Which two sets of reactants best represent the amphoteric character of `Zn(OH)_(2)`?
Set1: `Zn(OH)_(2)(s) and OH^(-)(aq)`
Set 2:`Zn(OH)_(2)(s) and H_(2)O(l)`
Set 3:`Zn(OH)_(2)(s) and H^(+)(aq)`
Set 4 : `Zn(OH)_(2)(s) and NH_(3)(aq)`

Options

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

Explanation

To determine which two sets of reactants best represent the amphoteric character of `Zn(OH)_(2)`, we need to understand what amphoteric means. An amphoteric substance can act both as an acid and as a base.

### Step-by-Step Solution:

1. **Understanding Amphoteric Character**:
- Amphoteric substances can react with both acids and bases. For `Zn(OH)_(2)`, it can donate protons (H⁺) to act as an acid or accept hydroxide ions (OH⁻) to act as a base.

2. **Analyzing the Sets**:
- **Set 1: `Zn(OH)_(2)(s)` and `OH^(-)(aq)`**:
- In this case, `Zn(OH)_(2)` can react with hydroxide ions (OH⁻) to form `Zn(OH)₄²⁻`. Here, `Zn(OH)_(2)` is acting as an acid (donating protons) and `OH⁻` is acting as a base. This demonstrates the amphoteric nature.

- **Set 2: `Zn(OH)_(2)(s)` and `H₂O(l)`**:
- Water does not provide significant H⁺ or OH⁻ ions under normal conditions. Therefore, this set does not effectively demonstrate the amphoteric character of `Zn(OH)_(2)`.

- **Set 3: `Zn(OH)_(2)(s)` and `H^(+)(aq)`**:
- Here, `Zn(OH)_(2)` can react with H⁺ ions to form `Zn²⁺` ions and water. In this reaction, `Zn(OH)_(2)` acts as a base (accepting H⁺) and demonstrates its amphoteric character.

- **Set 4: `Zn(OH)_(2)(s)` and `NH₃(aq)`**:
- Ammonia does not provide H⁺ or OH⁻ ions in a way that would demonstrate the amphoteric properties of `Zn(OH)_(2)`. Thus, this set is not suitable.

3. **Conclusion**:
- The two sets that best represent the amphoteric character of `Zn(OH)_(2)` are:
- **Set 1: `Zn(OH)_(2)(s)` and `OH^(-)(aq)`**
- **Set 3: `Zn(OH)_(2)(s)` and `H^(+)(aq)`**

### Final Answer:
The correct sets are **Set 1 and Set 3**.