Chapter 20, Problem 49A

Interpretation Introduction

Interpretation:

The structural feature which distinguishes aldehydes and ketones is to be written.

Concept introduction:

Both aldehydes and ketones are oxygen-containing functional groups.

Answer to Problem 49A

Aldehydes contain one alkyl chain attached to the carbonyl group while ketones contain two alkyl chains attached to the carbonyl group.

Explanation of Solution

Aldehydes have a functional group -CHO and ketones have −CO-. So in both, the common group is carbonyl group.

The structures are represented as follows:

  

In aldehydes, the carbonyl is attached to hydrogen from one side and the other side can be hydrogen or alkyl chain. But in ketones, the carbonyl is attached to two alkyl groups.

Aldehyde functional group is always at the end of the carbon chain but the ketonic group is never attached at the end of the carbon chain.

Conclusion

Thus, aldehydes and ketones contain carbonyl group which makes both very much similar in reactivity and difference in alkyl groups, due to which there are some changes in physical properties.