The density of a gas at STP is 1.5 g/L. Its molecular weight is

Options

A. 22.4
B. 33.6g
C. 33.6
D. 44.8

Answer

To find the molecular weight of a gas given its density at STP (Standard Temperature and Pressure), we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Given Information**:
- The density of the gas at STP is given as 1.5 g/L.

2. **Calculate the Mass of 1 Liter of Gas**:
- Since the density is 1.5 g/L, this means that 1 liter of the gas weighs 1.5 grams.

3. **Calculate the Mass of 22.4 Liters of Gas**:
- At STP, 1 mole of any ideal gas occupies 22.4 liters. Therefore, to find the mass of 1 mole of the gas, we multiply the mass of 1 liter by the volume of 1 mole:
\[ \text{Mass of 1 mole} = 1.5 \, \text{g/L} \times 22.4 \, \text{L} = 33.6 \, \text{g} \]

4. **Determine the Molecular Weight**:
- The molecular weight (or molar mass) of the gas is equal to the mass of 1 mole of the gas, which we calculated to be 33.6 grams.

5. **Final Answer**:
- Therefore, the molecular weight of the gas is **33.6**.

### Summary:
The molecular weight of the gas is **33.6**.

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