Question

In which of the following solubility of $\mathrm{AgCl}$ will be minimum?

• A. 0.01 M $\mathrm{NaCl}$
• B. 0.01 M ${\mathrm{CaCl}}_2$
• C. 0.01 M ${\mathrm{Na}}_2{\mathrm{SO}}_4$
• D. ${\mathrm{H}}_2\mathrm{O}$

Answer 1

The correct option is B

0.01 M ${\mathrm{CaCl}}_2$

Explanation of correct option:

(B) -

0.01 M ${\mathrm{CaCl}}_2$

Common ion effect: The common ion effect states that the degree of ion association is increased by increasing the concentration of one of the dissociated ions in the solution.

Common ion effect on solubility:

In the presence of a common ion in the solution, the solubility of the solution goes on decreasing.

Adding common ion decrease solubility, as the reaction shifts towards the left to relieve the stress of the excess product. Adding a common ion to a dissociation reaction causes the equilibrium to shift left, towards the reactants, causing precipitation.

Explanation of incorrect options:

(A) -

0.01 M $\mathrm{NaCl}$

Only one number of Chloride ions is present hence solubility greater as compared with calcium chloride.

(C) -

0.01 M ${\mathrm{Na}}_2{\mathrm{SO}}_4$

It does not have a common ion (chloride) and thus $\mathrm{AgCl}$is insoluble in${\mathrm{Na}}_2{\mathrm{SO}}_4$.

(D) -

It does not have a common ion (chloride) and thus $\mathrm{AgCl}$is insoluble in${\mathrm{H}}_2\mathrm{O}$.

Hence option (B) is the correct answer.