Question

$1mole$ of $N_2{O}_4\left(g\right)$ at $300K$ is kept in a closed container under one atmosphere. It is heated to $600K$ when $20\%$ by mass of $N_2{O}_4\left(g\right)$ decomposes to $N{O}_2\left(g\right)$. The resultant pressure is :

• A. $1.2atm$
• B. $2.4atm$
• C. $2.0atm$
• D. $1.0atm$

Answer 1

The correct option is B $2.4atm$

$N_2{O}_4\rightleftharpoons 2N{O}_2$

No. moles of $N_2{O}_4$ $2N{O}_2$

At 300K $\frac{100}{92}=1.08$ 0

At 600K $\frac{80}{92}=0.86$ $\frac{20}{46}=0.43$
$\frac{P_1{V}_1}{P_0{V}_0}=\frac{n_{1}R{T}_1}{n_{0}R{T}_0}$
$\therefore P_1=\frac{(0.86+0.43)\times 600}{1.08\times 300}=2.38atm$

Hence, the correct option is B.