Ncert Exercises & Solutions

5.7 What will be the pressure exerted by a mixture of 3.2 g of methane and 4.4 g of carbon dioxide contained in a 9 dm3 flask at 27 °C ?

It is known that,

p = \frac{m}{M} \times \frac{R T}{V}

For methane

(C H_{4}),

p_{C H_{4}} = \frac{3.2}{16} \times \frac{8.314 \times 300}{9 \times 10^{- 3}} [S i n c e 9 d m^{3} = 9 \times 10^{- 3} m^{3}]

[27 ° C = 300 K]

= 2.543 \times 10^{4} P a

P_{C O_{2}} = \frac{4.4}{44} \times \frac{8.314 \times 300}{9 \times 10^{- 3}}

= 2.771 \times 10^{4} P a

Total pressure exerted by the mixture can be obtained as:

p = p_{C H_{4}} + p_{C O_{2}}

= (5.543 \times 2.771 \times 10^{4}) P a

= 8.314 \times 10^{P a}

Hence, the total pressure exerted by the mixture is 8.314 ×

10^{4}

Pa.