Write equations to show whether the solubility of either of the following is affected by \(\mathrm{pH}\) : (a) \(\mathrm{AgCl} ;\) (b) \(\mathrm{SrCO}_{3}\).

Silver chloride, or \text{AgCl}, is a compound that dissociates into silver ions (\text{Ag}^+) and chloride ions (\text{Cl}^-) when dissolved in water. The solubility product constant, known as \text{K}_{sp}, for \text{AgCl} is expressed as: \[ \text{K}_{sp} = [\text{Ag}^+][\text{Cl}^-] \] \text{Ag}^+ and \text{Cl}^- are the concentrations of the ions in the solution.
One key point to understand is that the solubility of \text{AgCl} is not affected by \text{pH}. This is because \text{Cl}^- does not react with hydrogen ions (\text{H}^+), regardless of the acidity or basicity of the solution.
Therefore, changing the \text{pH} of the solution will not influence the solubility of silver chloride.

Strontium carbonate, or \text{SrCO}_3, dissociates into strontium ions (\text{Sr}^{2+}) and carbonate ions (\text{CO}_3^{2-}) in water. The solubility product constant, \text{K}_{sp}, for \text{SrCO}_3 is represented as: \[ \text{K}_{sp} = [\text{Sr}^{2+}][\text{CO}_3^{2-}] \] In this case, \text{CO}_3^{2-} can indeed react with \text{H}^+. This is a notable difference compared to \text{AgCl}.
When \text{SrCO}_3 is placed in an acidic environment, the carbonate ion (\text{CO}_3^{2-}) reacts with hydrogen ions (\text{H}^+). These reactions are: \[ \text{CO}_3^{2-} + \text{H}^+ \rightarrow \text{HCO}_3^- \] and \[ \text{HCO}_3^- + \text{H}^+ \rightarrow \text{H}_2\text{CO}_3 \] The \text{H}_2\text{CO}_3 then decomposes into carbon dioxide (\text{CO}_2) and water (\text{H}_2\text{O}). These reactions significantly increase the solubility of \text{SrCO}_3 in acidic solutions because they effectively remove \text{CO}_3^{2-} ions from the equilibrium, driving the dissolution of more \text{SrCO}_3 to re-establish equilibrium.

The solubility product constant (\text{K}_{sp}) is a key concept in understanding how salts dissolve. It provides a quantitative measure of a salt's solubility in a solution by representing the product of the concentrations of the ions at equilibrium.
The general form of \text{K}_{sp} for a salt that dissolves to produce cations (\text{M}^m) and anions (\text{A}^n) is: \[ \text{K}_{sp} = [\text{M}^m]^m[\text{A}^n]^n \] where brackets denote the molar concentrations of the ions.
A higher \text{K}_{sp} value indicates higher solubility, while a lower value suggests lower solubility.
Importantly, the \text{K}_{sp} value remains constant for a given salt at a specific temperature.
Understanding \text{K}_{sp} helps predict how various factors, such as \text{pH}, affect the solubility of salts in different scenarios.