Carbon cannot be used in the reduction of `A1_(2)O_(3)` because:

Options

A. it is non-metal
B. the heat of formation of `CO_(2)` is more than that `A1_(2)O_(3)`
C. pure carbon is not easily available
D. the heat of formation of `A1_(2)O_(3)` is too high

Answer

D

Explanation

IN Ellingham diagram, the `Delta G^(@)` of `A1_(2)O_(3)` lies below that of `CO_(2)`. If reduction is carried out at very high temperature, the `A1` produced will react with carbon froming `A1_(4)C_(3)`.