Question

In a flask of volume $V$ litres, $0.2mol$ of oxygen, $0.4mol$ of nitrogen, $0.1mol$ of ammonia and $0.3mol$ of helium are enclosed at ${27}^{\circ }C$. If the total pressure exerted by these non-reacting gases is one atmosphere, the partial pressure exerted by nitrogen is :

• A. $0.1atmosphere$
• B. $0.2atmosphere$
• C. $0.3atmosphere$
• D. $0.4atmosphere$

Answer 1

Answer: (D)

$0.4atmosphere$

As we know,

Partial pressure = Mole fraction x total pressure

$\therefore P_{N_2}=X_{N_2}\times P_{total}$

$P_{N_2}=\frac{0.4}{0.2+0.4+0.1+0.3}\times 1=0.4atm$