NEETChemistryIonic Equilibrium
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): The solubility of sparingly soluble Al(OH) ₃ increases when the pH of the solution is decreased. Reason (R): Addition of H ^+ ions consumes OH ^- ions to form water, shifting the equilibrium Al(OH) ₃(s) Al ³⁺(aq) + 3 OH ^-(aq) in the forward direction. In the light of the above statements, choose t
Options
- ABoth Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A).
- BBoth Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation of Assertion (A).
- CAssertion (A) is correct but Reason (R) is not correct.
- DAssertion (A) is not correct but Reason (R) is correct.
Correct answer
A. Both Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A).
Step-by-step solution
Assertion (A) states that the solubility of Al(OH) ₃ increases when pH is decreased (i.e., in an acidic medium). This is correct because Al(OH) ₃ dissolves in acids. Reason (R) explains this using Le Chatelier's principle. The dissolution equilibrium is Al(OH) ₃(s) Al ³⁺(aq) + 3 OH ^-(aq) . When pH is decreased, the added H ^+ ions react with OH ^- ions to form unionised water. This decreases the concentration of OH ^- in the solution. According to Le Chatelier's principle, the equilibrium shifts in the forward dir