Question

A solvent for an insoluble chloride

Answer 1

Answer on Question #79960, Chemistry/ Organic Chemistry

A solvent for an insoluble chloride

Solution

Precipitates like AgCl, AgBr are insoluble in water but are soluble in other solvents like NH₃ due to the process of forming complex ions.

Foe example: examine solubility of AgCl in ammonia

$$\mathrm{AgCl}(s) \leftrightarrow \mathrm{Ag}^{+} + \mathrm{Cl}^{-} \quad \mathrm{K}_{\mathrm{sp}} = 1.8 \times 10^{-10}$$

Formation of complex ion:

$$\mathrm{Ag}^{+} + 2 \mathrm{NH}_{3} \rightarrow \mathrm{Ag}(\mathrm{NH}_{3})_{2}^{+} \quad \mathrm{K}_{\mathrm{f}} = 1.6 \times 10^{7}$$ $$\mathrm{AgCl}(s) + 2 \mathrm{NH}_{3} \leftrightarrow \mathrm{Ag}(\mathrm{NH}_{3})_{2}^{+} + \mathrm{Cl}^{-}$$ $$K_{\mathrm{net}} = K_{\mathrm{sp}} \times K_{\mathrm{f}} = 2.9 \times 10^{-3}$$

$K_{\mathrm{net}} > K_{\mathrm{sp}}$ implies that AgCl is more soluble in aqueous $\mathrm{NH}_3$ than in water.

Answer: ammonia $\mathrm{NH}_{3}$

Answer provided by AssignmentExpert.com