Which method will you use to reduce the following ?
(i) Oxides of less reactive metals
(ii) Oxides of moderately reactive metals
(iii) Oxides of highly reactive metals.
explain by giving a suitable example.

Explanation

(i) `2HgO overset("Heat")rarr 2Hg + O_(2)`
`2Cu_(2)O + Cu_(2)S overset("Heat")rarr 6Cu + SO_(2)`
(ii) Reduction using carbon
`ZnO + C rarr Zn + CO`
Sometimes, some highly reactive metals are used as reducing agents.
e.g., `3MnO_(2) + 4Al rarr 3Mn + 2Al_(2)O_(3) + "heat"`
or `Fe_(2)O_(3) + 2Al rarr 2Fe + Al_(2)O_(3) + "heat"`
(ii) Electrolytic reduction
e.g., Na, Mg and Ca are obtained by electrolysis of their molten chlorides.