Question

10g of hydrogen and 46g of nitrogen are mixed in a container of volume one litre calculate mole fraction of hydrogen

Answer 1

Answer : The mole fraction of hydrogen will be, 0.76

Explanation :  Given,

Mass of $H_2$ = 10 g

Molar mass of $H_2$ = 2 g/mole

Mass of $N_2$ = 46 g

Molar mass of $N_2$ = 28 g/mole

First we have to calculate the moles of $H_2$ and $N_2$.

$\text{Moles of }H_2=\frac{\text{Mass of }H_2}{\text{Molar mass of }H_2}=\frac{10g}{2g/mole}=5moles$

and,

$\text{Moles of }N_2=\frac{\text{Mass of }N_2}{\text{Molar mass of }N_2}=\frac{46g}{28g/mole}=1.6moles$

Now we have to calculate the mole fraction of $H_2$ and $N_2$.

$\text{Mole fraction of }H_2=\frac{\text{Moles of }H_2}{\text{Moles of }H_2+\text{Moles of }N_2}$

$\text{Mole fraction of }H_2=\frac{5}{5+1.6}=0.76$

and,

$\text{Mole fraction of }N_2=\frac{\text{Moles of }N_2}{\text{Moles of }H_2+\text{Moles of }N_2}$

$\text{Mole fraction of }N_2=\frac{1.6}{5+1.6}=0.24$

Therefore, the mole fraction of hydrogen will be, 0.76