Equilibrium Question 259
Question: One mole of a compound AB reacts with one mole of a compound CD according to the equation AB + CD ⇌ AD + CB. When equilibrium had been established it was found that $ \frac{3}{4} $ mole each of reactant AB and CD had been converted to AD and CB. There is no change in volume. The equilibrium constant for the reaction is [Kerala (Med.) 2003]
Options:
A) $ \frac{9}{16} $
B) $ \frac{1}{9} $
C) $ \frac{16}{9} $
D) 9
Show Answer
Answer:
Correct Answer: D
Solution:
$ AB $ + $ CD $ ⇌ $ AD $ + $ CD $ mole at $ t=0 $1 1 0 0
Mole at equilibrium $ ( 1-\frac{3}{4} ) $ $ ( 1-\frac{3}{4} ) $ ⇌ $ ( \frac{3}{4} ) $ $ ( \frac{3}{4} )$ 0.25 0.25 ⇌ 0.75 0.75
$ K_{c}=\frac{0.75\times 0.75}{0.25\times 0.25}=\frac{0.5625}{0.0625}=9 $
