A certain solution does not change the colour of any indicator. This solution is most likely to be :

Options

A. washing soda solution
B. acidic solution
C. common salt solution
D. Ammonium hydroxide solution

Answer

To determine the type of solution that does not change the color of any indicator, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Indicators**: Indicators are substances that change color in response to the acidity or basicity of a solution. Common indicators include litmus, phenolphthalein, and bromothymol blue.

2. **Identifying Neutral Solutions**: A solution that does not change the color of any indicator is likely a neutral solution. Neutral solutions have a pH of 7 and do not exhibit acidic or basic properties.

3. **Analyzing the Options**:
- **Option 1: Washing Soda Solution (Na2CO3.10H2O)**: This is a basic solution because it is derived from a strong base (NaOH) and a weak acid (H2CO3). Therefore, it will change the color of indicators.
- **Option 2: Common Salt Solution (NaCl)**: This is formed from a strong acid (HCl) and a strong base (NaOH). The resulting solution is neutral and does not change the color of indicators.
- **Option 3: Ammonium Hydroxide Solution (NH4OH)**: This is a weak base and will change the color of indicators, indicating basicity.

4. **Conclusion**: Since the question asks for a solution that does not change the color of any indicator, the only option that fits this criterion is the common salt solution (NaCl).

### Final Answer:
The solution that does not change the color of any indicator is most likely to be **Common Salt Solution (NaCl)**.

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