Question

Rank in the order of increasing acidic strength:

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

Answer 1

The correct option is C $B<A<C$

The greater $I$ effect is favorable or greater acidic strength. The $-I$ effect of aldehyde group is greater than the ester group. Due to this $C$ will be most acidic. In $A$ and $B$, $B$ will be less acidic as it has $-I$ effect sort of localized due to ester group being on a single carbon. In $A$ it is more delocalized is not effective on more by adjacent carbons.

Hence, the required order is- $B<A<C$.