A is an aqueous solution of Acid and B is an aqueous solution of base. These are diluted separately. Then

Options

A. pH of A increases while that of B decreases till neutral
B. pH of B deceases while that of A increases till neutral
C. pH of A and B decreases
D. pH of A and B increases

Explanation

To solve the question regarding the effect of diluting an aqueous solution of acid (A) and an aqueous solution of base (B) on their pH levels, we can follow these steps:

### Step-by-Step Solution:

1. **Understand pH Scale**:
- The pH scale ranges from 0 to 14. A pH less than 7 indicates an acidic solution, a pH of 7 indicates a neutral solution, and a pH greater than 7 indicates a basic solution.

2. **Dilution of Acid (A)**:
- When an acid is diluted with water, the concentration of hydrogen ions (H⁺) decreases. This is because dilution involves adding more solvent (water), which increases the volume of the solution while the amount of acid remains the same.
- As the concentration of H⁺ ions decreases, the pH of the solution increases. This means that the solution becomes less acidic and moves towards neutral.

3. **Dilution of Base (B)**:
- Similarly, when a base is diluted with water, the concentration of hydroxide ions (OH⁻) decreases. Again, this is due to the addition of water, which increases the volume of the solution.
- As the concentration of OH⁻ ions decreases, the pH of the solution also decreases. This means that the solution becomes less basic and moves towards neutral.

4. **Comparing Changes in pH**:
- For the acid (A), the pH increases as it is diluted, moving towards neutral.
- For the base (B), the pH decreases as it is diluted, also moving towards neutral.
- Therefore, both solutions will approach a neutral pH of 7 as they are diluted.

5. **Conclusion**:
- The pH of solution A (acid) will increase, and the pH of solution B (base) will decrease until both reach a neutral state.

### Final Answer:
When both solutions A (acid) and B (base) are diluted separately, the pH of A will increase and the pH of B will decrease until they both approach a neutral pH.