Explain with equations and calculations, when necessary, whether an aqueous solution of each of these salts is acidic, basic, or neutral: (a) \(\mathrm{Pb}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2} ;\) (b) \(\mathrm{Cr}\left(\mathrm{NO}_{2}\right)_{3}:\) (c) CsI.

Salt hydrolysis refers to the reaction of salt ions with water to form an acidic or basic solution. When a salt dissolves in water, it dissociates into its constituent ions. These ions can sometimes react with water, altering the solution's pH.
For example, consider the salt \(\text{Pb(CH}_3\text{COO})_2\). When it dissolves, it produces \(\text{Pb}^{2+}\) and \(\text{CH}_3\text{COO}^{-}\) ions. The \(\text{Pb}^{2+}\) ion is a relatively strong Lewis acid and can react with water molecules:
\[\text{Pb}^{2+} + 2\text{H}_2\text{O} \rightarrow \text{Pb(OH)}_2 + 2\text{H}^+\]
This reaction releases \(\text{H}^+\) ions into the solution, leading to an acidic environment.
Understanding whether ions will hydrolyze is crucial for predicting the pH of the solution formed.

Aqueous solutions are solutions where water is the solvent. When a salt dissolves in water, it breaks apart into its ions. This dissociation process is fundamental to understanding the behavior of salts in water.
Let's take the salt \(\text{Cr(NO}_2\text{)}_3\) as an example. In water, it dissociates into \(\text{Cr}^{3+}\) and \(\text{NO}_2^{-}\) ions. These ions can influence the water's pH based on their interaction with water molecules.

For instance, \(\text{Cr}^{3+}\) can react with water to produce an acidic solution:
\[\text{Cr}^{3+} + 3\text{H}_2\text{O} \rightarrow \text{[Cr(H}_2\text{O)}_6]^{3+} \rightarrow \text{[Cr(H}_2\text{O)}_5\text{OH]}^{2+} + \text{H}^+\]
Thus, the understanding of aqueous solutions is essential in predicting the acidic or basic nature of salts.

Determining the pH of a solution involves understanding the concentration of hydrogen ions (\(\text{H}^+\)) it contains. The pH scale ranges from 0 to 14, where solutions with a pH < 7 are acidic, pH = 7 are neutral, and pH > 7 are basic.
In the case of \(\text{CsI}\), when it dissociates in water, it produces \(\text{Cs}^+\) and \(\text{I}^-\) ions. Neither of these ions reacts with water in a way that changes the \(\text{H}^+\) concentration, so the solution remains neutral (pH = 7).

In contrast, both \(\text{Pb(CH}_3\text{COO})_2\) and \(\text{Cr(NO}_2\text{)}_3\) result in solutions where the concentration of \(\text{H}^+\) increases, making the solutions acidic. Thus, understanding the dissociation and possible hydrolysis reactions of salt ions is key to pH determination.

Chemical reactions are processes where substances interact to form new products. These reactions are fundamental to the study of salts in aqueous solutions, which often undergo hydrolysis.
In the dissociation of salts like \(\text{Pb(CH}_3\text{COO})_2\), the reaction can be illustrated as:
\[\text{Pb}^{2+} + 2\text{H}_2\text{O} \rightarrow \text{Pb(OH)}_2 + 2\text{H}^+\]
Here, the \(\text{Pb}^{2+}\) ions react with water, leading to the formation of new products including \(\text{H}^+\) ions, which makes the solution acidic.

For a non-reactive salt like \(\text{CsI}\), the dissociation does not result in any significant interaction with water. The ions remain separate without forming any new products that would alter the pH:
\[\text{CsI} \rightarrow \text{Cs}^+ + \text{I}^-\]
This highlights the importance of understanding chemical reactions for predicting the properties of salt solutions.