The volume V of an enclosure contains a mixture of three gases, 16 g of oxygen, 28 g of nitrogen and 44 g of carbon dioxide at absolute temperature T. Consider R as universal gas constant. The pressure of the mixture of gases is :

(A) $\frac {3RT}{V}$ (B) $\frac {5}{2} \frac {RT}{V}$

(C) $\frac {88RT}{V}$ (D) $\frac {4RT}{V}$

(C) $\frac {88RT}{V}$ (D) $\frac {4RT}{V}$

*Solution*

We have, $PV=nRT$

$\therefore PV = ({n_{{O_2}}} + {n_{{N_2}}} + {n_{C{O_2}}})RT$

$ \Rightarrow PV = \left( {\frac{{16}}{{32}} + \frac{{28}}{{28}} + \frac{{44}}{{44}}} \right)RT = 2.5RT$

$\therefore P = \frac{5}{2}\frac{{RT}}{V}$

Answer: (B)