For a series of indicators, the colour and `pH` range over which colour change takes place are as follows:
`{:("Indicator",,"Colour change over pH range"),(U,,"Yellow to blue pH 0.0 to 1.6"),(V,,"Red to yellow pH 2.8 to 4.1"),(W,,"Red to yellow pH 4.2 to 5.8"),(X,,"Yellow to blue pH 6.0 to 7.7"),(Y,,"Colourless to red pH 8.2 to 10.0"):}`
Which of the following statements is correct ?

Options

A. Indicator `V` could be used to find the equivalence point for `0.01M` acetic and `0.1M` ammonium hydroxide (ammonia solution) titration.
B. Indicator `Y` could be used to distinguish between `0.1M HCI` and `0.01M NaOH` solutions in water.
C. Indicator `X` could be used to distinguish between solution of ammonium chloride and sodium acetate.
D. Indicator `W` could be suitable for use in determining the concentration of acetic acid in vinegar by base titration.

Explanation

To solve the question regarding the indicators and their pH ranges, we need to analyze each statement based on the information provided about the indicators U, V, W, X, and Y.

### Step-by-Step Solution:

1. **Understand the Indicators and Their pH Ranges**:
- Indicator U: Yellow to blue, pH 0.0 to 1.6
- Indicator V: Red to yellow, pH 2.8 to 4.1
- Indicator W: Red to yellow, pH 4.2 to 5.8
- Indicator X: Yellow to blue, pH 6.0 to 7.7
- Indicator Y: Colourless to red, pH 8.2 to 10.0

2. **Analyze Each Statement**:
- **Statement A**: Indicator V can be used to find the equivalence point of 0.2 molar acetic acid and 0.1 molar ammonium hydroxide solution.
- **Analysis**: The equivalence point of a weak acid (acetic acid) and weak base (ammonium hydroxide) is typically around pH 6-7.5. Indicator V (pH 2.8 to 4.1) is not suitable. **False**.

- **Statement B**: Indicator Y could be used to distinguish between HCl and NaOH solution in water.
- **Analysis**: Indicator Y (colourless to red, pH 8.2 to 10.0) is phenolphthalein, which turns pink in basic solutions (like NaOH) and remains colourless in acidic solutions (like HCl). **True**.

- **Statement C**: Indicator X could be used to distinguish between solutions of ammonium chloride and sodium acetate.
- **Analysis**: Ammonium chloride (strong acid, weak base) and sodium acetate (weak acid) will have similar pH ranges. Indicator X (pH 6.0 to 7.7) is not suitable for distinguishing between them. **False**.

- **Statement D**: Indicator W could be suitable for determining the concentration of acetic acid in vinegar by base titration.
- **Analysis**: For titrating acetic acid, we need an indicator that changes color around pH 7-10. Indicator W (pH 4.2 to 5.8) is not suitable for this purpose. **False**.

3. **Conclusion**:
- The only correct statement is **B**: Indicator Y could be used to distinguish between HCl and NaOH solution in water.

### Final Answer:
The correct statement is **B**.