A gas mixture contains H2 (2 g/mol) and He (4 g/mol) in equal masses. The mole fraction of H2 is

JEE Main levelSingle correct optionDifficulty 2 of 3mc097

A gas mixture contains $H X_{2}$ ( $2 g/mol$ ) and $He$ ( $4 g/mol$ ) in equal masses. The mole fraction of $H X_{2}$ is

Take 50 g of each:

H X_{2}

= 25 mol,

He

= 12.5 mol. Mole fraction of

H X_{2}

= 25/37.5 = 0.667.