Question

A and B are two identical vessel contains 15 grams at one atmospheric and 298 Kelvin The vessel B contains 75 gram of a gas X2 to at same temperature and pressure the vapour density of x 2 is ?

Answer 1

see PV = nRT = constant

so now the ratio of given mass and molecular mass will also be constant.

therefotre

15/30 = 75/molecular mass of gas

which gives the unknown molecular mass as 150

now we know that

vapour density = molecular mass/2

                          =150/2

                         =75

so the vapour density = 75