(i) State the volume occupied by 40 gm. of methane at stp if it's vapour density is 8.

(ii) Calculate the number of moles present in 160 g of NaOH.

[Na = 23, H = 1, O = 16]

Samples of O₂, N₂, CO and CO₂ under the same conditions of temperature and pressure contain the same number of molecules represented by X. The molecules of oxygen occupy V litres and have a mass of 8 g. Under the same conditions of temperature and pressure, what is the volume occupied by :

(i) X molecules of N₂.

(ii) 3X molecules of CO.

(iii) What is the mass of CO₂ in grams.

(iv) In answering the above questions, whose law has been used.

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

The gas law which relates the volume of a gas to the number of molecules of the gas is :

1. Avogadro's Law
2. Gay-Lussac's Law
3. Boyle's Law
4. Charles' Law

Correct the following — Equal masses of all gases under identical conditions contain the same number of molecules.