Question

The increasing order of the rate of $HCN$ addition to compounds I - IV is:
I. $HCHO$
II. $C{H}_{3}COC{H}_3$
III. $PhCOC{H}_3$
IV. $PhCOPh$

• A. I < II < III < IV
• B. IV < II < III < I
• C. IV < III < II < I
• D. III < IV < II < I

Answer 1

The correct option is C IV < III < II < I

Addition of $HCN$ is a nucleophillic addition reaction. Greater the electron deficiency of carbonyl group, higher is the rate of reaction.