The pH of a solution of 0.10 M `CH_(3)COOH` increases when which of the following substances is added?

Options

A. `NaHSO_(4)`
B. `HClO_(4)`
C. `KNO_(3)`
D. `K_(2)CO_(3)`

Answer

To determine which substance will increase the pH of a 0.10 M solution of acetic acid (CH₃COOH), we need to analyze the options provided and understand how they interact with the acidic solution.

### Step-by-Step Solution:

1. **Understanding pH and Acidity**:
- The pH scale ranges from 0 to 14. A pH less than 7 indicates an acidic solution, while a pH greater than 7 indicates a basic (alkaline) solution. To increase the pH of an acidic solution, we need to add a base.

2. **Identifying the Options**:
- The options given are:
- NaHSO₄ (Sodium bisulfate)
- HClO₄ (Perchloric acid)
- KNO₃ (Potassium nitrate)
- K₂CO₃ (Potassium carbonate)

3. **Analyzing Each Option**:
- **NaHSO₄**: This is a salt formed from a strong acid (H₂SO₄) and a weak base (NaOH). It does not significantly increase pH as it can still contribute to acidity.
- **HClO₄**: This is a strong acid. Adding this will decrease the pH, making the solution more acidic.
- **KNO₃**: This is a salt formed from a strong acid (HNO₃) and a strong base (KOH). It is neutral and does not affect the pH significantly.
- **K₂CO₃**: This is a salt derived from a strong base (KOH) and a weak acid (H₂CO₃). It will dissociate in solution to produce hydroxide ions (OH⁻), which will increase the pH.

4. **Conclusion**:
- Among the options, K₂CO₃ is the only substance that will increase the pH of the 0.10 M CH₃COOH solution because it is a strong base that will neutralize some of the acetic acid, leading to an increase in pH.

### Final Answer:
The pH of a solution of 0.10 M CH₃COOH increases when K₂CO₃ is added.

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