At `300K: DeltaG^(Theta) = DeltaH^(Theta) - T DeltaS^(Theta)`
`=- 41.16 - 300 xx (-4.24xx10^(-2))`
`=- 28.44 kJ`
Since, `DeltaG^(Theta)` is negative, hence recaiton is spontaneous is forward direction.
`DeltaG^(Theta) =- 2.3030 RT log K_(p)`
`-28.44 = - 2.303 xx 8.314 xx 10^(-3) xx 300 log_(10) K_(p)`
`K_(p) = 8.93 xx 10^(4)`
At `1200K: DeltaG^(Theta) = DeltaH^(Theta) - T DeltaS^(Theta)`
`=- 32.93 - 1200 (-2.96 xx 10^(-2))`
` =+ 2.59 kJ`
Positive value of `DeltaG^(Theta)` shows that the reaction is sponteneous in backward direction
`Deltag^(Theta) =- 2.303 RT log_(10) K_(p)`
`2.59 =- 2.303 xx 8.314 xx 1200 log K_(p)`
`K_(p) = 0.77`