Question

A vessel of volume 4 litres contains a mixture of 8gms of O${}_2$, 14 gms of N${}_2$ and 22 gms of CO${}_2$ at 27${}^0$C. The pressure exerted by the mixture is

• A. 10 atmosphere
• B. 5x10${}^6$ N/m${}^2$
• C. 7.79 x 10${}^5$ N/m${}^2$
• D. 6x10${}^5$5 N/m${}^2$

Answer 1

The correct option is C 7.79 x 10${}^5$ N/m${}^2$

8gms of oxygen=0.25 mole of oxygen molecules.

14gms of nitrogen=0.5 mole of nitrogen molecules.

22gms of carbon-di-oxide=0.5 mole of carbon-di-oxide molecules.

From Dalton's law of pressure,

Total pressure= sum of individual partial pressures,

Hence n=0.25+0.5+0.5=1.25 moles

$PV=nRTP=\frac{1.25\times 8.314\times 300}{4}P=7.79\times {10}^{5}N/m^2$