An inorganic salt when heated evolves coloured gas which bleaches moist limus paper .The evolves gas is

Options

A. `NO_(2)`
B. `SO_(2)`
C. `N_(2)O`
D. `I_(2)`

Explanation

To determine the evolved gas from the heating of an inorganic salt that bleaches moist litmus paper, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Characteristics of the Gas**:
- The gas evolved is colored and has the ability to bleach moist litmus paper. This indicates that the gas is likely an oxidizing agent.

2. **Consider Possible Gases**:
- The options provided are NO2, SO2, N2O, and I2. We need to analyze each of these gases to see which one fits the description.

3. **Analyze Each Option**:
- **NO2 (Nitrogen Dioxide)**:
- NO2 is a brown gas that is known to bleach moist litmus paper due to its strong oxidizing properties.
- **SO2 (Sulfur Dioxide)**:
- SO2 is a colorless gas that does not bleach moist litmus paper; instead, it can turn it red due to its acidic nature.
- **N2O (Nitrous Oxide)**:
- N2O is a colorless gas and does not have bleaching properties.
- **I2 (Iodine)**:
- I2 is a purple solid that sublimates to a violet gas, but it does not bleach litmus paper.

4. **Conclusion**:
- Based on the analysis, the only gas that is colored and can bleach moist litmus paper is NO2. Therefore, the evolved gas from the inorganic salt when heated is NO2.

### Final Answer:
The evolved gas is **NO2**.

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