Question

Strength of acid-base is influenced by solvent water. Select the correct statement(s) about the leveling effect of water on the strength of acid-base.

• A. $N{H}_2^{-}$ and $H^{-}$ in water show levelling effect and have same base strength.
• B. Acids which are weaker than $H_3{O}^{+}$ are not levelled by water.
• C. Bases which are stronger than $O{H}^{-}$ are levelled by water.
• D. Acids and bases are also leveled in the same characteristic solvents other than water.

Answer 1

Answer: (A), (B), (C), (D)

The correct options are
A $N{H}_2^{-}$ and $H^{-}$ in water show levelling effect and have same base strength.
B Acids which are weaker than $H_3{O}^{+}$ are not levelled by water.
C Bases which are stronger than $O{H}^{-}$ are levelled by water.
D Acids and bases are also leveled in the same characteristic solvents other than water.

The basicity of solvent levels the strength of strong acid. Similarly, the acidity of solvent levels the strength of weak acid.
Thus, acids stronger than $H_3{O}^{+}$ and bases stronger than $O{H}^{-}$ are leveled by water.
Hence, $N{H}_2^{-}$ and $H^{-}$ are leveled by water. They have the same basic strength and their basic strength is similar to that of $O{H}^{-}$ ion. The leveling effect is also observed in solvents other than water. Ammonia is one such solvent which shows leveling effect.

All are correct.