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

Options

A. forward direction because `Q gt K_C`
B. reverse direction because `Q gt K_C`
C. forward direction because `Q lt K_C`
D. reverse direction because `Q lt K_C`

Answer

B

Explanation

`2A hArr B+ C, Delta G^(@) =2494.2` J
`rArr -0.434 = log K_C`
`rArr K_c = "antilog" (-0.434)`
`rArr K_c = 0.367`
Now, `[A] = (1)/(2) , [B] =2 and [C] = (1)/(2)`
Now, `Q_C = ([C] [B])/( [A]^(2) ) = (((1)/(2)) (2) )/( ((1)/(2))^(2) )= 4`
As `Q_c gt K_c`, hence reaction will shift in backward direction.