Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true? (RPMT 2007)

The standard free energies of formation (Gf°) of most of the sulphides are greater than those of CS2 and H2S. Hence, neither carbon nor hydrogen can reduce metal sulphides to metal. The standard free energies of formation of oxides are much lower than those of SO2. Therefore, oxidation of metal sulphides to metal oxides is thermodynamically favourable. Hence, sulphide ore is roasted to the oxide before reduction. 10. Identify the reaction that does not take place in a blast furnance. (AIPMT 2008) (a) 2Fe2O3 + 3C -> 4Fe + 3CO2 (b) CO2 + C -> 2CO (c) CaCO3 -> CaO + CO2 (d) FeO + SiO2 -> FeSiO3