Question

The equilibrium $A_4\left(g\right)+6B_2\left(g\right)\rightleftharpoons 4A{B}_3\left(g\right)$ is established in a closed container by taking equal moles of $A_4\left(g\right)$ and $B_2\left(g\right)$. Which of the following options must be correct at equilibrium?

• A. $\left[A_4\right]<[B{]}_2$
• B. $\left[B_2\right]>\left[A{B}_3\right]$
• C. $\left[A_4\right]<\left[A{B}_3\right]$
• D. None of the above

Answer 1

Answer: (D)

None of the above

At equilibrium, rate of forward reaction is equal to rate of backward reaction.

$R_{forward}=\frac{[A{B}_3{]}^4}{\left[A_4\right][B_2{]}^6}$

$R_{backward}=\frac{\left[A_4\right][B_2{]}^6}{[A{B}_3{]}^4}$

So the answer is none of the above.