Question

A 4.6 g sample of XO2 occupies 2.24 L at STP. Find X.

Answer 1

At STP, 1 mole of any gas occupies a volume of 22.4 L.

 4.6 g of a gas at STP occupies a volume of 2.24L.

Hence, the number of moles of gas $=\frac{2.24}{22.4} ​=0.1 moles.$

0.1 moles of a gas = 4.6 g.

1 mole of a gas $=4.6×\frac{1}{0.1}=46g$

Thus, the molecular weight of gas is 46g/mol.

It is the molecular weight of NO2 gas.

Hence = X is N (nitrogen)