Question

The strongest Bronsted base among the following ions is

• A. $CH _{3} O ^{-}$
• B. $C _{2} H _{5} O ^{-}$
• C. $\left( CH _{3}\right)_{2} CHO ^{-}$
• D. $\left( CH _{3}\right)_{3} CO ^{-}$

Answer 1

Answer: (D)

The corresponding acids are
(a) $CH _{3} OH$
(b) $C _{2} H _{5} OH$
(c) $\left( CH _{3}\right)_{2} CHOH$
(d) $\left( CH _{3}\right)_{3} COH$.
Among $1^{\circ}, 2^{\circ}$ and $3^{\circ}$ alcohols, the order of acidity is $1^{\circ}>2^{\circ}>3^{\circ}$. A weak acid has strong conjugate base.
Therefore (d) is strongest conjugate base.