(a) PbS+2PbO→3Pb+SO, (self reduction) (b) Silica is added to remove impurity of Fe in the form of slag FeSiO3. Hence, this statement is wrong. (c) Sulphide ore is partially oxidized first by roasting and then self reduction of Cu takes place to produce blister copper. Cu2S+
3
2
O2→Cu2O+SO2↑ Cu2S+2Cu2O→6Cu+SO2↑ (self reduction) The molten copper obtained is poured in to large container and allowed to coal and during cooling the dissolved SO2 comes upto the surface and forms blisters. It is known as blister copper. (d) 2Na[