Sure, let's go through the questions step-by-step:
### 7.1.1
Define the term hydrolysis of a salt.
Hydrolysis of a salt is the chemical process in which a salt reacts with water to form an acid and a base. When a salt is dissolved in water, its ions may interact with the water molecules, leading to the dissociation of water molecules into hydrogen ions (H⁺) or hydroxide ions (OH⁻). The nature of the ions produced (acidic or basic) will determine whether the resulting solution is acidic, basic, or neutral.
### 7.1.2
Will the pH of the solution be GREATER THAN, SMALLER THAN, or EQUAL TO 7? Write a relevant equation to support your answer.
Ammonium chloride (NH₄Cl) is a salt derived from a strong acid (hydrochloric acid, HCl) and a weak base (ammonia, NH₃). When ammonium chloride (NH₄Cl) dissolves in water, it dissociates into ammonium ions (NH₄⁺) and chloride ions (Cl⁻).
The ammonium ion (NH₄⁺) can hydrolyze in water:
[tex]\[ \text{NH}_4^+ + \text{H}_2\text{O} \rightleftharpoons \text{NH}_3 + \text{H}_3\text{O}^+ \][/tex]
In this process, the NH₄⁺ ion donates a proton to the water molecule, creating ammonia (NH₃) and a hydronium ion (H₃O⁺). The production of H₃O⁺ ions increases the acidity of the solution. Therefore, the pH of the solution will be SMALLER THAN 7, as the presence of additional H₃O⁺ ions results in an acidic solution.
So, to summarize:
- The pH of the solution will be SMALLER THAN 7.
- The relevant chemical equation is:
[tex]\[ \text{NH}_4^+ + \text{H}_2\text{O} \rightleftharpoons \text{NH}_3 + \text{H}_3\text{O}^+ \][/tex]
