Question

Cyanoanilinium ion $\left(C_6{H}_4\left(CN\right)\stackrel{\oplus }{N}{H}_3\right)$ (I) is a stronger acid than anilinium ion (II) due to:

• A. -I and -R effects of $(-CN)$ group
• B. +I and +R effects of $(-CN)$ group
• C. -I and +R effects of $(-CN)$ group
• D. +I and -R effects of $(-CN)$ group

Answer 1

The correct option is A -I and -R effects of $(-CN)$ group

Cyanide ion has $-Iand-R$ effects. Hence, it destablizes the structure having positively charged nitrogen atom and stabilizes the structure having neutral nitrogen atom. Hence, cyanoanilinium ion is a stronger acid than anilinium ion (II).