The standard Gibbs energy changes (per mole of O2, in kJ) are 2M + O2 -> 2MO: -610 + 0.19 T, and 2C + O2 -> 2CO: -225 - 0.17 T. Carbon begins to reduce MO above a temperature closest to

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The standard Gibbs energy changes (per mole of $O X_{2}$ , in $kJ$ ) are $2 M + O X_{2} 2 MO$ : $- 610 + 0.19 T$ , and $2 C + O X_{2} 2 CO$ : $- 225 - 0.17 T$ . Carbon begins to reduce $MO$ above a temperature closest to

Carbon reduces

MO

when the oxide's line lies above the

CO

line, i.e. when the coupled

Δ G^{\circ}

is negative. At the crossover

- 610 + 0.19 T = - 225 - 0.17 T

, so

0.36 T = 385

and

T = 1069.4 K

. Above it, the carbon-to-

CO

line is lower and reduction proceeds.