Final answer:
The molecular mass of the hydrocarbon gas is calculated by dividing the mass of the gas by the number of moles. Given a mass of 6 g and a volume of 4.8 dm³, the molecular mass is found to be approximately 28 g/mol.
Step-by-step explanation:
The question involves calculating the molecular mass of a hydrocarbon gas given its mass and volume at standard temperature and pressure (STP). To find the molecular mass, we can use the molar volume of a gas at STP, which is 22.4 dm³/mol.
First step is to calculate the number of moles of the gas using the volume provided:
- Volume of the gas = 4.8 dm³
- Molar volume at STP = 22.4 dm³/mol
- Number of moles (n) = Volume of the gas / Molar volume at STP
- n = 4.8 dm³ / 22.4 dm³/mol
- n = 0.2142857 mol
Now that we have the number of moles, we can find the molecular mass (M) using the mass of the gas:
- Mass of the gas = 6 g
- Number of moles (n) = 0.2142857 mol
- Molecular mass (M) = Mass of the gas / Number of moles
- M = 6 g / 0.2142857 mol
- M ≈ 28 g/mol
Therefore, the molecular mass of the hydrocarbon gas is approximately 28 g/mol.