By what chemical processes do you obtain the following metals?
i) Mercury from HgO  ii) Iron from Fe₂O₃  iii) Manganese from MnO₂  iv) Sodium form NaCl  v) Aluminium from Al₂O₃.

i) Mercury from mercuric oxide can be obtained by simple heating.
2HgO 2Hg + O₂ ii) Iron from iron oxide (Fe₂O₃) can be obtained by carbon reduction method i.e heating with coke.
2C + O₂   2CO
Fe₂O₃ + 3CO   2Fe + 3CO₂ iii) Manganese from manganese dioxide is obtained by alumino thermite process, i.e. heating with aluminium.
3MnO₂ + 4Al   2Al₂O₃ + 3Mniv) Sodium from sodium chloride is obtained by electrolytic reduction (electrolysis) of fused NaCl.
NaCl   Na⁺ + Cl^-
At anode  2Cl^-   Cl₂ + 2e^-
At cathode 2[Na⁼ +e^-   Na]
v) Al₂O₃   2 Al³⁺ + 3(O)^2-
At cathode 4[2Al³⁺ + 6e   2Al]
At anode 6O^2-   3O₂ + 12e^-.