CHE11111JR AHC M 01 INTRO(30 Sep 2016).ppt

Jee hydrocarbons ppt for cbse and ice....its about it jee main advanced

1. AROMATIC HYDROCARBONS
AROMATIC HYDROCARBONS

2. AROMATIC HYDROCARBONS

3. AROMATIC HYDROCARBONS
Greekword‘aroma’means
pleasantsmelling.So,
Aromatichydrogencarbons
arealsocalled‘arenes’.

4. AROMATIC HYDROCARBONS
AROMATIC HYDROCARBONS
Benzeneandcompoundsthatresemble
benzeneintheirchemicalbehaviourare
calledasaromaticcompounds.
e.g.
Benzene
Naphthalene
Anthracene
Furan
Thiophene
O
:
:
S
:
:

5. AROMATIC HYDROCARBONS
Benzeneandcompoundsthatresemble
benzeneintheirchemicalbehaviorare
calledasaromaticcompounds.
AROMATIC HYDROCARBONS
e.g.
Caffeine ( )
Methyl salicylate
(PAIN RELIEVINGOINTMENTS)

6. AROMATIC HYDROCARBONS
In1865,GermanchemistFriedrichAugustKekuleproposedthe
structureofbenzene.
Structure of Benzene

7. AROMATIC HYDROCARBONS
Structure of Benzene
Thestructureofbenzeneconsistsofacyclicstructurewith3
conjugateddoublebondswhichissystematicallycalled
1,3,5-cyclohexatriene.
Allthecarbonsinbenzenearesp
2
hybridized.
H
H
H
H
H
H
H
H
H
H
H
H

8. AROMATIC HYDROCARBONS
where, n = 0,1,2,3,4…
Criteria for aromaticity
a)Cyclic
b) Planar (i.e., all atoms should be sp
2
hybridized)
c) Completely Conjugated
d)Huckel’sRule:
Compoundsmustcontain(4n+2)πelectrons

9. AROMATIC HYDROCARBONS
Benzene Pyrrole 1,3-ButadieneCyclobutadiene
Non Cyclic
Planar
Conjugated but
(4n + 2) π e
–
are not
present in 1-3
butadiene
Non Aromatic
Cyclic
Planar
Completely conjugated
(4n + 2 )πe
–
are not
present
Non Aromatic
Cyclic
Planar
Completely conjugated
(4n + 2 )πe
–
n = 1
4(1) + 2 = 6 πe
–
Aromatic
Cyclic
Planar
Completely conjugated
(4n + 2) π e
–
n = 1
(4(1) + 2) πe
–
= 6 πe
–
Aromatic
N
:
H

10. AROMATIC HYDROCARBONS
1.Whichofthefollowingisaromatic?
a)

b)
c)

d)

11. AROMATIC HYDROCARBONS
2.WhichofthefollowingisreferredtoasHuckel’srule?
a) (4n+1) electrons
b) (4n + 4) electrons
c) (4n + 2) electrons
d) None of the above

12. AROMATIC HYDROCARBONS

13. AROMATIC HYDROCARBONS
Benzenoids
Thecompoundscontainoneormorebenzeneringsintheirstructure.
e.g.
Benzene Benzaldehyde
CHO
CLASSIFICATION OF AROMATIC COMPOUNDS

14. AROMATIC HYDROCARBONS
Benzenoids
CLASSIFICATION OF AROMATIC COMPOUND
Non-Benzenoids
Thesecompoundsdonotcontainanybenzeneringintheirstructure.
Furan
O
:
:
Thiophene
S
:
:
Pyridine
:
N
e.g.

15. AROMATIC HYDROCARBONS
Aromatic compoundAliphatic compound
Contains higher %
of carbon.
1. Contain lower % of
carbon.
1.
2. Burns with sooty
flame.
Burns with non-sooty
flame.
2.
Cyclic compound
with alternate single
and double bonds.
3. Open chain
compounds.
3.
Distinguish Between Aromatic and Aliphatic compounds
prefers substitution
reactions.
4.
Alkanes
(Subsitutionreactions)
Alkens& Alkynes
(addition reactions)
4.
% of carbon in Benzene
Total mass of C in C
6H
6
Total mass of C
6H
6
100
=
12 6
12 6 + 6 1
100
72
78
= 100
0.9230 100=
=92.30 %
=
% of carbon in Hexane
Total mass of C in C
6H
14
Total mass of C
6H
14
100
=
12 6
12 6 + 14 1
100
72
86
= 100
0.8372 100=
=83.72 %
=

16. AROMATIC HYDROCARBONS
1.AromaticCompoundsburnwith
a) Sooty Flame
b) Non -Sooty Flame
c) Both a & b
d) None of these

17. AROMATIC HYDROCARBONS
2.Naphthalenebelongstowhichtypeofaromaticcompound?
a) Benzenoid
b) Non-Benzenoid
c) Anti-aromatic
d) All the above

18. AROMATIC HYDROCARBONS
3.Allthecarbonatomsinbenzeneare…
a) sp
3
Hybridised
b) sp
2
Hybridised
c) spHybridised
d) sp
3
d Hybridised

19. AROMATIC HYDROCARBONS
4.Benzenecontains…
a) 8electrons
b) 10electrons
c) 6electrons
d) 2electrons

20. AROMATIC HYDROCARBONS

21. AROMATIC HYDROCARBONS
Monosubstituted benzene can be named by placing the name
of substituent as prefix to benzene.
A) MONOSUBSTITUTED BENZENE
Rule 1 :
H NO
2 Br
Benzene Parent compound
Substituent Prefix to Benzene
Chlorobenzene Nitrobenzene Bromobenzene
Cl H H
NOMENCLATURE OF AROMATIC COMPOUNDS
Benzene,in which only
one H-atom is replaced
by alkyl /functional
group

22. AROMATIC HYDROCARBONS
Rule 2 :The name of benzene derivatives are known by common names
which are accepted by IUPAC.
Phenol
OH CH
3
Toluene
NH
2
Aniline Benzoic acid
COOHH H H H

23. AROMATIC HYDROCARBONS
Ifalkylsubstituentislargerthanbenzene,thenbenzene
becomessubstituentandprefixedas(Phenyl).
Rule 3 :
Phenyl
(C
6H
5 –)
Alkyl group
contains more
than 6 carbons
Linked to
functional
group
Benzene
Benzyl
C
6H
5–CH
2 –

24. AROMATIC HYDROCARBONS
–3–phenyl
CH
3–CH –CH
2–CH
2–NO
2
e.g.
2–Phenyl
CH
3–CH –CH
2–CH
2 –CH
2–CH
2–CH
3
Parent chain of
carbon
i.e., Heptane
Substituent
i.e., phenyl
2 4 5 63 71
Heptane
Parent chain
of carbon
i.e., butane
23 1
butane1–Nitro
4

25. AROMATIC HYDROCARBONS
alcohol
OH
Functional
group (alcohol)
CH
2–CH
2 –CH
2 –Cl
Parent chain of
carbon
i.e., Propane
CH
2–
Benzyl
–3–phenyl
23 1
Propane.1–chloro
e.g.

26. AROMATIC HYDROCARBONS
a) 2-Phenyl 4-nitro butane b) 1-nitro 3-phenyl butane
c) 3-methyl 3-phenyl 1-nitro propaned) All the above
1.TheIUPACnameofthefollowingcompound
CH
3–CH –CH
2–CH
2–NO
2

27. AROMATIC HYDROCARBONS
a) 1-nitro 3-benzene carbaldehydeb) 3-nitro benzene carbaldehyde
c) 3-formyl nitro benzene d) All the above
2.TheIUPACnameofthefollowingcompound
CHO
NO
2

28. AROMATIC HYDROCARBONS

29. AROMATIC HYDROCARBONS
e.g.
Position (1, 4) –para (p –)
Functional Group
1
2 Position (1, 2) –ortho (o –)
Position (1, 3) –meta (m –)
3
4
B) DISUBSTITUTED BENZENE
NOMENCLATURE OF AROMATIC COMPOUNDS
Benzene in which only
two H-atoms are replaced
by alkyl /functional
groups
ISOMERS OF DISUBSTITUTED BENZENE

30. AROMATIC HYDROCARBONS
For same substituents, diwill be used as prefix.
NO
2
NO
2
Cl
Cl
o-dichlorobenzene
(1, 2 –dichlorobenzene) (1, 3 –dinitrobenzene)
1
2
1
3
m-dinitrobenzene
Rule 1 :

31. AROMATIC HYDROCARBONS
For different substituents, they can be numberedand enteredin
alphabetical order.
I
Br
p-Bromoiodobenzene
(1-Bromo-4-Iodobenzene)
Rule 2 :
1
2
3
4
Incorrect
way of
numbering
1
2
3
4
correct way
of numbering
m-chloronitrobenzene
(1-Chloro-3-Nitrobenzene)
Cl
NO
2
1
2
3
correct way
of numbering
1
2
3
Incorrect
way of
numbering

32. AROMATIC HYDROCARBONS
Ifoneofthetwogroupsisgivenspecialnametothemolecule,
thecompoundisnamedasthederivativeofthespecial
compound.
NH
2
Cl
o-Chloroaniline
1
2
(2-Chloroaniline)
Rule 3 :

33. AROMATIC HYDROCARBONS
CH
3
NO
2
m-Nitro toluene
Rule 3 :
1
2
3
(3-Nitrotoluene)
Ifoneofthetwogroupsisgivenspecialnametothemolecule,
thecompoundisnamedasthederivativeofthespecial
compound.
OH
Br
p-Bromophenol
(4-Bromophenol)
1
2
3
4

34. AROMATIC HYDROCARBONS
Ifoneofthegroups,whichgivesaspecialnametothe
compoundispresent,thespecialgroupisconsideredin
position1.
Rule 4 :
NO
2
OH
Cl
CH
3
C
2H
5
NH
2
1+2+36=
1+5+612=
2
3
4
1
2
3
4
5
6
5
1
6
(3–Ethyl–2–methyl aniline)
1+2+47=
1+4+611=
2
35
6
4
11
2
3
4
5
6
(2–Chloro–4–nitro phenol)
Lowest combination Lowest combination
Highest combination
It follows lowest
sum rule

35. AROMATIC HYDROCARBONS
Ifmorethantwogroupsareattachedtothedirectionof
numbering,itshouldbesuchthatitgiveslowestcombination
ofnumbers.
Rule 5:
Br
Br
Br
1, 2, 4-Tribromobenzene
1
2
3
4
1+2+47=
Lowest combination
1
2
3
4
5
6
1+4+611=
Highest combination
Br
CH
3
CH
3
1
2
3
4
1+2+47=
Lowest combination
1
2
3
4
5
6
1+4+611=
Highest combination
4–Bromo–1, 2–dimethyl benzene
5
6
5
6

36. AROMATIC HYDROCARBONS
1.Whichofthefollowingis2,4,6-Trinitrotoluene?
CH
3
NO
2
O
2N
NO
2
a)
CH
3
NO
2
NO
2
NO
2
b)
CH
3
NO
2
O
2N
NO
2
c)
CH
3
NO
2
NO
2
d)

37. AROMATIC HYDROCARBONS
2. The structure of Aniline is…
b)
c) d)
a)
OH NH
2
OCH
3 CHO

38. AROMATIC HYDROCARBONS
3. The correct structure of m-dinitrobenzene is…
b)
c) d)
a)
None of these
NO
2
NO
2
NO
2
NO
2
NO
2
NO
2

39. AROMATIC HYDROCARBONS
4. Name of the compound is…
COOH
b)
c) d)
a)
b and c
Acetophenone Benzaldehyde
Benzoic acid

40. AROMATIC HYDROCARBONS
Thank you…