Question

why do aldehydes and ketones undergo a number of addition reactions?

Answer 1

Aldehydes and ketones are unsaturated oraganic compounds hence they undergo addition reactions.

Answer 2

Answer: Because of the presence of unsaturation in these two functional groups.

Explanation:

Aldehydes and ketones are two type of functional groups. The compounds of these two functional groups are known as carbonyl compounds. It is denoted as $-C=O$

As, unsaturation is present between carbon and oxygen atoms in carbonyl compounds, therefore addition reactions are more favored.

These two compounds undergo nucleophilic addition reactions because of the difference in electronegativities of carbon and oxygen atoms. The positive charge is present on carbon atom and negative charge on oxygen atoms. Hence, these two compounds, undergo addition reactions readily.