Metals are required for a variety of purposes. For this we need their extraction from their ores. Ores mined…
Metals are required for a variety of purposes. For this we need their extraction from their ores. Ores mined from the earth are usually contaminated with many impurities which must be removed prior to the extraction of metals. The extraction of pure metal involves the following steps :
(1) Concentration of ore
(2) Extraction of the metal from the concentrated ore
(3) Refining of the metal
(a) Name an ore of Mercury and state the form in which Mercury is present in it.
(b) What happens to zinc carbonate when it is heated strongly in a limited supply of air ?
(c) The reaction of a metal A with Fe2O3 is highly exothermic and is used to join railway tracks.
(I) Identify the metal A and name the reaction taking place.
(II) Write the chemical equation for the reaction of metal A with Fe2O3.
Solution
(a) Cinnabar ; HgS (Sulphide form)
(b) It forms Zinc oxide (Calcination)
Alternate answer: ZnCO3 (s) $\xrightarrow{\text{heat}}$ ZnO + CO2
(c) (I) Aluminium, Thermit Reaction
(II) Fe2O3 + 2Al → 2Fe + Al2O3 + Heat