Question

At ntp 5.6 litre of gas weight 8g. Its vapour density is

Answer 1

At NTP the volume of gas = 22.4 L 

Given volume of gas = 5.6 L

Therefore no of mole = $\frac{5.6}{22.4}$

no of mole = 1/4 = 0.25 moles 

vapor density = 2 * molecular weight 
molecular weight = = 0.25 * 8 = 2 

vapour density = 2*2=4 

Answer 2

1 mol of any gas at STP acquires 22.4 L

Moles of gas in 5.6 L is = 5.6 / 22.4 = 0.25

Molecular weight = w / n = 8 g / 0.25 mol = 32 g/mol

Vapour density = Molecular weight / 2
= 32 / 2
= 16

Vapour density of gas is 16