An indicator '`X`' is used for studying the effect of variation in concentration of iodide on the rate of reaction of iodide ion with `H_(2)O_(2)` at room temp.The indicator '`X`' forms blue colored complex with compound 'A' present in the solution.The indicator '`X`' and compound 'A' respectively are

Options

A. Methyl orange and iodine
B. Starch and iodine
C. Methyl orange and `H_(2)O_(2)`
D. Starch and `H_(2)O_(2)`

Answer

To solve the question, we need to identify the indicator 'X' and the compound 'A' based on the information provided.

### Step-by-Step Solution:

1. **Understanding the Reaction Context**:
- The question states that we are studying the effect of iodide concentration on the reaction rate with hydrogen peroxide (H₂O₂) at room temperature.
- An indicator 'X' is used that forms a blue-colored complex with compound 'A'.

2. **Analyzing the Given Options**:
- The options provided are:
1. Methyl orange and iodine
2. Starch and iodine
3. Methyl orange and H₂O₂
4. Starch and H₂O₂

3. **Identifying the Blue Complex**:
- We need to determine which combination forms a blue-colored complex.
- Starch is known to form a blue complex with iodine. This is a well-known reaction where iodine interacts with the amylose component of starch, resulting in a blue color.

4. **Matching the Indicator and Compound**:
- Since iodine (the indicator) forms a blue complex with starch (the compound), we can conclude:
- Indicator 'X' = Iodine
- Compound 'A' = Starch

5. **Final Conclusion**:
- Therefore, the correct answer is that the indicator 'X' is iodine and the compound 'A' is starch.

### Answer:
The indicator 'X' and compound 'A' respectively are:
- Indicator 'X': Iodine
- Compound 'A': Starch