Solve this:

Solve this: In the metallurgy Of iron. during smelting process, CO is redtKing agent at the upper parl ot because (1) It is less concentrated in upper atmosphere (2) The CO formed Can be easily removed (3) In the lower atmosphere, there is no oxide to be reduced (4) The entropy change during CO/C02 is negative

The solution is as follows:

1. The correct option is (4).

2. This can be understood by the diagram below:

The CO and heat moves to upper part of the furnace. In upper part, the temperature is lower and the iron oxides (Fe2O3 and Fe3O4) coming from the top are reduced in steps to FeO. Thus, the reduction reactions taking place in the lower temperature range and in the higher temperature range, depend on the points of corresponding intersections in the ΔrG0 vs T plots.