Equilibrium Question 801
Question: One mole of $ O_2(g) $ and two moles of $ SO_2(g) $ were heated in a closed vessel of one-litre capacity at 1098 K. At equilibrium 1.6 moles of $ SO_3( g ) $ were found. The equilibrium constant $ K_{c} $ of the reaction would be
Options:
A) 30
B) 40
C) 80
D) 60
Show Answer
Answer:
Correct Answer: C
Solution:
$ \begin{aligned} & \begin{matrix} {} & {} & & O_2+2SO_2\rightarrow 2SO_3 \\ \end{matrix} \\ & \begin{matrix} at,t=0 & {} & 1 & {} \\ \end{matrix},\begin{matrix} 2 & {} & {} & 0 \\ \end{matrix} \\ & \begin{matrix} at,equil\text{.} & (1-\alpha ) & 2(1-\alpha ) & 2\alpha \\ \end{matrix} \\ \end{aligned} $ Given at equilibrium $ 2\alpha =1.6 $
$ \alpha =0.8 $
$ K_{C}=\frac{{{(2\alpha )}^{2}}}{(1-\alpha ){{(2-2\alpha )}^{2}}}=\frac{{{(0.8)}^{2}}}{(1-0.8){{(1-0.8)}^{2}}} $
$ =\frac{0.64}{0.008} $
$ K_{C}=80 $