Equilibrium Question 774
Question: At a certain temperature, only 50% HI is dissociated into $ H_2 $ and $ I_2 $ at equilibrium. The equilibrium constant is:
Options:
A) 1.0
B) 3.0
C) 0.5
D) 0.25
Show Answer
Answer:
Correct Answer: A
Solution:
$ \begin{aligned} & \begin{matrix} {} & {} & {} & HI\rightarrow \frac{1}{2}H_2+\frac{1}{2}I_2 \\ \end{matrix} \\ & \begin{matrix} at,t=0 & 0 & {} & \begin{matrix} {} & 0 & {} & {} \\ \end{matrix} \\ \end{matrix} \\ & \begin{matrix} at,eq. & (1-0.5) & (0.5) & (0.5) \\ \end{matrix} \\ \end{aligned} $
$ ( \therefore \alpha =\frac{50}{100}=0.5 ) $ Now $ K_{C}=\frac{{{(0.5)}^{1/2}}{{(0.5)}^{1/2}}}{0.5}=1 $
