Question

A salt gives white precipitate with barium chloride insoluble in concentrated $HCl$ is:
A.Zinc sulphate
B.Magnesium carbonate
C.Lead chloride
D.Calcium nitrate

Answer 1

Hint:Precipitation is defined as a chemical reaction where two solutions of two ionic substances are mixed together which results in the formation of a precipitate. This process is known as precipitation. In this reaction, a solution having cation is mixed with a solution having anion and forms an insoluble compound.

Complete step-by-step answer:As we have mentioned above that when two soluble salts are mixed together they results in the formation of insoluble solid.
According to the solubility rules, except barium, lead and calcium most of the sulphate salts are soluble and except mercury, silver and calcium most of the chlorides salts are soluble.
In this question, barium chloride is mixed with a salt that gives white precipitate and is insoluble in concentrated hydrochloric acid. Therefore, the salt should be soluble to give out precipitate which is an insoluble solid.
The product formed due to this reaction will be salts of barium, sulphate salts are insoluble and therefore the product can be barium sulphate.
When barium chloride reacts with sulphate ion, it results in the formation of thick white precipitate of barium sulphate. In the above options, the only sulphate ion present is zinc sulphate.
When barium chloride reacts with zinc sulphate, it results in the formation of a white precipitate known as barium sulphate. The zinc sulphate is insoluble in concentrated hydrochloric acid because sulphate ions are weak bases.
Let us see the reaction:
$BaC{{l}_{2}}\left( aq \right)+ZnS{{O}_{4}}\left( aq \right)\to BaS{{O}_{4}}\left( s \right)+ZnCl\left( s \right)$

Therefore, the correct option is A.

Note:It is to note that this precipitation reaction is a double displacement reaction. Barium sulphate is insoluble in water hence it precipitates. Another reason for the formation of precipitate is because of lowering of temperature. This decreases the solubility and hence precipitation occurs. We use precipitation reactions for detecting the presence of particular ions in the solution.