Question

What happens to the solubility of a saturated solution of NaCl, when a current of HCl gas is passed through it?

• A. Increases
• B. Decreases
• C. Remains unchanged
• D. Decomposes NaCl

Answer 1

The correct option is B

Decreases

When HCl gas is passed through a saturated NaCl solution, the number of ${\text{Cl}}^{-1}$ ions increases. The increased number of ${\text{Cl}}^{-1}$ interact with ${\text{Na}}^{+1}$ ions to form crystallised NaCl. Thus, the solubility of NaCl decreases and it is recovered in crystalline form. This phenomenon is called "common ion effect".