A mixture of H2 and N2 has a density 6.0 times that of hydrogen gas under the same conditions (H2=2, N2=28 g/mol). The mass percent of H2 in the mixture is

JEE Advanced levelSingle correct optionDifficulty 3 of 3mc104

A mixture of $H X_{2}$ and $N X_{2}$ has a density $6.0$ times that of hydrogen gas under the same conditions ( $H X_{2} = 2$ , $N X_{2} = 28$ g/mol). The mass percent of $H X_{2}$ in the mixture is

Average molar mass = 6.0 x 2 = 12 g/mol. For mole fraction x of

H X_{2}

: 2x + 28(1-x) = 12, x = 0.6154. Mass % of

H X_{2}

= (2x/12) x 100 = 10.26%.