carbon by
mass per molecule in alkene
is higher than alkane
Alkenes react with bromine
water and acidified KMnO
4
solution while alkanes do not
show any changes with these
two reagents
The soot formed is carbon.
The greater the number of
carbon atoms per molecule,
the higher the percentage of
carbon by mass per molecule
and the more soot is
produced by the flame
Alkenes are more reactive
than alkanes due to the
presence of double bonds in
alkene molecules. Addition
reaction occur in alkenes but
does not occur in alkanes
Comparison Between Alkanes and Alkenes
0304
Alkene burns a sootier flame
compared to alkane because
the percentage of carbon by
mass per molecule in alkene
is higher than alkane
Alkenes react with bromine
water and acidified KMnO
4
solution while alkanes do not
show any changes with these
two reagents
The soot formed is carbon.
The greater the number of
carbon atoms per molecule,
the higher the percentage of
carbon by mass per molecule
and the more soot is
produced by the flame
Alkenes are more reactive
than alkanes due to the
presence of double bonds in
alkene molecules. Addition
reaction occur in alkenes but
does not occur in alkanes
Comparison Between Alkanes and Alkenes
Preparation of Alcohols
Fermentation of Glucose
Fermentation is the process in which yeast acts on carbohydrates (sugar
or starch) to produce ethanol, C
2H
5OH and carbon dioxide, CO
2in the
absence of oxygen, O
2
Yeast contains the enzyme zymase that acts as a catalyst, which breaks
down sugar or starch into glucose. Fermentation of glucose will produce
ethanol and carbon dioxide gas.
The ethanol, C
2H
5OH produced is purified by fractional distillation
C
6H
12O
6(aq)
Zymase enzyme
2C
2H
5OH (l) + 2CO
2(g)
Glucose Carbon dioxideEthanol
Fermentation is the process in which yeast acts on carbohydrates (sugar
or starch) to produce ethanol, C
2H
5OH and carbon dioxide, CO
2in the
absence of oxygen, O
2
Yeast contains the enzyme zymase that acts as a catalyst, which breaks
down sugar or starch into glucose. Fermentation of glucose will produce
ethanol and carbon dioxide gas.
The ethanol, C
2H
5OH produced is purified by fractional distillation
C
6H
12O
6(aq)
Zymase enzyme
2C
2H
5OH (l) + 2CO
2(g)
Glucose Carbon dioxideEthanol
Hydration of Ethene
Ethene, C
2H
4reacts with steam (H
2O) at 300
o
C and pressure of 60 atmwith
the presence of phosphoric acid, H
3PO
4as a catalyst.
C
2H
4(g) + H
2O(g) C
2H
5OH (l)
EthanolEthene Steam
Ethene, C
2H
4reacts with steam (H
2O) at 300
o
C and pressure of 60 atmwith
the presence of phosphoric acid, H
3PO
4as a catalyst.
C
2H
4(g) + H
2O(g) C
2H
5OH (l)
EthanolEthene Steam
Aim:To prepare ethanol, C
2H
5OH through fermentation of glucose.
Materials:Glucose, C
6H
12O
6, yeast, limewater, distilled water and filter paper.
Apparatus: Conical flask, beaker, measuring cylinder, round-bottom flask, delivery tube,
stopper, test tube, thermometer, fractionating column, Liebig condenser,
retort stand, wire gauze, Bunsen burner, tripod stand, rubber tubing, filter
funnel and glass rod.
EXPERIMENT : Preparation of Ethanol, C
2H
5OH Through
Fermentation of Glucose
2H
5OH through fermentation of glucose.
Materials:Glucose, C
6H
12O
6, yeast, limewater, distilled water and filter paper.
Apparatus: Conical flask, beaker, measuring cylinder, round-bottom flask, delivery tube,
stopper, test tube, thermometer, fractionating column, Liebig condenser,
retort stand, wire gauze, Bunsen burner, tripod stand, rubber tubing, filter
funnel and glass rod.
EXPERIMENT : Preparation of Ethanol, C
2H
5OH Through
Fermentation of Glucose
EXPERIMENT : Preparation of Ethanol, C
2H
5OH Through
Fermentation of Glucose
Set up apparatus for fermentation
Set up apparatus for distillation
2H
5OH Through
Fermentation of Glucose
Set up apparatus for fermentation
Set up apparatus for distillation
Procedure:
1. Put 20 g of glucose, C
6H
12O
6into 200 cm
3
of distilled water into a conical flask.
2. Add 10 g of yeast into the conical flask and stir with a glass rod until the mixture is even.
3. Close the conical flask with a stopper connected to the delivery tube.
4.Insert the end of the delivery tube into the test tube as shown in Figure. Make sure the
end of the delivery tube is dipped into the limewater.
5. Place the apparatus at room temperature (30 °C) for three days.
6. After three days, filter the mixture from the conical flask.
7. The filtrate is poured into a round-bottom flask. The apparatus for distillation is set up as
shown in Figure.
8. Heat the filtrate in the water bath and collect the distillate at 78 °C.
9. Record the colour and smell of the distillate.
Results:
1.Ethanol, C
2H
5OH can be prepared through the fermentation of glucose, C
6H
12O
6.
2.Ethanol, C
2H
5OH is a colourless and volatile liquid at room temperature.
EXPERIMENT : Preparation of Ethanol, C
2H
5OH Through
Fermentation of Glucose
1. Put 20 g of glucose, C
6H
12O
6into 200 cm
3
of distilled water into a conical flask.
2. Add 10 g of yeast into the conical flask and stir with a glass rod until the mixture is even.
3. Close the conical flask with a stopper connected to the delivery tube.
4.Insert the end of the delivery tube into the test tube as shown in Figure. Make sure the
end of the delivery tube is dipped into the limewater.
5. Place the apparatus at room temperature (30 °C) for three days.
6. After three days, filter the mixture from the conical flask.
7. The filtrate is poured into a round-bottom flask. The apparatus for distillation is set up as
shown in Figure.
8. Heat the filtrate in the water bath and collect the distillate at 78 °C.
9. Record the colour and smell of the distillate.
Results:
1.Ethanol, C
2H
5OH can be prepared through the fermentation of glucose, C
6H
12O
6.
2.Ethanol, C
2H
5OH is a colourless and volatile liquid at room temperature.
EXPERIMENT : Preparation of Ethanol, C
2H
5OH Through
Fermentation of Glucose
Discussion
1. What is the function of yeast in the fermentation of glucose, C
6H
12O
6?
Answer:-
Yeast contains enzymes that act as catalysts to break down glucose into
ethanol and carbon dioxide .
2. Why must the end of the delivery tube be immersed in limewater?
Answer:-
To ensure that the gas released during fermentation is passed through
the lime water.
1. What is the function of yeast in the fermentation of glucose, C
6H
12O
6?
Answer:-
Yeast contains enzymes that act as catalysts to break down glucose into
ethanol and carbon dioxide .
2. Why must the end of the delivery tube be immersed in limewater?
Answer:-
To ensure that the gas released during fermentation is passed through
the lime water.
Discussion
3. Name the gas released in the fermentation of glucose, C
6H
12O
6.
Answer:-
Carbon dioxide gas
4. Name the product collected in fractional distillation at 78 °C.
Answer:-
Ethanol
3. Name the gas released in the fermentation of glucose, C
6H
12O
6.
Answer:-
Carbon dioxide gas
4. Name the product collected in fractional distillation at 78 °C.
Answer:-
Ethanol
Discussion
5. Explain why ethanol, C
2H
5OH from the filtrate can be separated at 78 °C.
Answer:-
The filtrate is a mixture of ethanol and water that has different
boiling points. The boiling point of ethanol is lower than that of water.
When the mixture is heated, ethanol boils first before water at the
temperature of 78 °C
The ethanol vapor formed at its boiling point will be condensed in a
Liebig condenser and then collected in a test tube.
5. Explain why ethanol, C
2H
5OH from the filtrate can be separated at 78 °C.
Answer:-
The filtrate is a mixture of ethanol and water that has different
boiling points. The boiling point of ethanol is lower than that of water.
When the mixture is heated, ethanol boils first before water at the
temperature of 78 °C
The ethanol vapor formed at its boiling point will be condensed in a
Liebig condenser and then collected in a test tube.
Discussion
6. Write the chemical equation for the fermentation of glucose, C
6H
12O
6.
Answer:-
7. Fermentation to produce ethanol, C2H5OH can also be carried out using fruits.
Explain why.
Answer:-
Yeast contains the enzyme zymase which can break down carbohydrate or
sucrose and fructose molecules found in fruits into glucose and then to
ethanol.
C
6H
12O
6(aq) 2C
2H
5OH (l) + 2CO
2(g)
Glucose
Yeast
Ethanol Carbon Dioxide
6. Write the chemical equation for the fermentation of glucose, C
6H
12O
6.
Answer:-
7. Fermentation to produce ethanol, C2H5OH can also be carried out using fruits.
Explain why.
Answer:-
Yeast contains the enzyme zymase which can break down carbohydrate or
sucrose and fructose molecules found in fruits into glucose and then to
ethanol.
C
6H
12O
6(aq) 2C
2H
5OH (l) + 2CO
2(g)
Glucose
Yeast
Ethanol Carbon Dioxide
Chemical Properties of Alcohols
Alcohols burn in excess oxygen, O
2to produce carbon dioxide, CO
2and water.
Alcohols are flammable and burn with a blue flame without soot.
The combustion of ethanol, C
2H
5OH releases large quantities of heat
Chemical Properties of Alcohols –
Combustion of Alcohols
Ethanol, C
2H
5OH can be used as fuel for rockets.
2C
2H
5OH (l) + 3O
2(g) 2CO
2(g) + 3H
2O (l)
Ethanol Carbon dioxide WaterOxygen
2to produce carbon dioxide, CO
2and water.
Alcohols are flammable and burn with a blue flame without soot.
The combustion of ethanol, C
2H
5OH releases large quantities of heat
Chemical Properties of Alcohols –
Combustion of Alcohols
Ethanol, C
2H
5OH can be used as fuel for rockets.
2C
2H
5OH (l) + 3O
2(g) 2CO
2(g) + 3H
2O (l)
Ethanol Carbon dioxide WaterOxygen
Alcohols can be oxidised to form carboxylic acids in the presence of
suitable oxidising agent
Common oxidising agents: acidified potassium manganate(VII),
KMnO
4solution and acidified potassium dichromate(VI), K
2Cr
2O
7
solution
Chemical Properties of Alcohols –
Oxidation of Alcohols
C
nH
2n+1OH (l) + 2[O]
n = 1, 2, 3…
Alcohol
C
mH
2m+1COOH + H
2O
m = 0, 1, 2, 3……
Carboxylic acid
suitable oxidising agent
Common oxidising agents: acidified potassium manganate(VII),
KMnO
4solution and acidified potassium dichromate(VI), K
2Cr
2O
7
solution
Chemical Properties of Alcohols –
Oxidation of Alcohols
C
nH
2n+1OH (l) + 2[O]
n = 1, 2, 3…
Alcohol
C
mH
2m+1COOH + H
2O
m = 0, 1, 2, 3……
Carboxylic acid
The purplecolour of acidified KMnO
4solution is decolourised in this reaction.
The orangecolour of acidified K
2Cr
2O
7solution turns greenwhen it reacts
with ethanol.
Example:-
(a) Oxidation of ethanol, C
2H
5OH by acidified
potassium manganate(VII), KMnO
4solution.
C
2H
5OH (l) + 2[O]
Ethanol
CH
3COOH (aq) + H
2O (l)
Ethanoic
acid
4solution is decolourised in this reaction.
The orangecolour of acidified K
2Cr
2O
7solution turns greenwhen it reacts
with ethanol.
Example:-
(a) Oxidation of ethanol, C
2H
5OH by acidified
potassium manganate(VII), KMnO
4solution.
C
2H
5OH (l) + 2[O]
Ethanol
CH
3COOH (aq) + H
2O (l)
Ethanoic
acid
Dehydration of alcohols involves the removal of a water molecule
from each alcohol molecule to produce a corresponding alkene.
Chemical Properties of Alcohols –
Dehydration of Alcohols
C
nH
2n+1OH C
nH
2n+ H
2O
Water molecules are removed from alcohols when alcohol vapour is flowed
over a strongly heated catalyst, such as porcelain chips, aluminium oxide,
alumina or concentrated sulphuric acid
from each alcohol molecule to produce a corresponding alkene.
Chemical Properties of Alcohols –
Dehydration of Alcohols
C
nH
2n+1OH C
nH
2n+ H
2O
Water molecules are removed from alcohols when alcohol vapour is flowed
over a strongly heated catalyst, such as porcelain chips, aluminium oxide,
alumina or concentrated sulphuric acid
Alkene that produced, has the following characteristics:
(i) burns with yellow sooty flame,
(ii) decolourises the brown colour of bromine water, Br2 to colourless,
(iii) decolourises the purple colour of potassium manganate(VII), KMnO4
solution
to colourless.
Example:-
(a) Dehydration of ethanol, C
2H
5OH
C
2H
5OH (l)
Ethanol
C
2H
4(g) + H
2O (l)
Ethene Water
The hydroxyl group, together with the hydrogen atom,
are removed from the adjacent carbon atoms to form water, H
2O.
(i) burns with yellow sooty flame,
(ii) decolourises the brown colour of bromine water, Br2 to colourless,
(iii) decolourises the purple colour of potassium manganate(VII), KMnO4
solution
to colourless.
Example:-
(a) Dehydration of ethanol, C
2H
5OH
C
2H
5OH (l)
Ethanol
C
2H
4(g) + H
2O (l)
Ethene Water
The hydroxyl group, together with the hydrogen atom,
are removed from the adjacent carbon atoms to form water, H
2O.
Aim:To study the chemical properties of ethanol, C
2H
5OH.
Materials:Ethanol, C
2H
5OH, porcelain chips, glass wool, potassium dichromate(VI), K
2Cr
2O
7
solution, potassium manganate(VII), KMnO
4solution, concentrated sulphuric acid,
H
2SO
4, blue litmus paper, bromine water, Br
2.
Apparatus: Test tube, boiling tube, boiling tube stopper with delivery tube, retort stand, test
tube holder, Bunsen burner, measuring cylinder, dropper and beaker.
EXPERIMENT : Chemical Properties of Ethanol
2H
5OH.
Materials:Ethanol, C
2H
5OH, porcelain chips, glass wool, potassium dichromate(VI), K
2Cr
2O
7
solution, potassium manganate(VII), KMnO
4solution, concentrated sulphuric acid,
H
2SO
4, blue litmus paper, bromine water, Br
2.
Apparatus: Test tube, boiling tube, boiling tube stopper with delivery tube, retort stand, test
tube holder, Bunsen burner, measuring cylinder, dropper and beaker.
EXPERIMENT : Chemical Properties of Ethanol
EXPERIMENT : Chemical Properties of Ethanol
A. Oxidation of Ethanol, C
2H
5OH
Procedure:
1. Pour 5 cm
3
of potassium dichromate(VI), K
2Cr
2O
7solution into a boiling tube.
2. Add 10 drops of concentrated sulphuric acid, H
2SO
4.
3. Gently heat the solution.
4. Add 3 cm
3
of ethanol, C
2H
5OH drop by drop into the boiling tube.
5. Connect the delivery tube to the boiling tube as shown in Figure. Heat the mixture with a
gentle flame until the mixture boils.
6.Collect the distillate in a test tube and test it with the blue litmus paper.
7.Repeat steps 1 to 6 by replacing potassium dichromate(VI), K
2Cr
2O
7solution with potassium
manganate(VII), KMnO
4solution.
A. Oxidation of Ethanol, C
2H
5OH
Procedure:
1. Pour 5 cm
3
of potassium dichromate(VI), K
2Cr
2O
7solution into a boiling tube.
2. Add 10 drops of concentrated sulphuric acid, H
2SO
4.
3. Gently heat the solution.
4. Add 3 cm
3
of ethanol, C
2H
5OH drop by drop into the boiling tube.
5. Connect the delivery tube to the boiling tube as shown in Figure. Heat the mixture with a
gentle flame until the mixture boils.
6.Collect the distillate in a test tube and test it with the blue litmus paper.
7.Repeat steps 1 to 6 by replacing potassium dichromate(VI), K
2Cr
2O
7solution with potassium
manganate(VII), KMnO
4solution.
Results:
EXPERIMENT : Chemical Properties of Ethanol
Test on Distillate Observation
Colour change of potassium
dichromate(VI), K
2Cr
2O
7solution
The mixture changes from orange colour to
green
Colour change of potassium
manganate(VII), KMnO
4solution
The mixture changes from purple colour to
colourless
Colour of distillate Colourless
Smell of distillate
Smells like vinegar
Effect on blue litmus paper
Changes the blue litmus paper to red
EXPERIMENT : Chemical Properties of Ethanol
Test on Distillate Observation
Colour change of potassium
dichromate(VI), K
2Cr
2O
7solution
The mixture changes from orange colour to
green
Colour change of potassium
manganate(VII), KMnO
4solution
The mixture changes from purple colour to
colourless
Colour of distillate Colourless
Smell of distillate
Smells like vinegar
Effect on blue litmus paper
Changes the blue litmus paper to red
Discussion
1. What is the product formed by the oxidation reaction of ethanol, C
2H
5OH?
Answer:-
Ethanoic acid
2. Name the oxidising agent used in this experiment.
Answer:-
a) Potassium dichromate (VI) solution
b)Potassium manganate(VII) solution
1. What is the product formed by the oxidation reaction of ethanol, C
2H
5OH?
Answer:-
Ethanoic acid
2. Name the oxidising agent used in this experiment.
Answer:-
a) Potassium dichromate (VI) solution
b)Potassium manganate(VII) solution
Discussion
3. Write the chemical equation of the reaction that occurs.
Answer:-
4. What is the property of the product of alcohol oxidation?
Answer:-
Acidic
C
2H
5OH + 2[O] CH
3COOHOH + H
2O
Ethanol Ethanoic acid Water
Conclusion :The oxidation of ethanol, C
2H
5OH produces ethanoic acid, CH
3COOH.
3. Write the chemical equation of the reaction that occurs.
Answer:-
4. What is the property of the product of alcohol oxidation?
Answer:-
Acidic
C
2H
5OH + 2[O] CH
3COOHOH + H
2O
Ethanol Ethanoic acid Water
Conclusion :The oxidation of ethanol, C
2H
5OH produces ethanoic acid, CH
3COOH.
EXPERIMENT : Chemical Properties of Ethanol
B. Dehydration of Ethanol, C
2H
5OH
B. Dehydration of Ethanol, C
2H
5OH
EXPERIMENT : Chemical Properties of Ethanol
B. Dehydration of Ethanol, C
2H
5OH
Procedure:
1. Place the glass wool in a boiling tube.
2. Pour 2 cm
3
of ethanol, C
2H
5OH into the boiling tube to wet the glass wool.
3. Place the porcelain chips in the middle of the boiling tube as shown in Figure.
4. Heat the porcelain chips with a strong flame. Heat the glass wool with a gentle flame to
vaporise the ethanol, C
2H
5OH and the vapour is flowed through the heated porcelain chips.
5. Collect two test tubes of the gas released, as shown in Figure.
6. (i) Add a few drops of bromine water, Br
2into the first test tube and shake.
(ii) Add a few drops of acidified potassium manganate(VII ), KMnO
4solution into the second
test tube and shake.
B. Dehydration of Ethanol, C
2H
5OH
Procedure:
1. Place the glass wool in a boiling tube.
2. Pour 2 cm
3
of ethanol, C
2H
5OH into the boiling tube to wet the glass wool.
3. Place the porcelain chips in the middle of the boiling tube as shown in Figure.
4. Heat the porcelain chips with a strong flame. Heat the glass wool with a gentle flame to
vaporise the ethanol, C
2H
5OH and the vapour is flowed through the heated porcelain chips.
5. Collect two test tubes of the gas released, as shown in Figure.
6. (i) Add a few drops of bromine water, Br
2into the first test tube and shake.
(ii) Add a few drops of acidified potassium manganate(VII ), KMnO
4solution into the second
test tube and shake.
Discussion
1. Name the gas released when ethanol, C
2H
5OH undergoes dehydration.
Answer:-
Ethene
2. State the function of porcelain chips.
Answer:-
As a catalyst
1. Name the gas released when ethanol, C
2H
5OH undergoes dehydration.
Answer:-
Ethene
2. State the function of porcelain chips.
Answer:-
As a catalyst
Discussion
3. Write the chemical equation for the dehydration of alcohol, C
2H
5OH.
Answer:-
Conclusion :Dehydration of ethanol, C
2H
5OH produces ethene, C
2H
4.
C
2H
5OH
Ethanol Ethene Water
C
2H
4 + H
2O
3. Write the chemical equation for the dehydration of alcohol, C
2H
5OH.
Answer:-
Conclusion :Dehydration of ethanol, C
2H
5OH produces ethene, C
2H
4.
C
2H
5OH
Ethanol Ethene Water
C
2H
4 + H
2O
Chemical Properties of Carboxylic Acids
Carboxylic acids can be produced from the oxidation of alcohol.
Ethanoic acid, CH
3COOH is produced when ethanol, C
2H
5OH is
oxidised by an oxidising agent through the reflux method.
Carboxylic acids can be produced from the oxidation of alcohol.
Ethanoic acid, CH
3COOH is produced when ethanol, C
2H
5OH is
oxidised by an oxidising agent through the reflux method.
Reflux method is to ensure that
ethanol reacts completely with the
oxidising agent.
A Liebig condenser that is fitted
upright into a round-bottom flask will
condense ethanol vapour to liquid
ethanol.
Liquid ethanol flows back into the
round-bottom flask to react
completely with the oxidising agent
Chemical Properties of Carboxylic Acids
ethanol reacts completely with the
oxidising agent.
A Liebig condenser that is fitted
upright into a round-bottom flask will
condense ethanol vapour to liquid
ethanol.
Liquid ethanol flows back into the
round-bottom flask to react
completely with the oxidising agent
Chemical Properties of Carboxylic Acids
The chemical properties of carboxylic acids are studied through the chemical
reactions of ethanoic acid, CH
3COOH.
The chemical properties of carboxylic acids are determined by the carboxyl,
-COOH functional group.
Chemical Properties of Carboxylic Acids
reactions of ethanoic acid, CH
3COOH.
The chemical properties of carboxylic acids are determined by the carboxyl,
-COOH functional group.
Chemical Properties of Carboxylic Acids
(a)Carboxylic acid + Base Carboxylate salt + Water
2CH
3COOH(aq) + CuO(s) → (CH
3COO)
2Cu(aq) + H
2O(l)
Chemical Reactions of Ethanoic Acid,
CH
3COOH
(b) Carboxylic acid + Metal carbonateCarboxylate salt + Water + Carbon dioxide
2CH
3COOH(aq) + Na
2CO
3(s) → 2CH
3COONa (aq) + H
2O(l) + CO
2(g)
(c) Carboxylic acid + Metal Carboxylate salt + Hydrogen
2CH
3COOH(aq) + Mg(s) → (CH
3COO)
2Mg(aq) + H
2(g)
2CH
3COOH(aq) + CuO(s) → (CH
3COO)
2Cu(aq) + H
2O(l)
Chemical Reactions of Ethanoic Acid,
CH
3COOH
(b) Carboxylic acid + Metal carbonateCarboxylate salt + Water + Carbon dioxide
2CH
3COOH(aq) + Na
2CO
3(s) → 2CH
3COONa (aq) + H
2O(l) + CO
2(g)
(c) Carboxylic acid + Metal Carboxylate salt + Hydrogen
2CH
3COOH(aq) + Mg(s) → (CH
3COO)
2Mg(aq) + H
2(g)
Reaction with Alcohols
•Carboxylic acids react with alcohols to produce esters and water
•This reaction is called esterification, with the presence of concentrated
sulphuric acid, H
2SO
4as a catalyst
C
mH
2m+1COOH + C
nH
2n+1OH C
mH
2m+1COOC
nH
2n+1+ H
2O
Carboxylic acid Alcohol Ester Water
H2SO4
Concentrated
•Carboxylic acids react with alcohols to produce esters and water
•This reaction is called esterification, with the presence of concentrated
sulphuric acid, H
2SO
4as a catalyst
C
mH
2m+1COOH + C
nH
2n+1OH C
mH
2m+1COOC
nH
2n+1+ H
2O
Carboxylic acid Alcohol Ester Water
H2SO4
Concentrated
Reaction with Alcohols
Example:
When a mixture of glacial ethanoic acid, CH
3COOH and ethanol, C
2H
5OH, with a few drops of
concentrated sulphuric acid, H
2SO
4, is heated, an ester called ethyl ethanoate, CH
3COOC
2H
5is
formed.
•Ethyl ethanoate, CH
3COOC
2H
5is a colourless liquid that has the sweet fruity smell and
insoluble in water and less dense than water.
•Concentrated sulphuric acid, H
2SO
4is a catalyst in the esterification reaction.
Example:
When a mixture of glacial ethanoic acid, CH
3COOH and ethanol, C
2H
5OH, with a few drops of
concentrated sulphuric acid, H
2SO
4, is heated, an ester called ethyl ethanoate, CH
3COOC
2H
5is
formed.
•Ethyl ethanoate, CH
3COOC
2H
5is a colourless liquid that has the sweet fruity smell and
insoluble in water and less dense than water.
•Concentrated sulphuric acid, H
2SO
4is a catalyst in the esterification reaction.
Ethanoic acid
Carboxylic acid + Base Carboxylate salt + Water
2CH
3COOH(aq) + CuO(s) → (CH
3COO)
2Cu(aq) + H
2O(l)
Product
name: Copper
(II) Ethanoate
Carboxylic acid + Base Carboxylate salt + Water
2CH
3COOH(aq) + CuO(s) → (CH
3COO)
2Cu(aq) + H
2O(l)
Product
name: Copper
(II) Ethanoate
Ethanoic acid
Excess Mg
powder
Carboxylic acid + Metal Carboxylate salt + Hydrogen
2CH
3COOH(aq) + Mg(s) → (CH
3COO)
2Mg(aq) + H
2(g)
Product
name:
Magnesium
Ethanoate
Excess Mg
powder
Carboxylic acid + Metal Carboxylate salt + Hydrogen
2CH
3COOH(aq) + Mg(s) → (CH
3COO)
2Mg(aq) + H
2(g)
Product
name:
Magnesium
Ethanoate
Product name: Sodium Ethanoate
Ethanoic acid
Sodium carbonate powder
Carboxylic acid + Metal carbonateCarboxylate salt + Water + Carbon dioxide
2CH
3COOH(aq) + Na
2CO
3(s) → 2CH
3COONa (aq) + H
2O(l) + CO
2(g)
Ethanoic acid
Sodium carbonate powder
Carboxylic acid + Metal carbonateCarboxylate salt + Water + Carbon dioxide
2CH
3COOH(aq) + Na
2CO
3(s) → 2CH
3COONa (aq) + H
2O(l) + CO
2(g)
ESTER
Non Hydrocarbon
-Containscarbon, hydrogen and oxygen atoms.
Functional Group
-Carboxylate,
General Formula
-C
mH
2m+1COOC
nH
2n+1; m=0,1,2,3.... and n =1,2,3...
Esters are produced when carboxylic
acids react with alcohols
Carboxylic acid + Alcohol Ester + Water
Non Hydrocarbon
-Containscarbon, hydrogen and oxygen atoms.
Functional Group
-Carboxylate,
General Formula
-C
mH
2m+1COOC
nH
2n+1; m=0,1,2,3.... and n =1,2,3...
Esters are produced when carboxylic
acids react with alcohols
Carboxylic acid + Alcohol Ester + Water
Ester
C
mH
2m+1COOH + C
nH
2n+1OH C
mH
2m+1COOC
nH
2n+1+ H
2O
Carboxylic acid Alcohol Ester Water
•The general formula of ester: combining parts of the alcohol molecular formula
and parts of the carboxylic acid molecular formula, with the removal of one water
molecule.
m=0,1,2,3.... n =1,2,3...
•The general formula of esters can also be written as:
R is C
mH
2m+1from carboxylic acid
R’ is C
nH
2n+1from alcohol
C
mH
2m+1COOH + C
nH
2n+1OH C
mH
2m+1COOC
nH
2n+1+ H
2O
Carboxylic acid Alcohol Ester Water
•The general formula of ester: combining parts of the alcohol molecular formula
and parts of the carboxylic acid molecular formula, with the removal of one water
molecule.
m=0,1,2,3.... n =1,2,3...
•The general formula of esters can also be written as:
R is C
mH
2m+1from carboxylic acid
R’ is C
nH
2n+1from alcohol
Naming of Ester
Part two:
Derived from carboxylic
acid, the name ends with
“oate”.
Part one:
Derived from alcohol, the
name ends with “yl”.
Example:
Naming of the first part Naming of the second part Name of ester
Methanol ⇒Methyl Methanoicacid ⇒Methanoate Methyl methanoate
Ethanol ⇒Ethyl Ethanoic acid ⇒Ethanoate Ethyl ethanoate
Propanol ⇒Propyl Propanoic acid ⇒Propanoate Propyl propanoate
Part two:
Derived from carboxylic
acid, the name ends with
“oate”.
Part one:
Derived from alcohol, the
name ends with “yl”.
Example:
Naming of the first part Naming of the second part Name of ester
Methanol ⇒Methyl Methanoicacid ⇒Methanoate Methyl methanoate
Ethanol ⇒Ethyl Ethanoic acid ⇒Ethanoate Ethyl ethanoate
Propanol ⇒Propyl Propanoic acid ⇒Propanoate Propyl propanoate
Naming of Ester
•Eliminate hydroxyl
group -OH from
carboxylic acid ,
HCOOH.
•Remove H atom
from the hydroxyl
group of alcohol,
C
2H
5OH.
•Combine the two
remaining parts
by forming an
ester link -COO-
•Eliminate hydroxyl
group -OH from
carboxylic acid ,
HCOOH.
•Remove H atom
from the hydroxyl
group of alcohol,
C
2H
5OH.
•Combine the two
remaining parts
by forming an
ester link -COO-
Esterification Reaction
Example:
The esterification reaction between ethanoic acid, CH3COOH and ethanol, C2H5OH
forms ethyl ethanoate, CH3COOC2H5 with the presence of concentrated sulphuric
acid, H2SO4 as a catalyst.
•Ethyl ethanoate, CH
3COOC
2H
5is a colourless liquid that has the sweet fruity smell and
insoluble in water and less dense than water.
•Concentrated sulphuric acid, H
2SO
4is a catalyst in the esterification reaction.
Example:
The esterification reaction between ethanoic acid, CH3COOH and ethanol, C2H5OH
forms ethyl ethanoate, CH3COOC2H5 with the presence of concentrated sulphuric
acid, H2SO4 as a catalyst.
•Ethyl ethanoate, CH
3COOC
2H
5is a colourless liquid that has the sweet fruity smell and
insoluble in water and less dense than water.
•Concentrated sulphuric acid, H
2SO
4is a catalyst in the esterification reaction.
Physical Properties of Esters
Aim:To study the reaction of ethanoic acid, CH
3COOH with ethanol, C
2H
5OH.
Materials:Glacial ethanoic acid, CH
3COOH, absolute ethanol, C
2H
5OH and concentrated
sulphuric acid, H
2SO
4.
Apparatus: Beaker, Bunsen burner, test tube holder, boiling tube, dropper, glass rod and
measuring cylinder.
EXPERIMENT : Reaction of Ethanoic Acid with
Ethanol
3COOH with ethanol, C
2H
5OH.
Materials:Glacial ethanoic acid, CH
3COOH, absolute ethanol, C
2H
5OH and concentrated
sulphuric acid, H
2SO
4.
Apparatus: Beaker, Bunsen burner, test tube holder, boiling tube, dropper, glass rod and
measuring cylinder.
EXPERIMENT : Reaction of Ethanoic Acid with
Ethanol
Procedure:
1. Add 2 cm
3
of glacial ethanoic acid, CH
3COOH in a boiling tube.
2. Add 4 cm
3
of absolute ethanol, C
2H
5OH to the glacial ethanoic
acid, CH
3COOH.
3. Add five drops of concentrated sulphuric acid, H
2SO
4into the
mixture with a dropper and shake the boiling tube as shown in
Figure.
4. Heat the mixture gently with a small flame to bring it to a boil
for two to three minutes.
5. Pour the content of the boiling tube into a beaker half filled with
water.
6. Record the smell, colour and solubility of the product.
EXPERIMENT : Reaction of Ethanoic Acid with
Ethanol
1. Add 2 cm
3
of glacial ethanoic acid, CH
3COOH in a boiling tube.
2. Add 4 cm
3
of absolute ethanol, C
2H
5OH to the glacial ethanoic
acid, CH
3COOH.
3. Add five drops of concentrated sulphuric acid, H
2SO
4into the
mixture with a dropper and shake the boiling tube as shown in
Figure.
4. Heat the mixture gently with a small flame to bring it to a boil
for two to three minutes.
5. Pour the content of the boiling tube into a beaker half filled with
water.
6. Record the smell, colour and solubility of the product.
EXPERIMENT : Reaction of Ethanoic Acid with
Ethanol
Observation:-
EXPERIMENT : Reaction of Ethanoic Acid with
Ethanol
Test Observation
Colour Colourless
Smell Sweet and fruity smell
SolubilityDoes not dissolve in water
EXPERIMENT : Reaction of Ethanoic Acid with
Ethanol
Test Observation
Colour Colourless
Smell Sweet and fruity smell
SolubilityDoes not dissolve in water
Discussion
1. Name the reaction that occurs between glacial ethanoic acid, CH
3COOH and
ethanol, C
2H
5OH.
Answer:-
Esterification
2. Name the product formed from the reaction.
Answer:-
Ethyl ethanoate
1. Name the reaction that occurs between glacial ethanoic acid, CH
3COOH and
ethanol, C
2H
5OH.
Answer:-
Esterification
2. Name the product formed from the reaction.
Answer:-
Ethyl ethanoate
Discussion
3. Compare the density of the product formed with water.
Answer:-
Ethyl ethanoate is less dense than water.
4. What is the function of concentrated sulphuric acid, H
2SO
4?
Answer:-
As a catalyst.
3. Compare the density of the product formed with water.
Answer:-
Ethyl ethanoate is less dense than water.
4. What is the function of concentrated sulphuric acid, H
2SO
4?
Answer:-
As a catalyst.
Discussion
5. Write the equation for the reaction between ethanoic acid, CH
3COOH and
ethanol, C
2H
5OH.
Answer:-
CH
3COOH + C
2H
5OH → CH
3COOC
2H
5 + H
2O
Conclusion :Ethanoic acid, CH
3COOH reacts with ethanol, C
2H
5OH to
produce ester and water.
5. Write the equation for the reaction between ethanoic acid, CH
3COOH and
ethanol, C
2H
5OH.
Answer:-
CH
3COOH + C
2H
5OH → CH
3COOC
2H
5 + H
2O
Conclusion :Ethanoic acid, CH
3COOH reacts with ethanol, C
2H
5OH to
produce ester and water.
Self Assessment
Table below shows carbon compounds and their respective molecular formulae
Table below shows carbon compounds and their respective molecular formulae
Self Assessment
(a)(i). Compare and contrast the sootiness of flames of compound P and compound
Q when burnt in excess oxygen. Explain your answer.
[Relative atomic mass: C = 12, H = 1].
Answer:-
(a)(i). Compare and contrast the sootiness of flames of compound P and compound
Q when burnt in excess oxygen. Explain your answer.
[Relative atomic mass: C = 12, H = 1].
Answer:-
Self Assessment
(a)(ii). Table below shows the result of an experiment where compound P and
compound Q were separately shaken in bromine water in test tubes.
Answer:-
•P is a saturated hydrocarbon that has only a single bond between carbon atoms.
Addition reaction does not occur between compound P with bromine water.
•Q is an unsaturated hydrocarbon that has a double bond between carbon atoms.
•Addition reaction occurs between molecules Q with bromine water:
•C
3H
6 + Br
2 → C
3H
6Br
2
(a)(ii). Table below shows the result of an experiment where compound P and
compound Q were separately shaken in bromine water in test tubes.
Answer:-
•P is a saturated hydrocarbon that has only a single bond between carbon atoms.
Addition reaction does not occur between compound P with bromine water.
•Q is an unsaturated hydrocarbon that has a double bond between carbon atoms.
•Addition reaction occurs between molecules Q with bromine water:
•C
3H
6 + Br
2 → C
3H
6Br
2
Self Assessment
(b) 2.3 g of compound R burns completely in excess oxygen to produce carbon
dioxide gas and water. Write the chemical equation for the reaction and
determine the volume of carbon dioxide gas produced.
[Molar mass R = 46 gmol
−1
, molar volume of the gas at room condition = 24
dm
3
mol
−1
].
Answer:-
(b) 2.3 g of compound R burns completely in excess oxygen to produce carbon
dioxide gas and water. Write the chemical equation for the reaction and
determine the volume of carbon dioxide gas produced.
[Molar mass R = 46 gmol
−1
, molar volume of the gas at room condition = 24
dm
3
mol
−1
].
Answer:-
Self Assessment
(c) State two compounds from Table that react to produce ester. Name and draw
the structural formula for the ester formed.
Answer:-
•R and T
Ethyl ethanoate
(c) State two compounds from Table that react to produce ester. Name and draw
the structural formula for the ester formed.
Answer:-
•R and T
Ethyl ethanoate
Self Assessment
(d) Acid X is used as a catalyst during the esterification reaction. When the
concentrated acid X is spilt on the marble floor, gas bubbles are formed. Name
acid X and write the chemical equation for the reaction.
Answer:-
•Acid X is concentrated sulphuric acid Chemical equation:
2H
2SO
4 + CaCO
3→ CaSO
4+ H
2O + CO
2
(d) Acid X is used as a catalyst during the esterification reaction. When the
concentrated acid X is spilt on the marble floor, gas bubbles are formed. Name
acid X and write the chemical equation for the reaction.
Answer:-
•Acid X is concentrated sulphuric acid Chemical equation:
2H
2SO
4 + CaCO
3→ CaSO
4+ H
2O + CO
2
2.4 ISOMERS AND NAMING BASED ON IUPAC NOMENCLATURE
Aphenomenonwhereacompoundhas
thesamemolecularformulabutwithtwo
ormoredifferentstructuralformulae
The isomers have different
arrangementsofcarbonchains;either
eightstraightchainorbranchedchain
Theisomershavedifferentpositionsof
fucntionalgrouponthesamecarbonchain
Isomers are molecules
that have the same
molecular formula but
different structural
formulae.
Structural Isomerism
Position Isomerism
Chain Isomerism
Aphenomenonwhereacompoundhas
thesamemolecularformulabutwithtwo
ormoredifferentstructuralformulae
The isomers have different
arrangementsofcarbonchains;either
eightstraightchainorbranchedchain
Theisomershavedifferentpositionsof
fucntionalgrouponthesamecarbonchain
Isomers are molecules
that have the same
molecular formula but
different structural
formulae.
Structural Isomerism
Position Isomerism
Chain Isomerism
2.4 ISOMERS AND NAMING BASED ON IUPAC NOMENCLATURE
The isomers show
Same
chemical
properties
Different
physical
properties
Has the same
functional group
The more branches there
are, the lower the melting
point and boiling point are.
The number of isomers of a
molecule increases with the
increasing number of carbon atoms
in the molecule.
The isomers of alkanes are formed
by chain isomers only.
Isomers of alkenes, alkynes and
alcohol are formed from chain
isomers and position isomers .
The isomers show
Same
chemical
properties
Different
physical
properties
Has the same
functional group
The more branches there
are, the lower the melting
point and boiling point are.
The number of isomers of a
molecule increases with the
increasing number of carbon atoms
in the molecule.
The isomers of alkanes are formed
by chain isomers only.
Isomers of alkenes, alkynes and
alcohol are formed from chain
isomers and position isomers .
The prefix indicates the branch group, which is the alkyl group, with
the general formula C
nH
2n+1that is attached to the longest carbon
chain
The root name shows the number of carbon atoms in the longest carbon
chain
The suffix shows the homologous series
the general formula C
nH
2n+1that is attached to the longest carbon
chain
The root name shows the number of carbon atoms in the longest carbon
chain
The suffix shows the homologous series
Prefix
Root Name
Suffix
Prefix and root names“written
close together”
Number and name, write “ –“
Number and number, write “ , “
Root Name
Suffix
Prefix and root names“written
close together”
Number and name, write “ –“
Number and number, write “ , “
Step Example of alkane isomer Example of alkene isomer
1.Identifyandnamethe
longestcarbonchain,orthe
longestcarbonchain
containingthefunctional
groupforalkene.
Root name is obtained
Longest carbon chain: 3 carbons
Root name: Propane
Longest carbon chain: 4 carbons
Root name: Butene
1.Identifyandnamethe
longestcarbonchain,orthe
longestcarbonchain
containingthefunctional
groupforalkene.
Root name is obtained
Longest carbon chain: 3 carbons
Root name: Propane
Longest carbon chain: 4 carbons
Root name: Butene
Step Example of alkane isomerExample of alkene isomer
2.Identifybranchand
functionalgroup.
3.Numberthecarbonatoms
inthelongestchainfromone
endsothat:
thebranchgetsthe
lowestnumberfor
alkane.
thefunctionalgroup
getsthelowestnumberfor
alkene.
2.Identifybranchand
functionalgroup.
3.Numberthecarbonatoms
inthelongestchainfromone
endsothat:
thebranchgetsthe
lowestnumberfor
alkane.
thefunctionalgroup
getsthelowestnumberfor
alkene.
Step Example of alkane isomer Example of alkene isomer
4. State the position and name
of the branch, together with the
functional group.
The branches are:
• Two methyl groups.
• Both methyl groups are on
carbon number 2.
The branch is:
• A methyl group on carbon
number 3.
Prefix is obtained from the
name and position of the
branch.
Prefix: 2,2-dimethyl Prefix: 3-methyl
Suffix is obtained from the
homologous series.
Homologous series is alkane.
Suffix: “ane”
Homologous series is alkene.
Suffix: -1-ene (Double bond is on
the first carbon).
5. Name the isomer according
to the writing steps.
2,2-dimethylpropane 3-methylbut-1-ene
4. State the position and name
of the branch, together with the
functional group.
The branches are:
• Two methyl groups.
• Both methyl groups are on
carbon number 2.
The branch is:
• A methyl group on carbon
number 3.
Prefix is obtained from the
name and position of the
branch.
Prefix: 2,2-dimethyl Prefix: 3-methyl
Suffix is obtained from the
homologous series.
Homologous series is alkane.
Suffix: “ane”
Homologous series is alkene.
Suffix: -1-ene (Double bond is on
the first carbon).
5. Name the isomer according
to the writing steps.
2,2-dimethylpropane 3-methylbut-1-ene
Step Example of alkyne isomer Example of alcohol isomer
1.Identifyandnamethe
longestcarbonchain,orthe
longestcarbonchain
containingthefunctional
groupforalkene.
Root name is obtained
Longest carbon chain: 4 carbons
Root name: Butyne
Longest carbon chain: 3 carbons
Root name: Propanol
1.Identifyandnamethe
longestcarbonchain,orthe
longestcarbonchain
containingthefunctional
groupforalkene.
Root name is obtained
Longest carbon chain: 4 carbons
Root name: Butyne
Longest carbon chain: 3 carbons
Root name: Propanol
Step Example of alkyne isomer Example of alcohol isomer
2.Identifybranchand
functionalgroup.
3.Numberthecarbonatoms
inthelongestchainfromone
end,sothatthefunctional
groupgetsthelowestnumber.
2.Identifybranchand
functionalgroup.
3.Numberthecarbonatoms
inthelongestchainfromone
end,sothatthefunctional
groupgetsthelowestnumber.
Step Example of alkane isomer Example of alkene isomer
4. State the position and name
of the branch, together with the
functional group.
The branch is:
• One methyl on carbon
number 3.
The branch is:
• One methyl group on
carbon number 2.
Prefix is obtained from the
name and position of the
branch.
Prefix: 3-methyl Prefix: 2-methyl
Suffix is obtained from the
homologous series.
Homologous series is alkyne
Suffix: -1-yne (Triple bond is
on the first carbon)
Homologous series is alcohol
Suffix: -2-ol (Hydroxyl group is on
the second carbon)
5. Name the isomer according
to the writing steps.
3-methylbut-1-yne 2-methylpropan-2-ol
4. State the position and name
of the branch, together with the
functional group.
The branch is:
• One methyl on carbon
number 3.
The branch is:
• One methyl group on
carbon number 2.
Prefix is obtained from the
name and position of the
branch.
Prefix: 3-methyl Prefix: 2-methyl
Suffix is obtained from the
homologous series.
Homologous series is alkyne
Suffix: -1-yne (Triple bond is
on the first carbon)
Homologous series is alcohol
Suffix: -2-ol (Hydroxyl group is on
the second carbon)
5. Name the isomer according
to the writing steps.
3-methylbut-1-yne 2-methylpropan-2-ol
Starts with a molecule that has three carbon atoms
Isomerism in alcohol consists of chain isomers as well as
position isomers (different position of hydroxyl groups, -OH)
Propan-1-ol Propan-2-ol
2 number
of isomer
Isomerism in alcohol consists of chain isomers as well as
position isomers (different position of hydroxyl groups, -OH)
Propan-1-ol Propan-2-ol
2 number
of isomer
Butan-1-ol
4 number
of isomer
Butan-2-ol
2-methylpropan-1-ol
2-methylpropan-2-ol
4 number
of isomer
Butan-2-ol
2-methylpropan-1-ol
2-methylpropan-2-ol
Uses of Homologues Series in Daily Life
Uses of Alkane and Alkene
Fuel
Raw material in the
petrochemical
industry
Ethane
Production of ethene from
ethane to make detergents
and plastics.
Liquefied natural gas LNG
that contains ethane is used
as fuel for power stations.
Butane
Production of fuel for lighters and
portable stoves.
LPG cooking gas when mixed with
propane
Uses of Alkane and Alkene
Fuel
Raw material in the
petrochemical
industry
Ethane
Production of ethene from
ethane to make detergents
and plastics.
Liquefied natural gas LNG
that contains ethane is used
as fuel for power stations.
Butane
Production of fuel for lighters and
portable stoves.
LPG cooking gas when mixed with
propane
Uses of Homologues Series in Daily Life
Uses of Alkane and Alkene
Fuel
Raw material in the
petrochemical
industry
Ethene
Production of alcohol,
such as ethanol.
Production of
polythene, polyvinyl
chloride (PVC) and
polystyrene.
But-1,3-diene
Production of
synthetic rubber to
manufacture tyres
and hot water bags.
Uses of Alkane and Alkene
Fuel
Raw material in the
petrochemical
industry
Ethene
Production of alcohol,
such as ethanol.
Production of
polythene, polyvinyl
chloride (PVC) and
polystyrene.
But-1,3-diene
Production of
synthetic rubber to
manufacture tyres
and hot water bags.
Uses of Alcohols
1) Fuel
As fuel in clean fuel, bio fuel and gasohol.
Properties of alcohol
Highly flammable, and combustion releases
a lot of heat without soot.
2) Solvent
As a solvent in
Paint, lacquer, dyes and printing ink.
Cosmetics such as perfume, nail varnish,
cream and lotion.
Properties of alcohol
Colourless, good organic solvent, miscible in
water and volatile.
1) Fuel
As fuel in clean fuel, bio fuel and gasohol.
Properties of alcohol
Highly flammable, and combustion releases
a lot of heat without soot.
2) Solvent
As a solvent in
Paint, lacquer, dyes and printing ink.
Cosmetics such as perfume, nail varnish,
cream and lotion.
Properties of alcohol
Colourless, good organic solvent, miscible in
water and volatile.
Uses of Alcohols
3) Manufacturing sector
Raw materials in the production of vinegar,
explosives, polymer perspex and fibre.
Properties of alcohol
Chemically reactive.
4) Pharmaceutical products
In the medical field
Antiseptics for injections, surgeries and
general hygiene.
Solvent for medicines such as cough
medicine.
Properties of alcohol
Antiseptic, good organic solvent and
volatile.
3) Manufacturing sector
Raw materials in the production of vinegar,
explosives, polymer perspex and fibre.
Properties of alcohol
Chemically reactive.
4) Pharmaceutical products
In the medical field
Antiseptics for injections, surgeries and
general hygiene.
Solvent for medicines such as cough
medicine.
Properties of alcohol
Antiseptic, good organic solvent and
volatile.
Uses of Carboxylic Acid
Methanoicacid used in the rubber industry
for coagulation of latex.
Fatty acids are long chain are also used to
make soap.
Methanoicacid used in the rubber industry
for coagulation of latex.
Fatty acids are long chain are also used to
make soap.
Easily
evaporate
Fragrant
Ester Flavour
Methyl butanoate, C
3H
7COOCH
3 Apple
Penthylethanoate, CH
3COOC
5H
11 Banana
Ethyl butanoate, C
3H
7COOC
2H
5 Pineapple
evaporate
Fragrant
Ester Flavour
Methyl butanoate, C
3H
7COOCH
3 Apple
Penthylethanoate, CH
3COOC
5H
11 Banana
Ethyl butanoate, C
3H
7COOC
2H
5 Pineapple
Tags
Categories
ScienceDownload
Download Slideshow Get the original presentation fileQuick Actions
Statistics
- Views 301
- Slides 135
- Favorites 1
- Age 496 days
Related Slideshows
23
Earthquakes_Type of Faults_Science G8.pptx
OctabellFabila1
31 views
15
Quiz #1 Science 10 in the first quarter for jhs
HendrixAntonniAmante
30 views
9
Astronomy history from long ago till doday
ssuserbd9abe
29 views
9
Great history of astronomy from long ago till today
ssuserbd9abe
27 views
20
EARTHQUAKE-DRILL.powerpoint.............
chalobrido8
30 views
9
History of astronomy from old times to the present times
ssuserbd9abe
30 views