Question

Assertion
When ${H_2}S$ gas is passed into an aqueous solution of $ZnC{l_2}$ , $Z{n^{2 + }}$ ions are completely precipitated as zinc sulphate.
Reason
Zinc sulphide is insoluble in solutions of caustic alkali but dissolves in dilute $HCl$
(A) Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
(B) Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
(C) Assertion is incorrect but Reason is correct
(D) Both Assertion and Reason are correct

Answer 1

Hint: During a reaction, some compounds can exist in the form of a solid, liquid, or gaseous state. The products that turn to solid form after the reaction settles as a precipitate at the bottom of the reaction vessel. The settled precipitate can be physically seen generally and can be separated from the rest of the products.

Complete step by step answer:
The solubility of a compound is defined and measured by the solubility product of the compound. Solubility products can be represented by ${K_{sp}}$. ${K_{sp}}$ of a compound depends on the concentration of the constituents. The higher the solubility product constant the more soluble the compound.${K_{sp}}$ of Zinc Sulphate is very high so is completely predicated In the presence of ammonium hydroxide which is the strong alkali. When ${H_2}S$ it passed in the aqueous solution of $ZnC{l_2}$ , the zinc ions are predicated forming a white precipitate of zinc sulphide

$ZnC{l_2} + HCl\xrightarrow{{}}Zns \downarrow + 2HCl$

Zinc sulphide In insoluble In solutions of sodium hydroxide but on heating with an excess of $NaOH$ , sodium zincate is formed. So we can conclude that the assertion that is given does not mention the alkali ad thus is incorrect while the reason is correct concerning the facts and data are given.

So, the correct answer is Option C.

Note: Solubility is defined as the maximum amount of solute that can be dissolved in a solvent at equilibrium. The solubility product constant gives the equilibrium between the solid and its constituent’s ion in a solution. The solubility product constant is dependent on the activity of the constituents rather than completely depending on only the concentration of the constituents.