Aromatic Hydrocarbon Flashcards
(33 cards)
Aromatic Hydrocarbons are also known as
Arenes
What are aromatic compounds?
Aromatic compounds are benzene and compounds that resemble benzene in chemical behaviour.
General formula of arenes
CnH2n-6y
where,
n = number of carbons
y= number of rings
Two benzene attached
Napthalene
Three benzene attached in a curved way
Phenanthrene
3 benzene attached
Anthracene
C6H6-COOH
Benzoic acid
C6H6-SO3H
Benzenesulphonic acid
C6H6-C=OH
Benzaldehyde
When the side chain is saturated and has less no of carbon atom in it than the benzene ring, the side chain acts as
Substituent
When saturated side chain has same no of carbon atom as benzene ring
benzene ring win over and the side chain is treated as substituent
When saturated side chain has more no of carbon atoms than benzene ring
benzene acts like a substituents and the word phenyl is used for benzene.
When the side chain is saturated or the side chain has some functional group
benzene behave like a substituent
position 1-2,6
ortho
position 1-3,5
meta
position 1-4
para
The general characteristics of compound to show aromaticity are
- Cyclic
- Each element must have sp2 hybridization and molecule must beplanar
- delocalized pi electrons above and below the plane of the molecule
- flollow Huckel’s Rule
State Huckel’s rule
The compound is aromatic if the molecule contains cyclic cloud of delocalized pi electrons above and below the plane of molecule and pi clouds must contain a total of (4n+2) pi electrons where n= 0,1,2,3,…. only whole no integers
HUckel’s rule of aromaticity is also known as
(4n+2)rule
Benzene was first isolated by
Faraday
The first to suggest a ring structure for benzene was
Kekule
what is resonance?
The phenomenon in which two or more structures can be written for a substance that has identical position of atoms is called resonance.
How is benzene formed from acetylene?
When acetylene is passed through a red hot tube at 873K, it forms benzene.
How is benzene obtained from sodium salt of carboxylic acid?
when sodium benzoate (C6H5CooNa) is heated with sodalime(NaOH), benzene is formed.
