Aromatic Compound's Flashcards
What is the molecular formula of benzene?
C6H6
What is the empirical formula of benzene?
CH
What term is given to any molecule that does not contain a benzene ring?
Aliphatic
What do aromatic compounds contain?
A benzene ring
How many delocalised electrons does benzene contain?
6
What are some problems with the Kekules structure?
Enthalpies of hydrogenation
Reactivity
C-C bond lengths
Benzene does not undergo electrophilic addition reactions with halogens at room temperature like alkenes so what does it undergo?
Benzene will only react with halogens if a catalyst is present. It then undergoes an electrophilic substitution reaction with halogens.
Describe bonding in benzene
Each carbon has 4 outer electrons; one is used to bond to a hydrogen; 2 are used to bond to adjacent carbons; the remaining electron from each carbon form a cloud of delocalised electrons above and below the plane of the ring.
Delocalisation gives rise to extra stability called what?
Delocalisation energy
If alkyl groups with less than 7 carbons, nitro groups and halogens are attached directly to a benzene ring, they are what?
Prefixes to benzene
- put in alphabetical order
- use di, tri and number
If a benzene ring is attached to an alkyl group with a functional group or an alkyl group with 7 or more carbon atoms what prefix is used instead of benzene?
Phenyl
What is the prefix/name when there’s a OH attached directly to ring?
Phenol
What is the prefix/name when there’s a NH2 attached directly to ring?
Phenylamine
What is the prefix/name when there’s a COOH attached directly to ring?
Benzoic acid
What is the prefix/name when there’s a CHO attached directly to ring?
Benzaldehyde
