Consider the following salts. Which one(s) when dissolved in water will produce an acidic solution?
1. `NH_(4)Cl` , 2. `KHSO_(4)` , 3. `NaCN` , 4. `KNO_(3)`

Options

A. 2 and 3
B. 1 and 2
C. only 3
D. 2 and 4

Answer

To determine which of the given salts will produce an acidic solution when dissolved in water, we need to analyze each salt based on the strength of its constituent acid and base.

### Step-by-Step Solution:

1. **Identify the Salts and Their Components:**
- **NH₄Cl:** This salt is formed from NH₄OH (ammonium hydroxide) and HCl (hydrochloric acid).
- **KHSO₄:** This salt is formed from KOH (potassium hydroxide) and H₂SO₄ (sulfuric acid).
- **NaCN:** This salt is formed from NaOH (sodium hydroxide) and HCN (hydrocyanic acid).
- **KNO₃:** This salt is formed from KOH (potassium hydroxide) and HNO₃ (nitric acid).

2. **Analyze Each Salt:**
- **NH₄Cl:**
- NH₄⁺ (from NH₄OH) is a weak base, and Cl⁻ (from HCl) is a neutral ion.
- Since NH₄⁺ can donate protons (H⁺), the solution will be acidic.
- **Conclusion:** Produces an acidic solution.

- **KHSO₄:**
- K⁺ (from KOH) is a neutral ion, and HSO₄⁻ (from H₂SO₄) can donate protons.
- HSO₄⁻ is a weak base and can also act as a weak acid, leading to an excess of H⁺ in solution.
- **Conclusion:** Produces an acidic solution.

- **NaCN:**
- Na⁺ (from NaOH) is a neutral ion, and CN⁻ (from HCN) is a weak base.
- Since CN⁻ can accept protons, the solution will be basic.
- **Conclusion:** Does not produce an acidic solution.

- **KNO₃:**
- K⁺ (from KOH) is a neutral ion, and NO₃⁻ (from HNO₃) is also a neutral ion.
- Both components are from strong acids and bases, leading to a neutral solution.
- **Conclusion:** Does not produce an acidic solution.

3. **Final Answer:**
- The salts that produce an acidic solution when dissolved in water are **NH₄Cl** and **KHSO₄**.

### Summary:
- **Acidic Solutions:** NH₄Cl, KHSO₄
- **Non-Acidic Solutions:** NaCN, KNO₃