Saved Bookmarks
| 1. |
Account for the following facts : (i) The reduction of a metal oxide is easier if the metal formed is in the liquid state at the temperature of reduction. (ii) Limestone is used in the manufacture of pig iron from haematite. (iii) Pine oil is used in the froth floatation process used to concentuate sulphide ores. |
|
Answer» (i) Entropy is higher when a metal is in the liquid state than when it is in the solid state. Thus TΔS increases, thus ΔG° becomes more negative and the reduction becomes easier. (ΔG = ΔH - TΔS) (ii) Limestone provides the flux (CaO) which combines with the impurities (SiO2) to form slag (CaSiO3). Thus it helps in the removal of impurities. (iii) Pine oil (Collector) enhances the non-wettability of the ore particles, which becomes lighter and hence rise to the surface along with the froth. |
|