Question

Two moles of each reactant $A$ and $B$ are taken in a reaction flask. They react in the following manner,
$A(g)+B(g)\rightleftharpoons C(g)+D(g)$
At equilibrium, it was found that the concentration of $C$ is triple to that of $B$. The equilibrium constant for the reaction is

• A. $4.5$
• B. $6$
• C. $9$
• D. $\frac{1}{6}$

Answer 1

Answer: (C)

$K_p=\frac{p_C\cdot p_D}{p_A\cdot p_B}$
$=\frac{{\left(\frac{3x}{V}\right)}^2}{{\left(\frac{2-3x}{V}\right)}^2}$
$=\frac{9\times {\left(\frac{1}{2}\right)}^2}{4-12\times \frac{1}{2}+9\times {\left(\frac{1}{2}\right)}^2}$
$=9$