Question

600 mg of gas X occupies 400 cm3 of volume. Calculate the molecular weight in grams.

Answer 1

Solution:

Suppose the gas is at STP conditions (Standard conditions for temperature and pressure).

At STP, one mole of any gas occupies a volume of 22400 cm³.

400 cm³ of a gas weighs 600 mg or 0.6 g

1 cm³ of a gas will weigh: (0.6 / 400) = 0.0015 g

22400 cm³ of a gas will weigh: 0.0015 × 22400 = 33.6 g

Answer: 33.6 g