Carbon cannot be used to produce magnesium by chemical reduction of $MgO$ because

Predict conditions under which $Al$ might be expected to reduce $MgO$.

Identify the reaction that does not take place during the smelting process of copper extraction.

State the role of silica in the metallurgy of copper.

The main reactions occurring in a blast furnace during the extraction of iron from haematite are $....$.
$(i)$ $Fe_2O_3 + 3CO \to 2Fe + 3CO_2$
$(ii)$ $FeO + SiO_2 \to FeSiO_3$
$(iii)$ $Fe_2O_3 + 3C \to 2Fe + 3CO$
$(iv)$ $CaO + SiO_2 \to CaSiO_3$

The Ellingham diagram represents: