Question

Which of the following is the distinguishing characteristic between aldehydes and ketones?

a. Ketones contain an oxygen atom, while aldehydes do not.

b. Aldehydes are more substituted versions of ketones.

c. Aldehydes contain an oxygen atom bound directly to a hydrogen atom, while the oxygen atoms in ketones are only bound to carbon atoms.

d. Ketones contain a carbonyl group between two carbons, while the carbonyl group in an aldehyde must be attached to a hydrogen.

Answer 1

Both aldehyde and Ketone contains oxygen atom.

So, a is not correct

b is not correct as it is not saying anything that can distinguish them

Aldehydes contain an oxygen atom bound directly to a hydrogen atom, while the oxygen atoms in ketones are only bound to carbon atoms but same is the case for alcohol and ether.

Alcohol contain an oxygen atom bound directly to a hydrogen atom, while the oxygen atoms in ether are only bound to carbon atoms.

So, c is not correct

d is correct.

In Aldehyde, carbonyl group (C=O) is present between a carbon and a hydrogen.

In Aldehyde, carbonyl group (C=O) is present between 2 carbon atom.

Answer: d

Answer 2

c. Aldehydes contain an oxygen atom bound directly to a hydrogen atom, while the oxygen atoms in ketones are only bound to carbon atoms.

This is the distinguishing characteristic between aldehydes and ketones. In aldehydes, the carbonyl group (C=O) is always at the end of a carbon chain, and it is directly bonded to a hydrogen atom. In contrast, ketones have the carbonyl group located within a carbon chain, and it is bonded to two other carbon atoms. The presence or absence of a hydrogen atom directly bonded to the oxygen atom in the carbonyl group is what separates aldehydes from ketones.