Giving a suitable example, describe the importance of the formation of complex compounds in
(i) the estimation of hardness of water
(ii) the extraction of a particular metal from its natural source.

Giving one example in each of the following cases, discuss briefly the role of coordination compounds in (i) extraction metallurgy of metals (ii) analytical chemistry

Describe the role of (i) NaCN in the extraction of gold from its ore. (ii) Cryolite in the extraction of aluminium from pure alumina (iii) CO in the purification of Nickel.

(a) Which metal is extracted from bauxite ore? (b) Give the name of one ore of iron. Which iron compound is preent in this ore? Write its chemical formula. (c). Describe the extraction of zinc metal from its sulphide ore (zinc blende). Write equations of the reactions involved. (d) Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken. (e) name a common metal which is highly resistant to corrosion.

Discuss briefly giving an example in each case the role of coordination compounds in: (i) biological systems (iii) analytical chemistry (ii) medicinal chemistry and (iv) extraction/metallurgy of metals

A trivalent metal M occurs in nature in the form of its oxide, M_(2)O_(3) . The metal is widely used in making household utensils and bodiies of aircrafts. The metal is widely used in making household utensils and bodies of aricrafts. (i) Name the metal. (ii) Name the chief ore of the metal. (iii) Give the principles inviolved in the extraction of the metal from its ore.

(a) Name two metals which are found in free state in nature. (b) What chemical process is used for extracting a metal from its oxide ore? Name one metal which is extracted by this method. (c) Describe the extraction of zinc metal from its sulphide ore as well as its carbonate ore. Write equations of all the reactions involved.