Write the name of the compound, when iron is corroded?

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. 8 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? 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. 11 i) Among iron and aluminium which rusts easily?
ii) What are the conditions, necessary for rusting of iron?