Question

Which amongst the following is the strongest acid?

• A. ${\mathrm{CHI}}_3$
• B. ${\mathrm{CHCl}}_3$
• C. ${\mathrm{CHBr}}_3$
• D. $\mathrm{CH}{\left(\mathrm{CN}\right)}_3$

Answer 1

The correct option is D $\mathrm{CH}{\left(\mathrm{CN}\right)}_3$

Acidic strength increases as the stability of the conjugate base increases. Here, the cyano group makes the conjugate base formed (carbanion) stable owing to its electron withdrawing tendency. So, the answer is $CH(CN{)}_3$.