Question

Select correct statement $\left( s \right)$ regarding behavior of $H\,F$ as non-aqueous solvent.
(A) $HCl$ behaves as an acid and $H\,F$ as a base
(B) $HCl{O_4}$ behaves as a base and $H\,F$ as an acid
(C) $HN{O_3}$ and ${H_2}S{O_4}$ behaves as base and $H\,F$ as an acid
(D) All of the above are correct statement

Answer 1

Hint:
$H\,F$ is used as a non-aqueous solvent because it undergoes self-ionization as
$2H\,F \rightleftharpoons \left[ {{H_2}F} \right] + {F^ - }$ . When hydrogen fluoride is dissolved in water, it may be called hydrofluoric acid. Hydrogen fluoride is released when other fluoride-containing compounds are combined with water.

Complete step by step answer:
$H\,F$ is hydrogen fluoride. It is a colourless gas or liquid and is generally a principal source of fluorine.
$H\,F$ is known to be a very good solvent. Due to the ability of $H\,F$ to participate in hydrogen bonding the proteins and carbohydrates dissolve in $H\,F$ and can be recovered from it.
$H\,F$, hydrogen fluoride undergoes self-ionization the reaction equation is:
$2H\,F \rightleftharpoons \left[ {{H_2}F} \right] + {F^ - }$
The mineral acids such as $HN{O_3}$(nitric acid), $HCl$(hydrochloric acid) and ${H_2}S{O_4}$ (sulphuric acid) acts as a base when are dissolved in $H\,F$. The reason behind is that these mineral acids accept protons from $H\,F$.
$HN{O_3} + HF \rightleftharpoons {H_2}NO_3^ + + {F^ - }$
Perchloric acid having chemical formula as $HCl{O_4}$ acts as an acid only in liquid $H\,F$.
$HCl{O_4} + HF \rightleftharpoons ClO_4^ - + {H_2}{F^ + }$
Therefore, only option C is correct.

Additional information: When $H\,F$ comes in contact with moisture, including tissue, hydrogen fluoride immediately converts into hydrofluoric acid and is highly corrosive and toxic. It can cause blindness by rapid destruction of corneas. Breathing in $H\,F$ can even cause death only in high levels consumption of $H\,F$ during breathing. Moreover, hydrogen fluoride is used to make refrigerants, herbicides, pharmaceuticals, fluorescent light bulbs and many electrical components.

Note:$H\,F$ acts as a non-aqueous solvent only because it is self-ionizing. Moreover, $H\,F$ needs much care and conscious handling as it is highly corrosive when it comes in contact with moisture. Fingertip injuries from hydrogen fluoride may result in persistent pain or even bone loss. It can cause chronic lung disease, skin damage and permanent visual defects.