Equilibrium Question 257
Question: 0.1 mole of $ N_2{O_{4(g)}} $ was sealed in a tube under one atmospheric conditions at 25°C. Calculate the number of moles of $ N{O_{2(g)}} $ present, if the equilibrium $ N_2{O_{4(g)}} $ ⇌ $ 2N{O_{2(g)}} $
$ (K_{p}=0.14) $ is reached after some time [UPSEAT 2001]
Options:
A) $ 1.8\ \times \ 10^{2} $
B) $ 2.8\ \times \ 10^{2} $
C) 0.034
D) $ 2.8\ \times \ {10^{-2}} $
Show Answer
Answer:
Correct Answer: C
Solution:
$ \underset{0.1}{\mathop{N_2O_4}}, $ ⇌ $ \underset{0}{\mathop{2NO_2}}, $ (.1-a) 2a ∵ P µ 0.1 If V and T are constant (Pµ0.1+ a) $ P=\text{(0}\text{.1}+\alpha )/0.1 $
$ K_{p}=\frac{{{[2\alpha ]}^{2}}}{[0.1-\alpha ]}\times [ \frac{P}{0.1+\alpha } ] $ or $ K_{p}=\frac{40{{\alpha }^{2}}}{[0.1-\alpha ]}=0.14 $
$ \alpha =0.017 $
$ NO_2=0.017\times 2=0.034 $ mole
