Question

Concentration-time graph for an equilibrium reaction is shown above. Kc for the reaction is

• A. 20
• B. 2
• C. 0.2
• D. 5

Answer 1

The correct option is A 20

From the graph,
formation of [B] = twice the disappearanc of A.
Hence the equilibrium reaction,
$A_{\left(g\right)}\rightleftharpoons 2B_{\left(g\right)}$
At equilbrium,
[A] = 5 M
[B] = 10
$K_c=\frac{[B{]}^2}{\left[A\right]}=\frac{{10}^2}{5}=20M$