Question

Mass of 0.5 cubic dm of hydrogen at pressure of 1 ar of Hg and at a temperature of 300 K was found to be 0.04 g . Calculate molar mass of hydrogen

Answer 1

First we have to calculate moles of hydrogen.

According to the ideal gas equation,
PV = nRT
n = PV/RT

Here , P = 1 bar
V = 0.5 cubic dm
R = 0.083 bar cubic dm / K mol
T = 300 K

Plugging the given values ,
n = 1 x 0.5/0.083 x 300 = 0.02 mol

Now it is given that Mass of hydrogen = 0.04 g
Number of moles of hydrogen = 0.02 mole

Molar mass of hydrogen =
Mass of hydrogen ÷ Moles of hydrogen
= 0.04 ÷ 0.02 = 2 g

Hence your required answer is 2 g

Hope This Helps You!

Answer 2

Solution is downside