In which of the following reactions,standard reaction entropy change`(DeltaS^(@))`is positive and standard Gibb,s energy change`(DeltaG^(@))`decreases sharply with increasing temperature?

Options

A. C graphite `+ (1)/(2) O_(2) (g) rarr CO(g)`
B. `CO(g) + (1)/(2) O_(2)(g) rarr CO_(2)(g)`
C. `Mg(s) + (1)/(2) O_(2) (g) rarr MgO(s)`
D. `(1)/(2)C` graphite `+ (1)/(2) O_(2)(g) rarr (1)/(2) CO_(2)(g)`

Answer

A

Explanation

In the first reaction `C(gr) + (1)/(2) O_(2)(g) rarr CO(g) Delta S^(@)=` +ve
Therefore `Delta G^(@)= Delta H^(@)- T Delta S` that means the value of `Delta G` decrease on increase temperature.