Question

An oxide of metal has 47% by mass of oxygen.Metal M has atomic mass of 24. What is the empirical formula of the oxide?

Answer 1

The formulae of the oxide is :

M x O y

Let X be moles of M and y be moles of Oxygen.

Mass of oxygen is 0.47g

Mass of M is 0.53g

Moles of M = 0.53 / 24 = 0.02

Moles of Oxygen = 0.47 / 16 = 0.03

Mole ratio :

M : O = 0.02 : 0.03

= 2:3

The empirical formula of the oxide is thus :

M₂O₃