Question

Anhydrous mixture of $KF$and $HF$ contains:
A. ${K^ + },{H^ + },{F^ - }$
B. $K{F^ + },H{F^ - }$
C. $K{H^ + },{F^ - }$
D. ${K^ + },HF_2^ - $

Answer 1

Hint: $KF$ and $HF$ will undergo hydrogen bonding between the fluorine atom of potassium fluoride and hydrogen of hydrogen fluoride due to which we will not get the fluoride ion along with the other products.

Complete step by step answer: $KF$ is known as potassium fluoride. $KF$ is the primary source of fluoride ions for applications in manufacturing and in chemistry. It is in general an alkali halide.
$KF$ is a poisonous compound. It is harmful if inhaled or ingested. It is highly corrosive and can cause severe burns.
$HF$ is hydrogen fluoride. It is a colorless gas and is a principal industrial source of fluorine. Its aqueous solution is known as hydrofluoric acid.
$HF$ is a highly dangerous gas. It can even cause blindness by rapid destruction of the corneas.
The reaction between $KF$ and $HF$ results in the formation of potassium hydrofluoride.
$KF + HF \to KH{F_2}$
The compound can be written as ${K^ + }{\left[ {H{F_2}} \right]^ - }$
The formation of $HF_2^ - $ anion is done by the process of hydrogen bonding.
So, the anhydrous mixture of $KF$and $HF$ will result in the formation of ${K^ + }$ and $HF_2^ - $ ions.
So, the correct answer is “Option D”.

Note: As both $KF$ and $HF$are poisonous and can cause serious effects. So, the careful handling of both should be done. So, the careful handling of both should be done. Moreover, both of them are the primary source of fluoride ion individually but their anhydrous mixture does not produce fluoride ion as a product which is an exception.