Question

Reduction of metal oxide to metal becomes easier if the metal obtained is in liquid state. Why?

Answer 1

Entropy of a metal in the liquid state is higher than that of the same metal in the solid state (S_liquid > S_solid). So, when the metal formed is in the liquid state and the metal oxide being reduced is in the solid state, the value of entropy change (ΔS) for the reduction reaction is more on the positive side. When the value of TΔS increases and that of ΔH remains the same, the value of ΔG_r^° for the reduction reaction becomes negative and thus reduction becomes easier.