Answer :

To determine the molecular weight of the gas given its density at Standard Temperature and Pressure (STP), we can use the following approach:

1. Understand the given information:
- Density of the gas at STP: [tex]\( 1.43 \, \text{g/L} \)[/tex]
- Molar volume of an ideal gas at STP: [tex]\( 22.414 \, \text{L} \)[/tex]

2. Use the formula for molecular weight:
The molecular weight (or molar mass) can be calculated using the following relationship:
[tex]\[ \text{Molecular Weight} = \text{Density} \times \text{Molar Volume} \][/tex]

3. Substitute the given values into the formula:
[tex]\[ \text{Molecular Weight} = 1.43 \, \text{g/L} \times 22.414 \, \text{L} \][/tex]

4. Perform the multiplication:
[tex]\[ \text{Molecular Weight} = 1.43 \times 22.414 = 32.05202 \, \text{g/mol} \][/tex]

5. Compare the calculated molecular weight with the given options:
The calculated molecular weight is [tex]\( 32.05202 \, \text{g/mol} \)[/tex]. Among the given options, the closest match to our calculated value is 32.

Therefore, the molecular weight of the gas, given its density at STP, is 32 g/mol.

The correct answer is:
(2) 32