Which one of the following has the highest pH?

Options

A. Distilled water
B. 1 M `NH_3`
C. 1 M NaOH
D. Water saturated with chlorine

Answer

To determine which of the given solutions has the highest pH, we will analyze each option based on their acidic or basic nature.

### Step-by-Step Solution:

1. **Understand pH Scale**:
- The pH scale ranges from 0 to 14.
- A pH of 7 is considered neutral (like distilled water).
- A pH less than 7 indicates an acidic solution.
- A pH greater than 7 indicates a basic (alkaline) solution.

2. **Evaluate Each Option**:
- **Option 1: Distilled Water**
- Distilled water is neutral with a pH of approximately 7.

- **Option 2: 1M NH3 (Ammonia)**
- Ammonia is a weak base. The pH of a 1M NH3 solution typically ranges from 7 to 9, depending on its concentration and temperature.

- **Option 3: 1M NaOH (Sodium Hydroxide)**
- Sodium hydroxide is a strong base. A 1M NaOH solution has a very high pH, typically around 13 to 14.

- **Option 4: Water Saturated with Chlorine**
- Chlorine in water can form hydrochloric acid (HCl) and hypochlorous acid (HOCl), making this solution acidic. Therefore, it would have a pH less than 7.

3. **Compare the pH Values**:
- Distilled Water: pH ≈ 7
- 1M NH3: pH ≈ 7 to 9
- 1M NaOH: pH ≈ 13 to 14
- Water Saturated with Chlorine: pH < 7

4. **Conclusion**:
- Among the given options, 1M NaOH has the highest pH, making it the most basic solution.

### Final Answer:
The solution with the highest pH is **1M NaOH**.