Question

Assertion :On passing $HCl\left(g\right)$ through a saturated solution of $Ba{Cl}_2$, a white turbidity appears Reason: The common ion effect is responsible for white turbidity

• 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 correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

HCl is a strong electrolyte and completely dissociates in aqueous solution to provide chloride ions.

$HCl\to H^{+}+C{l}^{-}$

The dissociation of salt $BaC{l}_2$ is shown below.

$BaC{l}_2\rightleftharpoons B{a}^{2+}+2C{l}^{-}$

Chloride ions are common ions. Due to the dissociation of HCl, chloride ion concentration increases, which suppresses the ionisation of $BaC{l}_2$. With an increase in chloride ion concentration, the ionic product of $BaC{l}_2$ exceeds its solubility product.

Hence, $BaC{l}_2$ precipitates and white turbidity appears.