module 6 - carbonyls and carboxylic acids

Question 1

Where is the functional group found in an aldehyde?

Answer 1

at the end of a carbon chain
CHO

Question 2

Where is the functional group on a ketone?

Answer 2

its joined to 2 carbon atoms in the carbon chain

Question 3

Describe the oxidation of aldehydes

Answer 3

aldehydes can be oxidised to carboxylic acids when refluxed with acidified dichromate ions

ketones don’t undergo oxidation reactions

Question 4

describe the nucleophilic addition reactions of the carbonyl group

Answer 4

C=C double bond in alkenes is non-polar whilst the C=O double bond in carbonyl compounds is polar

due to the polarity of the C=O bond, aldehydes and ketones react with some nucleophiles

Reducing an aldehyde:
- aldehydes are reduced to primary alcohols by NaBH4

Reducing a ketone:
- ketones are reduced to secondary alcohols by NaBH4

Question 5

Describe the reaction of carbonyl compounds with HCN

Answer 5

Hydrogen Cynaide adds across the C=O bond of aldehydes and ketones
- HCN is a colourless and poisonous liquid that boils above room temp
sodium cyanide and sulphuric acid are hence used to provide the HCN in the reaction