Question

A gas cylinder holds 85 g of a gas ‘X’. The same cylinder when filled with hydrogen holds 8.5 g of hydrogen under the same conditions of temperature and pressure Calculate the molecular weight of ‘X’.

Answer 1

V.D. of 'X' = weight of certain volume of gas/weight of equal vol. of H₂

Under similar conditions of temp. and pressure

∴ V.D. of gas 'X' = wt of 1 gas cylinder of gas 'X'/ wt. of 1 gas cylinder of H₂ = 85 g/8.5g

V.D. of 'X' =10

∴ Molecular weight of gas 'X' = 2 x 10 = 20 g