Question

Which of the following factors is of no significance for roasting sulphide ores to the oxidexs and not subjecting the sulphide ores to carbon reduction directly?

Solution

Correct option is

Metal sulphides are less stable then the corresponding oxides

 

The value of ∆G for the formation of CO2 is negative, ie, it is thermodynamically more stable than CS2. Also metal sulphides are thermodynamically more stable than CS2. Metal sulphides are more stable than the corresponding oxides, so they are roasted to convert into less stable oxides.

SIMILAR QUESTIONS

Q1

By which of the following processes, the ore is made porous?

Q2

Stainless steel has iron and

Q3

Thermite process is used in reduction of

Q4

Bauxite ore is made up of Al2O3 + SiO2 + TiO2 + Fe2O3. This ore is treated with conc. NaOH solution at 500 K and 35 bar pressure for few hours and filtered when hot. In the filtrate, the species present are

Q5

 

When copper pyrites is roasted in excess of air, a mixture of CuO + FeO is formed. FeO is present as impurities. This can be removed as slag during reduction of CuO. The flux added to form slag is

Q6

Willemite is

Q7

The temperature of the slag zone in the metallurgy of iron using blast furnace is

Q8

The ore that is concentrated by froth floatation process is

Q9

Native silver metal forms a water soluble complex with a dilute aqueous solution of NaCN in the presence of

Q10

Calamine is