Solution:
(1) Pig iron contains about 4% carbon and many impurities in smaller amount (e.g., S, P, Si, Mn). It can be moulded into variety of shapes
(2) Wrought iron is the purest form of carbon
(3) Blister copper has blistered appearance due to evolution of SO2
(4) Vapour phase refining is carried out for nickel by Mond's process