Question

In the preparation of fluorine, $HF$ is not used because?
A. It is a liquid
B. It is a good conductor of electricity
C. It is not an electrolyte it gives different products
D. It is less reactive

Answer 1

To solve the question, we should know about the basic preparation of fluorine $({F_2})$. There are some characteristics of the reactants and conditions for the preparation of fluorine. So we will observe the characteristics of $HF$ and the condition required for the preparation of fluorine.

Complete step by step answer:
First, we will understand the basic preparation of elemental fluorine. One of the best methods of preparation of elemental fluorine is Electrolytic oxidation. Electrolytic oxidation is a process in which an electric current is passed through a substance to bring a chemical change.
Elemental fluorine $({F_2})$ is the least reactive. To isolate fluorine we use the Whytlaw-Gray method. In this method electrolysis of fused electrolyte potassium hydrogen fluoride $(KH{F_2})$ is carried out in presence of an electric current. Here electrolyte potassium hydrogen fluoride $(KH{F_2})$ is fused which gives cation as $({K^ + } + {H^ + })$ an anion as $({F^ - })$ and when these products of fusion are processed under electrolysis we get the products of the reactions at electrodes cathode and anode. The electrolysis products are given as:
$KH{F_2}\xrightarrow{{Fusion}}{K^ + } + {H^ + } + 2{F^ - }$
At cathode: $2{H^ + } + 2{e^ - } \to {H_2}$
At anode: $2{F^ - } \to {F_2} + 2{e^ - }$
Here electrolyte potassium hydrogen fluoride $(KH{F_2})$ is used instead of hydrogen fluoride $HF$because potassium hydrogen fluoride $(KH{F_2})$ is a good conductor of electricity as it conducts electricity. Potassium hydrogen fluoride $(KH{F_2})$ is a strong electrolyte and gives the required products. As we know that hydrogen fluoride $HF$ is not an electrolyte it gives different products.

So, the correct answer is Option C.

Note: Hydrogen fluoride is a colorless gas or a fuming liquid. The requirement for the preparation is the presence of a strong electrolyte which means a solution that completely ionizes or dissociates in a solution. Some of the strong electrolytes are $HCl,HI,HBr,HN{O_3}$.