Question

The mole percent of H2 and N2 in a mixture is 50% each, what is the mass percentage of H2?

(a) 12.5

(b) 25

(c) 50

(d) 87.5

Answer 1

The correct choice is (a) 12.5

To explain I would say: Let the moles be 50 each, => Mass of H2 = 100, Mass of N2 = 700, => Mass percentage of H2 = 100/(100 + 700)*100 = 12.5%.