For the reaction `A+B hArr C+D`, the initial concentrations of A and B are equal. The equilibrium concentration of C is two times the equilibrium concentration of A. The value of equilibrium constant is ………..

Options

A. `1`
B. `2`
C. `3`
D. `4`

Answer

D

Explanation

`{:(,A,+,B,hArr,C,+,D),(t=0,a,,a,,0,,0),(t_("Eq"),a-x,,a-x,,x,,x):}`
Given that concentration of `D` is twice of `A`.
`:. x=2(a-x)` or `(a-x)=x/2`
`K=(x xx x)/((a-x)(a-x))=(x xx x)/(x/2xxx/2)=4`