A buffer solution can be prepared from a mixture of

Options

A. Sodium acetate and acetic acid in water.
B. Sodium acetat and hydrochloric acid in water.
C. Ammonia and ammonia chloride in water.
D. Ammonia and sodium hydroxide in water.

Explanation

To determine which mixtures can form a buffer solution, we need to understand the definition and requirements for buffer solutions. A buffer solution is typically composed of either:

1. A weak acid and its salt (formed with a strong base).
2. A weak base and its salt (formed with a strong acid).

Now, let's analyze each option provided in the question step by step.

### Step 1: Analyze the first option - Sodium acetate and acetic acid in water.
- **Components**: Sodium acetate (CH₃COONa) is the salt of acetic acid (CH₃COOH), which is a weak acid.
- **Conclusion**: This mixture contains a weak acid (acetic acid) and its salt (sodium acetate), thus it can form a buffer solution.

### Step 2: Analyze the second option - Sodium acetate and hydrochloric acid in water.
- **Components**: Sodium acetate is a salt, and hydrochloric acid (HCl) is a strong acid.
- **Conclusion**: This mixture does not contain a weak acid or a weak base; instead, it has a strong acid. Therefore, it cannot form a buffer solution.

### Step 3: Analyze the third option - Ammonia and ammonium chloride in water.
- **Components**: Ammonia (NH₃) is a weak base, and ammonium chloride (NH₄Cl) is the salt formed from a weak base and a strong acid (HCl).
- **Conclusion**: This mixture contains a weak base (ammonia) and its salt (ammonium chloride), thus it can form a buffer solution.

### Step 4: Analyze the fourth option - Ammonia and sodium hydroxide in water.
- **Components**: Ammonia is a weak base, and sodium hydroxide (NaOH) is a strong base.
- **Conclusion**: This mixture contains two bases (one weak and one strong) and does not meet the criteria for forming a buffer solution.

### Final Conclusion:
Based on the analysis:
- **Correct options for buffer solutions**:
- Option 1: Sodium acetate and acetic acid (Buffer solution)
- Option 3: Ammonia and ammonium chloride (Buffer solution)
- **Incorrect options**:
- Option 2: Sodium acetate and hydrochloric acid (Not a buffer)
- Option 4: Ammonia and sodium hydroxide (Not a buffer)

### Answer:
The buffer solutions can be prepared from:
- Option 1: Sodium acetate and acetic acid in water.
- Option 3: Ammonia and ammonium chloride in water.