According to Ellingham diagram, the oxidation reaction of carbon to carbon monoxide may be used to reduce which one of the following oxides at the lowest temperature ?

Options

A. `Al_(2)O_(3)`
B. `Cu_(2)O`
C. `MgO`
D. `ZnO`

Answer

B

Explanation

In the graph of `Delta_(r ) G^(@)` vs T for formation of oxides, the `Cu_(2)O` line is almost at the top. So, it is quite easy to reduce oxide ores of copper directly to the metal by heating with coke both the lines of C, CO and `C, CO_(2)` are at much lower temperature (500-600)K.
`Cu_(2)O+C to 2Cu+CO`