Question

1) 1.12 dm3 of a gas at STP is found to weigh 3.55g.Find molecular weight and vapour density of gas
2)5.6 dm3 of a gas at STP weighs 11g Find out its relative molecular mass & vapour density

Answer 1

1.
n = mols of gas = 1.12/22.4 = ?
n = grams/molar mass. You have grams and n, solve for molar mass.

Then vapor density = molar mass/molar mass H2 = molar mass/2.016 = ?

2. See #1.