Naming Compounds.ppt-Naming Compounds.ppt

Naming Compounds.ppt

1. Chemistry: Atoms First
Julia Burdge& Jason Overby
Copyright (c) The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Naming Ionic and
Covalent Compounds

2. A compoundis a substance composed of two or more elements
combined in a specific ratio and held together by chemical bonds.
Familiar examples of compounds are water and salt (sodium
chloride).
Compounds5.1

3. Ionic Compounds and Bonding
The resulting electrically neutral compound, sodium chloride, is
represented with the chemical formula NaCl.
The chemical formula, or simply formula, of an ionic compound
denotes the constituent elements and the ratio in which they
combine.

4. A monatomic ion is named by changing the ending of the element’s
name to –ide.
Cl
–
is chlorideO
2–
is oxide
Some metals can form cations of more than one possible charge.
Fe
2+
: ferrous ion [Fe(II)]
Fe
3+
: ferric ion [Fe(III)]
Mn
2+
: manganese(II) ion
Mn
3+
: manganese(III) ion
Mn
4+
: manganese(IV) ion
Naming Ions and Ionic Compounds5.4

5. Naming Ions and Ionic Compounds

6. Naming Ions and Ionic Compounds
Formulas for ionic compounds are generally empirical formulas.
Ionic compounds are electronically neutral.

7. Al
3+
O
2–
Al
2O
3
In order for ionic compounds to be electronically neutral, the sum
of the charges on the cation and anion in each formula must be
zero.
Aluminum oxide:
Sum of charges:2(+3) + 3(–2) = 0
Formulas of Ionic Compounds

8. Formulas of Ionic Compounds

9. Naming Ions and Ionic Compounds
To name ionic compounds:
1) Name the cation
omit the word ion
use a Roman numeral if the cationcan have more than one
charge
2) Name the anion
omit the word ion
Examples:
NaCNsodium cyanide
FeCl
2iron(II) chloride
FeCl
3iron(III) chloride

10. Polyatomic ions consist of a combination of two or more atoms.
Formulas are determined following the same rule as for ionic
compounds containing only monatomic ions: ions must combine in
a ratio that give a neutral formula overall.
Calcium phosphate:
Covalent Bonding in Ionic Species5.7
Ca
2+
PO
4
3–
Ca
3(PO
4)
2
Sum of charges:3(+2) + 2(–3) = 0

11. Covalent Bonding in Ionic Species

12. Covalent Bonding in Ionic Species

13. Worked Example 5.9
StrategyBegin by identifying the cation and anion in each compound, and then
combine the names for each, eliminating the word ion.
Name the following ionic compounds: (a) Fe
2(SO
4)
3, (b) Al(OH)
3, and (c) Hg
2O.
Solution(a) Fe
2(SO
4)
3is iron(III) sulfate.
(b) Al(OH)
3is aluminum hydroxide.
(c) Hg
2O is mercury(I) oxide.
Think About ItBe careful not to confuse the subscript in the formula with the
charge in the metal ion. In part (a), for example, the subscript on Fe is 2, but this
is an iron(III) compound.

14. Covalent Bonding in Ionic Species
Oxoanionsare polyatomic anions that contain one or more oxygen
atoms and one atom (the “central atom”) of another element.
Starting with the oxoanionsthat end in –ate, we can name these
ions as follows:
1)The ion with one moreO atom than the –ateion is called the
per…ateion. Thus, ClO
3
-
is the chlorate ion, so ClO
4
-
is the
perchlorateion.
2)The ion with one lessO atom than the –ateion is called the –ite
ion. Thus, ClO
2
-
is the chlorite ion.
3)The ion with two fewerO atom than the –ateion is called the
hypo…iteion. Thus, ClO
-
is the hypochlorite ion.
At minimum, memorize the oxoanionsthat end in –ateso you can
apply these guidelines when necessary.

15. Covalent Bonding in Ionic Species
perchlorate ClO
4
-
chlorate ClO
3
-
chlorite ClO
2
-
hypochloriteClO
-
nitrate NO
3
-
nitrite NO
2
-
phosphate PO
4
3-
phosphite PO
3
3-
sulfate SO
4
2-
sulfite SO
3
2-

16. Worked Example 5.10
StrategyEach species is either an oxoanion or an oxoacid. Identify the
“reference oxidation” (the one with the –ateending) for each, and apply the rules
to determine appropriate names.
Name the following species: (a) BrO
4
-
, (b) HCO
3
-
, and (c) H
2CO
3.
Solution(a) BrO
4
-
has one more O atom than the bromate ion (BrO
3
-
), so BrO
4
-
is the perbromateion.
(b) CO
3
2-
is the carbonate ion. Because HCO
3
-
has one ionizable hydrogen atom,
it is called the hydrogen carbonate ion.
(c) With two ionizable hydrogen atoms and no charge on the compound, H
2CO
3is
carbonic acid.
Think About ItMake sure that the charges sum to zero in each compound
formula. In part (a), for example, Hg
2+
+ 2Cl
-
= (+2) + 2(-1) = 0; in part (b),
(+2) + 2(-1) = 0; and in part (c), 3(+1) + (-3) = 0.
Think About ItRemembering all these names and formulas is
greatly facilitated by memorizing the common ions that end in –ate.
chlorate ClO
3
-
nitrate
NO
3
-
iodate IO
3
-
carbonate CO
3
2-
bromate BrO
3
-
oxalate
C
2O
4
2-
sulfate SO
4
2-
chromate
CrO
4
2-
phosphate PO
4
3-
permanganate
MnO
4
-

17. Worked Example 5.11
StrategyThe –ousending in the name of an acid indicates that the acid is
derived from an oxoanion ending in –ite. The oxoanion must be sulfite, SO
3
2-
, so
add enough hydrogen ions to make a neutral formula.
Determine the formula of sulfurous acid.
SolutionThe formula of sulfurous acid is H
2SO
3.
Think About ItRemembering all these names and formulas is greatly facilitated
by memorizing the common ions that end in -ate.

18. Hydrates
A hydrateis a compound that has a specific number of water
molecules within its solid structure.
For example, in its normal state, copper(II) sulfate has five water
molecules associated with it.
Systematic name: copper(II) sulfate pentahydrate
Formula: Cu(SO)
4∙ 5H
2O
Some other hydrates are
BaCl
2∙ 2H
2O
LiCl ∙ H
2O
MgSO
4∙ 7H
2O
Sr(NO
3)
2∙ 4H
2O

19. Hydrates
When the water molecules are driven off by heating, the resulting
compound, Cu(SO)
4, is sometimes called anhydrous copper(II)
sulfate.
Anhydrousmeans the compound no longer has water molecules
associated with it.

20. Familiar Inorganic Compounds

21. Covalent Bonding and Molecules

22. A chemical formuladenotes the
composition of the substance.
A molecular formulashows the exact
number of atoms of each element in a
molecule.
Some elements have two or more distinct
forms known as allotropes.
For example, oxygen (O
2) and ozone
(O
3) are allotropes of oxygen.
A structural formulashows not only the
elemental composition, but also the
general arrangements.
Covalent Bonding and Molecules

23. Molecular substances can also be represented using empirical
formulas, the whole-number ratio of elements.
While, the molecular formulas tell us the actual number of atoms (the
trueformula), the empirical formula gives the simplestformula.
Molecular formula: N
2H
4
Empirical formula: NH
2
The molecular and empirical formulas are often the same.
Covalent Bonding and Molecules

24. Covalent Bonding and Molecules

25. Remember thatbinarymolecular compounds are substances that
consist of just two different elements.
Nomenclature:
1) Name the first element that appears in the formula.
2) Name the second element that appears in the formula,
changing its ending to –ide.
Examples:
HCl hydrogen chloride
HI hydrogen iodide
Naming Molecular Compounds5.6

26. Greek prefixes are used to denote the number of atoms of each
element present.
Naming Molecular Compounds

27. The prefix mono-is generally omitted for the first element.
For ease of pronunciation, we usually eliminate the last letter of a
prefix that ends in “o” or “a” when naming an oxide.
Example: N
2O
5is dinitrogen pentoxidenot dinitrogen
pentaoxide
Naming Molecular Compounds

28. Worked Example 5.7
StrategyEach compound will be named using the systematic nomenclature
including, where necessary, appropriate Greek prefixes.
Name the following binary molecular compounds: (a) NF
3and (b) N
2O
4.
Solution(a) nitrogen trifluoride
(b) dinitrogen tetroxide
Think About ItMake sure that the prefixes match the subscripts in the
molecular formulas and that the word oxideis not preceded immediately by an
“a” or an “o”.

29. Worked Example 5.8
StrategyThe formula for each compound will be deduced using the systematic
nomenclature guidelines.
Write the chemical formulas for the following binary molecular compounds:
(a) sulfur tetrafluoride and (b) tetraphosphorus decasulfide.
Solution(a) SF
4
(b) P
4S
10
Think About ItDouble-check that the subscripts in the formulas match the
prefixes in the compound names: (a) 4 = tetra and (b) 4 = tetra and 10 = deca.

30. The names of molecular compounds containing hydrogen do not
usually conform to the systematic nomenclature guidelines.
Many are called by the common, nonsystematic names or by names
that do not indicate explicitly the number of H atoms present.
Examples:
B
2H
6 Diborane
SiH
4 Silane
NH
3 Ammonia
PH
3 Phosphine
H
2O Water
H
2S Hydrogen sulfide
Compounds Containing Hydrogen

31. Compounds Containing Hydrogen
One definition of an acidis a substance that produces hydrogen
ions (H
+
) when dissolved in water.
HCl is an example of a binary compound that is an acid when
dissolved in water.
To name these types of acids:
1) remove the –genending from hydrogen
2) change the –ideending on the second element to –ic.
hydrogenchloride→ hydrochloric acid

32. Compounds Containing Hydrogen
A compound must contain at least one ionizable hydrogen atomto
be an acid upon dissolving.

33. Our nomenclature discussion so far has focused on inorganic
compounds, generally defined as those without carbon.
Organic compoundscontain carbon and hydrogen, sometimes in
combination with other atoms.
Hydrocarbonscontain only carbon and hydrogen.
The simplest hydrocarbons are called alkanes.
Organic Compounds

34. Organic Compounds

35. Organic Compounds

36. Organic Compounds
Many organic compounds contain groups of atoms known as
functional groups, which often determine a molecule’s reactivity.

37. A moleculeis an aggregate of two or more atoms in a
definite arrangement held together by chemical bonds
H
2 H
2O NH
3 CH
4
A diatomic moleculecontains only two atoms
H
2, N
2, O
2, Br
2, HCl, CO
A polyatomic moleculecontains more than two atoms
O
3, H
2O, NH
3, CH
4

38. Writing Chemical Formals
One way to remember these
elements is:
Mr. BrINClHOF
There are 7 elements that occur in nature as a diatomic molecule

39. A monatomic ioncontains only one atom
A polyatomic ioncontains more than one atom
Na
+
, Cl
-
, Ca
2+
, O
2-
, Al
3+
, N
3-
OH
-
, CN
-
, NH
4
+
, NO
3
-

40. 2.5

41. Guidelines for Writing Chemical Formulas
for Binary Compounds
1.Except for Hydrogen, the element farther to the left in the
periodic table appears first. Ie: KCl, PCl
3, Al
2S
3, and Fe
3O
4
2.If hydrogen is present, it appears last except when the other
element is from group 16 or 17. Ie: LiH, NH
3, B
2H
6, CH
4
H
2O, HCl and HI
3.If both elements are from the same group, the lower one
appears first. Ie: SiC and BrF
3

42. A molecular formulashows the exact number of
atoms of each element in the smallest unit of a
substance
An empirical formulashows the simplest
whole-number ratio of the atoms in a substance
H
2OH
2O
molecular empirical
C
6H
12O
6 CH
2O
O
3 O
N
2H
4 NH
2

43. ionic compoundsconsist of a combination of cations
and an anions
•the formula is always the same as the empirical formula
•the sum of the charges on the cation(s) and anion(s) in each
formula unit must equal zero
The ionic compound NaCl

44. Formula of Ionic Compounds
Al
2O
3
2 x +3 = +6 3 x -2 = -6
Al
3+
O
2-
CaBr
2
1 x +2 = +2 2 x -1 = -2
Ca
2+
Br
-
Na
2CO
3
1 x +2 = +2 1 x -2 = -2
Na
+
CO
3
2-

45. M
U
S
T
K
N
O
W
Ion Name (common name) Ion Name (Common name)
NH
4
+
Ammonium CO
3
2-
Carbonate
H
3
O
+
Hydronium HCO
3
-
Hydrogen carbonate
(bicarbonate)
OH
-
Hydroxide SO
3
2-
Sulfite
CN
-
Cyanide HSO
3
-
Hydrogen sulfite
NO
2
-
Nitrite SO
4
2-
Sulfate
NO
3
-
Nitrate HSO
4
-
Hydrogen sulfate
ClO
-
Hypochlorite (often
written OCl
-
)
SCN
-
Thiocyanate
ClO
2
-
Chlorite S
2
O
3
2-
Thiosulfate
ClO
3
-
Chlorate CrO
4
2-
Chromate
ClO
4
-
Perchlorate Cr
2
O
7
2-
Dichromate
MnO
4
-
Permanganate PO
4
3-
Phosphate
CH
3
CO
2
-
Acetate (can be written
C
2H
3O
2
-
)
HPO
4
2-
Hydrogen phosphate
C
2
O
4
2-
Oxalate H
2
PO
4
-
Dihydrogen phospate

46. Recognizing Ionic Compounds
A compound is ionic if it contains a metal from group 1
Or group 2 or one of the polyatomic ions. Binary metal
Oxides and sulfides also have ionic characterFig 2-23
Pg 59
Pure water(left)
and a solution
of sugar(right)
do not conduct
electricity
because they
contain virtually
no ions. A
solution of salt
(center)
conducts
electricity well
because it
contain mobile
cationsand
anions.Courtesy Ken Karp

47. Chemical Nomenclature
•Ionic Compounds
–often a metal + nonmetal
–anion (nonmetal), add “ide” to element name
BaCl
2 barium chloride
K
2O potassium oxide
Mg(OH)
2 magnesium hydroxide
KNO
3 potassium nitrate

48. Cations of Variable Charge
Transition metals such as copper may form cations
Of different charge. This is represented by placing a
Roman numeral after the transition metal in
Parentheses after the name of the metal.
CuO Copper(II) oxide
Cu
2O Copper(I) oxide

49. •Transition metal ionic compounds
–indicate charge on metal with Roman numerals
FeCl
22 Cl
-
-2 so Fe is +2iron(II) chloride
FeCl
33 Cl
-
-3 so Fe is +3iron(III) chloride
Cr
2S
33 S
-2
-6 so Cr is +3 (6/2)chromium(III) sulfide

50. •Molecular compounds
•nonmetals or nonmetals + metalloids
•common names
•H
2O, NH
3, CH
4, C
60
•element further left in periodic table
is 1
st
•element closest to bottom of group is
1
st
•if more than one compound can be
formed from the same elements, use
prefixes to indicate number of each
kind of atom
•last element ends in ide

51. HI hydrogen iodide
NF
3 nitrogen trifluoride
SO
2 sulfur dioxide
N
2Cl
4 dinitrogen tetrachloride
NO
2 nitrogen dioxide
N
2O dinitrogen monoxide
Molecular Compounds
TOXIC!
LaughingGas

52. An acidcan be defined as a substance that yields
hydrogen ions (H
+
) when dissolved in water.
HCl
•Pure substance, hydrogen chloride
•Dissolved in water (H
+
Cl
-
), hydrochloric acid
An oxoacidis an acid that contains hydrogen,
oxygen, and another element.
HNO
3 nitric acid
H
2CO
3 carbonic acid
H
2SO
4 sulfuric acid
HNO
3

53. A basecan be defined as a substance that yields
hydroxide ions (OH
-
) when dissolved in water.
NaOH sodium hydroxide
KOH potassium hydroxide
Ba(OH)
2 barium hydroxide

54. Hydrates
A hydrate is an ionic compound that has water molecules
Incorporated into their solid structures
Writing the formula: name of ionic compound-# H
2OPg 89
The Hydrate of copper
sulfate is the pentahydrate,
and the anhydrous copper
sulfate will absorb water
to form the Hydrate.
CuSO
4
5 H
2
O.
Copper(II)sulfate
.
pentahydrate
Olmsted Williams

55. Writing Chemical Formulas
For non ionic compounds with more than 2 atoms
Write Carbon first
Hydrogen second
All other elements in alphabetical order
4 Hydrogen
2 Carbons
4 oxygens
1 Fluorine
1 Sulfur
C
2H
4FlO
4S
4 Carbons
1 Bromine
8 Hydrogen
1 Chlorine
2 Nitrogen
4 Oxygens
C
4H
8BrClN
2O
4
Let’s try some………………
4 Iodines
6 Carbons
10 Hydrogens
C
6H
10I
4

56. Structural Formulas
for Carbon Containing Compounds
Draw a line to show a connection between all elements in a molecule
Carbon makes 4 connections (this makes them central or inside atoms)
Oxygen and Sulfur make 2
Halogens and Hydrogen make 1 (terminal atoms)
Nitrogen makes 3
Let’s try some…………………
C
2H
5FlO
(This molecule contains
an alcohol (OH)
H-C-C-O-H
Fl
H
H
H
C
4H
7ClN (This molecule contains
An amine, NH
2)
Cl-C-C-C-C-N
HH
H
HH
H
H
H
HH

57. Line Formulas
for Carbon Containing Compounds
All ends and corners represent a Carbon
Hydrogens on Carbons are NOT shown
All other elements and Hydrogens not on a Carbon are shown
Let’s try some…………………
(It always helps to draw the structural formula first)
C
2H
5FlO
(This molecule contains
an alcohol (OH)
H-C-C-O-H
Fl
H
H
H
C
4H
7ClN (This molecule contains
An amine, NH
2)
Cl-C-C-C-C-N
HH
H
HH
H
H
H
HH
F
O H
Cl
N
H
H

58. Naming Carbon Compounds
Prefixes for number of carbons
1Meth-
2Eth-
3Prop-
4But-
5Pent-
6Hex-
7Hept-
8Oxt-
9Non-
10Dec-
If there are only single bonds
The ending is ane
Hydrogens are understood
All other groups attached to a carbon
are listed before the carbon based name
If the compound is circular the
Prefix cyclo is attached
If there is an –OH group attached
The compound ends in ol
Let’s try some problems……………………….