Which indicator will produce a pink colour on adding a few drops of sodium hydroxide solution?

Options

A. blue litmus
B. phenolphthalein
C. turmeric paper
D. china rose indicator

Answer

To determine which indicator will produce a pink color when a few drops of sodium hydroxide (NaOH) solution are added, we can analyze the properties of different indicators in relation to basic solutions.

### Step-by-Step Solution:

1. **Identify the Nature of Sodium Hydroxide Solution**:
Sodium hydroxide (NaOH) is a strong base. Therefore, when we add it to a solution, we are working with a basic environment.

2. **List Common Indicators**:
Common indicators include:
- Blue litmus
- Phenolphthalein
- Turmeric
- China rose

3. **Evaluate Each Indicator**:
- **Blue Litmus**:
- In a basic solution, blue litmus remains blue. It does not change color, so it will not produce a pink color.
- **Phenolphthalein**:
- In a basic solution, phenolphthalein turns pink. This is the color change we are looking for.
- **Turmeric**:
- Turmeric paper turns dark red in a basic solution. Thus, it does not produce a pink color.
- **China Rose**:
- China rose indicator gives a green color in a basic solution. This is also not the desired pink color.

4. **Conclusion**:
Based on the evaluations, the only indicator that produces a pink color when sodium hydroxide solution is added is **Phenolphthalein**.

### Final Answer:
The indicator that will produce a pink color on adding a few drops of sodium hydroxide solution is **Phenolphthalein**.