Which of the following salts are acidic in aqueous solutions?

Options

A. `(NH_(4))_(2)SO_(4)`
B. `NaHCO_(3)`
C. `CuSO_(4)`
D. `AgNO_(3)`

Answer

To determine which of the following salts are acidic in aqueous solutions, we need to analyze the nature of the acids and bases from which the salts are derived. A salt is considered acidic if it is formed from a strong acid and a weak base. The resulting solution will have a pH of less than 7.

### Step-by-Step Solution:

1. **Identify the Salts:**
We need to analyze the given salts to determine their acidic or basic nature in aqueous solutions.

2. **Option 1: NH4O2SO4 (Ammonium Sulfate)**
- When dissolved in water, it dissociates into NH4⁺ and SO4²⁻ ions.
- NH4⁺ (ammonium ion) is derived from a weak base (NH3) and a strong acid (H2SO4).
- Since it comes from a strong acid and a weak base, the solution will be acidic (pH < 7).

3. **Option 2: NaHCO3 (Sodium Bicarbonate)**
- When dissolved in water, it dissociates into Na⁺ and HCO3⁻ ions.
- Na⁺ is from a strong base (NaOH) and HCO3⁻ is from a weak acid (H2CO3).
- This combination results in a basic solution (pH > 7).

4. **Option 3: CuSO4 (Copper(II) Sulfate)**
- When dissolved in water, it dissociates into Cu²⁺ and SO4²⁻ ions.
- Cu²⁺ is derived from a weak base (Cu(OH)2) and a strong acid (H2SO4).
- Therefore, the solution will be acidic (pH < 7).

5. **Option 4: AgNO3 (Silver Nitrate)**
- When dissolved in water, it dissociates into Ag⁺ and NO3⁻ ions.
- Ag⁺ is derived from a weak base (AgOH) and a strong acid (HNO3).
- This results in an acidic solution (pH < 7).

### Conclusion:
The salts that are acidic in aqueous solutions are:
- **Option 1: NH4O2SO4 (Ammonium Sulfate)**
- **Option 3: CuSO4 (Copper(II) Sulfate)**
- **Option 4: AgNO3 (Silver Nitrate)**

### Final Answer:
The acidic salts in aqueous solutions are **Option 1, Option 3, and Option 4**.

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