Q. The most reactive to nucleophilic attack at the carbonyl group is

 1796  184 AMUAMU 2018Aldehydes Ketones and Carboxylic Acids Report Error

Solution:

The case with which a nucleophile attacks the carbonyl group depends upon the electron deficiency, i.e. the magnitude of positive charge on carbonyl group carbon. Since, among all the groups attached
image
has maximum electron withdrawing effect, electron deficiency will be maximum at carbonyl carbon of acetyl chloride. Hence, acetyl chloride, i.e.
image is most reactive to nucleophilic attack at carbonyl group