Question

Select correct statement(s) regarding behaviour of $HF$ as non-aqueous solvent:

• A. $HCl$ behaves as an acid and $HF$ as a base.
• B. $HCl{O}_4$ behaves as a base and $HF$ as an acid.
• C. $HN{O}_3$ and $H_{2}S{O}_4$ behaves as base and HF as an acid.
• D. All of the above are correct statements.

Answer 1

The correct option is C $HN{O}_3$ and $H_{2}S{O}_4$ behaves as base and HF as an acid.

HF is a non aqueous solvent.

It undergoes self ionization.

$2HF\rightleftharpoons [H_{2}F{]}^{+}+F^{-}$

Mineral acids suh as $HN{O}_3,HCl$ and $H_{2}S{O}_4$ act as base on dissolution in HF as they accept proton from HF.

$\underset{base}{HN{O}_3}+\underset{acid}{HF}\rightleftharpoons \underset{acid}{H_{2}N{O}_3^{+}}+\underset{base}{F^{-}}$

However, perchloric acid behaves as an acid in liquid HF.

$\underset{acid}{HCl{O}_4}+\underset{base}{HF}\to \underset{base}{Cl{O}_4^{-}}+\underset{acid}{H_2{F}^{+}}$