`DeltaG^(Ө)` vs T plot in Ellingham diagram slopes downward for the reaction .

Options

A. `Mg + (1)/(2) O_(2) rarr MgO`
B. `2Ag + (1)/(2) O_(2) rarr Ag_(2) O`
C. `C + (1)/(2) O_(2) rarr CO`
D. `CO + (1)/(2) O_(2) rarr CO_(2)`

Answer

C

Explanation

`C(s) + (1)/(2) O_(2(g)) rarr CO_((g)) , Delta S` increase. Hence, as the temperature increases, `T Delta S` increases and hence `Delta G(Delta H - T Delta S)` decreases. In other words. The slope of the curve for formation of `CO` decreases. Howeve, for all other oxides, it increases.