When a drop of a solution X is added to the universal indicator, a deep red colour is produced. Which one of the following is this sample?

Options

A. Sodium hydroxide
B. Hydrochloric acid
C. Distilled water
D. Acetic acid

Answer

To determine the identity of solution X based on the color produced when it is added to a universal indicator, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Universal Indicator**:
- A universal indicator is a pH indicator that shows different colors at different pH levels. It can indicate whether a solution is acidic, neutral, or basic.

2. **Identifying Color Correspondence**:
- The color red indicates a strong acid with a pH less than 3.
- Orange to yellow indicates weak acids (pH 3 to 6).
- Green indicates a neutral solution (pH 7).
- Blue indicates weak bases (pH 8 to 11).
- Violet or indigo indicates strong bases (pH 11 to 14).

3. **Analyzing the Given Solutions**:
- **Sodium Hydroxide**: This is a strong base and would produce a violet color with the universal indicator.
- **Hydrochloric Acid (HCl)**: This is a strong acid and would produce a red color with the universal indicator.
- **Water**: This is neutral and would produce a green color with the universal indicator.
- **Acetic Acid**: This is a weak acid and would produce an orange or yellow color with the universal indicator.

4. **Conclusion**:
- Since the question states that the addition of solution X to the universal indicator produces a deep red color, the only solution that fits this description is hydrochloric acid (HCl).

Thus, solution X is **Hydrochloric Acid (HCl)**.