MHTCET 11 Apr 2026 Shift 1 Paper

Concept:$\mathrm{CuSO}_4$ is a salt formed from a strong acid and a weak base, so its aqueous solution is acidic in nature.Explanation:When $\mathrm{CuSO}_4$ is dissolved in water, it dissociates completely into $\mathrm{Cu}^{2+}$ and $\mathrm{SO}_4^{2-}$ ions.This salt is derived from $\mathrm{H}_2\mathrm{SO}_4$ (a strong acid) and $\mathrm{Cu(OH)}_2$ (a weak base).Only the cation $\mathrm{Cu}^{2+}$ undergoes hydrolysis with water, producing $\mathrm{H}^+$ ions:$$\mathrm{Cu}^{2+} + 2\mathrm{H}_2\mathrm{O} \rightleftharpoons \mathrm{Cu(OH)}_2 + 2\mathrm{H}^+$$The release of $\mathrm{H}^+$ ions makes the solution acidic, so its pH becomes less than $7$.Now, checking each option:Option A is incorrect because the anion $\mathrm{SO}_4^{2-}$ does not react with water; the cation undergoes hydrolysis.Option B is incorrect because an acidic solution turns blue litmus red, not red litmus blue.Option C is correct because the pH is indeed less than $7$.Option D is incorrect because hydrolysis of $\mathrm{CuSO}_4$ clearly occurs in water.Answer:Option C is the only correct statement.