Question

Given below is a list of compounds:
A) $HCHO$

B) $C{H}_{3}COC{H}_3$
C) $PhCOC{H}_3$

D) $PhCOPh$

The increasing order of the rate of $HCN$ addition to compounds, $A,B,C$ and $D$ is :

• A. $A<B<C<D$
• B. $D<B<C<A$
• C. $D<C<B<A$
• D. $C<D<B<A$

Answer 1

Answer: (C)

$D<C<B<A$

In general, aldehydes are more reactive than ketones.
Among ketones, the one with more phenyl group will be more stabilized and hence, will be less reactive.
Therefore, the correct order of stability is $D<C<B<A$.