i) What is the composition of molten slag, formed in the extraction of iron in the blast furnace?
ii) What is the use of slag?

6 Why is that iron does not occur as a metal in the crust of the earth? What are the common compound forms in which iron occurs? Which of these is more often used for extracting iron? Why are carbon and limestone mixed with iron ore before feeding it into the blast furnace? Write the chemical equations for the reduction step and the slag formation step. 7 By what chemical processes do you obtain the following metals?
i) Mercury from HgO  ii) Iron from Fe₂O₃  iii) Manganese from MnO₂  iv) Sodium form NaCl  v) Aluminium from Al₂O₃. 9 Write the name of the compound, when iron is corroded? 10 Give reasons for the following
i. Na, K and Ca metals form hydrides by combination with hydrogen gas, but most other metals do not.
ii. Aluminium easily combines with oxygen but still it can be used for making kitchen utensils.