Question

A gas cylinder filled with hydrogen holds 5 g of the gas.The same cylinder holds 85 g of gas X under same
temperature and pressure. Calculate :
(a) vapour density of gas X,
(b) molecular weight of gas X.​

Answer 1

Answer:

a. 17      

b. 34

Explanation:

Given that the container is same. Therefore, volume will also be the same.

This leads to STP condition.

therefore no of moles of both the gases will be equal.

In the first container filled with H2

no of moles= 5/2 [given mass/molar mass]

therefore no of moles of X gas will also be 5/2

5/2=85/MM

......MM=34......

vapour density of a gas= MM(of the gas)/MM(of reference gas)

Reference gas is usually taken as hydrogen when no other gas is mentioned.

therefore,

V Density of X=34/2

=17