Question

Identify the strongest and the weakest bases among the following.

The strongest acid and the weakest base respectively are:

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

Answer 1

The correct option is C I and IV

(I) is the strongest acid because $N$ is already protonated and will easily loose $H^{+}$ to become neutral.
(IV) is the weakest base as lone pair of $N$ is in conjugation with benzene ring as well as electron withdrawing $CO$ group.