For the reaction, `A+B hArr C +D,` the initial concentration of A and B are equal, but the equilibrium concentration of Cis twice that of equilibrium concentration of A. The equilibrium constant is:

Options

A. 4
B. 9
C. `1//4`
D. `1//9`

Answer

A

Explanation

`{:(A ,+,B,hArr,C,+,D),(a ,,a,,0,,0),((a-x),,(a-x),,x,,x):}`
Given `x = 2(a-x)` or `x = (2a)/(3), K_(c) = (x^(2))/((a-x)^(2)) = ((2a//3)^(3))/((a-2a//3)^(2)) = 4`