Question

On passing a current of HCl gas in a saturated solution of NaCl, the solubility of NaCl will:

• 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 solution of NaCl, the number of $C{l}^{-}$ ions increases. The increased number of $C{l}^{-}$ interact with $N{a}^{+}$ 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".