Question

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

• A. $5\times {10}^{6}N/m^2$
• B. $6\times {10}^{3}N/m^2$
• C. 10 atmosphere
• D. $7.79\times {10}^{5}N/m^2$

Answer 1

Answer: (D)

$7.79\times {10}^{5}N/m^2$

Moles of $O_2=\frac{8}{32}=\frac{1}{4}$

Moles of $N_2=\frac{14}{28}=\frac{1}{2}$

Moles of $C{O}_2=\frac{22}{44}=\frac{1}{2}$

Thus total moles in the mixture=$\frac{1}{4}+\frac{1}{2}+\frac{1}{2}=\frac{5}{4}$

Using Ideal Gas Equation,

$PV=nRT$

$⟹P=\frac{nRT}{V}=\frac{\frac{5}{4}\times 8.3\times 300}{4\times {10}^{-3}}N/m^2\approx 7.79\times {10}^{5}N/m^2$