Question

Which of the following aqueous solutions give white precipitate with perchloric acid?
A. $NaCl$
B. $KCl$
C. $MgC{{l}_{2}}$
D. $FeC{{l}_{3}}$

Answer 1

Hint: Potassium chloride on reaction with perchloric acid produces a white colored precipitate. This white colored precipitate is actually a salt of potassium and chlorine.

Complete Step by Step Answer:
Chlorine is a halogen element.
Perchloric acid on reaction with a potassium salt of chlorine that is potassium chloride produces potassium perchlorate along with a strong acid that is hydrogen chloride or hydrochloric acid. This potassium perchlorate is white in colour and produces white precipitate in this reaction.
The reaction can be given as follows:
$HCl{{O}_{4}}+KCl\to KCl{{O}_{4}}+HCl$

Thus in this reaction one mole of Perchloric acid on reaction with one mole of a potassium salt of chlorine that is potassium chloride produces one mole of a white precipitate that is potassium perchlorate along with one mole of a strong acid that is hydrogen chloride or hydrochloric acid.
Thus the correct option is D.

Note: The major element of potassium chlorate, the white ppt is Chlorine which is a group 17 element. It is also known as halogen element. Perchloric acid is a strong acid of oxo chlorine.