Order of the base strength of the compounds

Question

Order of the base strength of the compounds (A)  iv > ii > i > iii  (B)  iii > ii > iv > i  (C)  ii > iii > iv > i  (D)  ii > iii > i > iv

Tardigrade Admin · Accepted Answer

As the electronegativity of electron donating atom decreases, base strength increases.
The order of electronegativity is

C < N < O

But

C H_{3} CO O^{-}

and

C_{6} H_{5} O^{-}

both have

O

as donor atom, thus their basicity is decided by resonance.

C H_{3} CO O^{-}

being more resonance stabilised, is less basic. Thus, the order of base strength of the given compounds is

Q. Order of the base strength of the compounds