The standard Gibbs energy change at 300K for the reaction `2A hArr B+C` is 2494.2 J. at a given time, composition of the reaction mixture is `[A]=(1)/(2),[B]=2 and [C]=(1)/(2)`. The reaction proceeds in the `[R=8.314J//K//mol,c=2.718]`-

Options

A. forward direction because `Q lt K_(c)`
B. reverse direction because `Q lt K_(c)`
C. forward direction because `Q gt K_(c)`
D. reverse direction because `Q gt K_(c)`.

Answer

D

Explanation

`2AhArrB+C`
Given: `T=300K,DeltaG^(0)=2494.2J`,
`R=8.314J*K^(-1)*mol^(-1)`
Now, `DeltaG^(0)=-2.303RTlogK_(c)`
or, `2494.2=-2.303xx8.314xx300xxlogK_(c)`
or, `logK_(c)=-0.4342" "therefore K_(c)=0.3679`
`Q_(c)=([B][C])/([A]^(2))=(2xx(1)/(2))/((1//2)^(2))=4`
As `Q_(c) gt K_(c)`, the reactionn will proceed in the backward direction.