The mass of 5.6 dm³ of a certain gas at STP is 12.0 g. Calculate the relative molecular mass of the gas.

The vapour density of a gas is 8. What would be the volume occupied by 24.0 g of the gas at STP ?

State Avogadro's Law.

A cylinder contains 68 g of ammonia gas at s.t.p.

(i) What is the volume occupied by this gas?

(ii) How many moles and how many molecules of ammonia are present in the cylinder?

[N = 14, H = 1]

From A, B, C, D, which weighs the least —

A : 2 g. atoms of Nitrogen

B : 1 mole of Silver

C : 22.4 lits. of oxygen gas at 1 atmos. press. and 273 K

D : 6.02 x 10²³ atoms of carbon.

[Ag = 108, N = 14, O = 16, C = 12]