Question

Aqueous solution of potash alum is:

• A. acidic
• B. basic
• C. neutral
• D. none of the above

Answer 1

The correct option is A acidic

Option $\left(A\right)$ is correct.

Aqueous solution of potash alum is acidic in nature due to cationic hydrolysis.Potash Alum is a salt of potassium and aluminium with sulfate. The acidity comes from $A{l}^{3+}$ ions. When $A{l}^{3+}$ ions are solvated by water molecules, their high charge pulled electron density toward them, making electron density between $O-H$ in solvating water molecules become less. Protons are therefore more likely to be abstracted by water.