Question

Which of the following salt solutions ($0.1M$ each) will have the lowest pH values?

• A. CaCO₃
• B. Ca(OH)₂
• C. CaCl₂
• D. CH₃COONa

Answer 1

The correct option is C

CaCl₂

In $CaC{O}_3$, both the ions $C{a}^{2+}$ and $C{O}_3^{2-}$ are hydrolysed. In $CaC{l}_2$, only $C{a}^{2+}$ ions are hydrolysed. Both $Ca(OH{)}_2$ and $C{H}_{3}COONa$ are alkaline in nature. Hence, the lowest pH will be that of $CaC{l}_2$ solution.