Which of the following can not function as a buffer solution under any condition ?

Options

A. NaCl and NaOH
B. NaOH and `NH_(4)OH`
C. `CH_(3)COONa ` and HCl
D. Borax and boric acid

Answer

To determine which of the given combinations cannot function as a buffer solution under any condition, we need to understand what constitutes a buffer solution.

### Step-by-Step Solution:

1. **Definition of Buffer Solutions**:
- Buffer solutions are those that resist changes in pH upon the addition of small amounts of acid or base. They can be either acidic or basic buffers.

2. **Types of Buffers**:
- **Acidic Buffer**: Formed by a weak acid and its conjugate base (salt).
- **Basic Buffer**: Formed by a weak base and its conjugate acid (salt).

3. **Analyzing the Options**:
- **Option 1: NaOH and NaCl**:
- NaOH is a strong base, and NaCl is a salt formed from a strong acid (HCl) and a strong base (NaOH). This combination cannot form a buffer because it lacks a weak acid or weak base.
- **Option 2: NaOH and NH4OH**:
- NH4OH is a weak base, but NaOH is a strong base. This combination does not provide a conjugate acid to form a buffer solution.
- **Option 3: CH3COONa and HCl**:
- CH3COONa is a salt derived from acetic acid (a weak acid) and NaOH (a strong base). HCl is a strong acid. This combination cannot form a buffer because it lacks the weak acid needed to balance the strong acid.
- **Option 4: Boric acid and Borax**:
- Boric acid (H3BO3) is a weak acid, and borax (Na2B4O5(OH)4·8H2O) is a salt formed from this weak acid and a strong base. This combination can function as an acidic buffer.

4. **Conclusion**:
- The combinations that cannot function as buffer solutions under any condition are:
- **NaOH and NaCl**
- **NaOH and NH4OH**
- **CH3COONa and HCl**

Thus, the answer to the question is that options 1, 2, and 3 cannot function as buffer solutions under any condition.