Question

The chloride of a metal contains $71$% chlorine by weight and the vapour density of it is $50$. The atomic weight of the metal will be :

• A. 29
• B. 58
• C. 35.5
• D. 71

Answer 1

The correct option is A 29

Molecular weigth $=2\times$ vapour density $=2\times 50=100g/mol$
100 g of compound contain 71 g of Cl and 29 g of metal.
71 g of Cl corresponds to 2 moles.
29 g of metal corresponds to 1 mole. Hence, the molecular weight of the metal is 29 g/mol.