If we look carefully at the Ellingham diagram (Fig.7), we find that at 983 K, the curves intersect. `Delta G^(@)` involving change of CO to `CO_(2)(CO,CO_(2))` is more as compared to the value involving change of C to `CO_(2)(C,CO_(2))`. This means that at this temperature or above it, coke (C ) is a better reducing agent. However, below this temperature, the reverse happens. Therefore, carbon monoxide (CO) is a better reducing agent at 673 K than coke (C ).
