(a) Name the metal which is extracted from the ore called 'rock salt'. (b) Name two ores of zinc. Write the names of the chemical compounds present in them and give their chemical formulae. (c) Explain how, mercury is extracted from its sulphide are (cinnabar). Give equations of the reactions involved. (d) In the electrolytic refining of a metal M, what would you take as anode, cathode and electrolyte? Name any five metals which are purified by electrolytic refining method.