Question

The compound HCl behaves as _____in the reaction,
$HCl+HF\rightleftharpoons H_2^{+}Cl+F^{-}$
A. Strong acid
B. Strong base
C. Weak acid
D. Weak base

Answer 1

Hint:Acids are defined as the compounds which accept electrons or donate protons and bases are defined as the compounds which donate the electrons or accept the protons. In this reaction a redox reaction is taking place.

Complete step by step answer:
The redox reaction is defined as a reaction where oxidation reaction and reduction reaction takes place simultaneously. In Redox reaction, transfer of electrons takes place between the two reactive species to generate a new product.
The oxidation reaction is defined as the reaction where a molecule loses its electron to form the product. In oxidation increase in oxidation state of the atom takes place from the reactant to the product.
The reduction reaction is defined as the reaction where a molecule gains electrons to form the product. In reduction, decrease in oxidation state of the atom takes place from the reactant to the product.
Acids are defined as those species which accept electrons or donate protons and bases are defined as those species which donate the electrons or accept the protons.
In the given reaction a redox reaction is taking place.
The reaction is shown below.
$HCl+HF\rightleftharpoons H_2^{+}Cl+F^{-}$
In this reaction, HCl is accepting protons in the HF medium. Therefore, HCl is acting as a weak base.
Therefore, the correct option is D.

Note:
Hydrochloric acid HCl and hydrogen fluoride both are acidic compounds. As the acidic nature of the compound depends on dissociation of hydrogen ion, the bond length of HF is stronger than HCl therefore the HF will not easily donate its hydrogen ion as compared to HCl. Therefore HCl is more acidic than HF.