Question

1.0 litre of $N_2$ and $\frac{7}{8}$ litre of $O_2$ at the same temperature and pressure were mixed together. What is the relation between the masses of the two gases in the mixture?

• A. $m_{N_2}=3m_{O_2}$
• B. $m_{N_2}=8m_{O_2}$
• C. $m_{N_2}=m_{O_2}$
• D. $m_{N_2}=16m_{O_2}$

Answer 1

The correct option is C $m_{N_2}=m_{O_2}$

22.4 L of $N_2$ at S.T.P. $=$ 28 g of $N_2$
1 L of $N_2$ at S.T.P $=1.25$ g of $N_2$
Also,
22.4 L of $O_2$ at S.T.P $=$ 32 g of $O_2$
$\frac{7}{8}$ L of $O_2$ at S.T.P. $=$ 1.25 g of $O_2$
$\therefore m_{N_2}=m_{O_2}$