At NTP, the mass of 1 litre of gas is 3 g. Molecular mass of the gas is _____________

Answer

To find the molecular mass of the gas, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Information**:
- We are given that at Normal Temperature and Pressure (NTP), the mass of 1 liter of the gas is 3 grams.

2. **Use the Ideal Gas Law Concept**:
- At NTP, 1 mole of an ideal gas occupies 22.4 liters.

3. **Calculate the Mass of 1 Mole of Gas**:
- Since we know the mass of 1 liter of gas is 3 grams, we can find the mass of 22.4 liters (which is 1 mole) by multiplying the mass of 1 liter by the volume of 1 mole.
- Mass of 1 mole of gas = Mass of 1 liter × Volume of 1 mole
- Mass of 1 mole of gas = 3 g/liter × 22.4 liters

4. **Perform the Calculation**:
- Mass of 1 mole of gas = 3 g × 22.4 = 67.2 grams

5. **Conclusion**:
- Therefore, the molecular mass of the gas is **67.2 grams**.

### Final Answer:
The molecular mass of the gas is **67.2 g**.

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