NaCN is a depressant that is used:
1. | To Separate PbS from ZnS by forming a complex with PbS. |
2. | To Separate PbS from ZnS by forming a complex with ZnS. |
3. | To Form froth. |
4. | As a collector. |
Ellingham's diagram for the formation of is a straight line in the given graph.
This is due to:
1. Increase in entropy during formation.
2. Decrease in entropy during formation.
3. Entropy remains constant during formation.
4. Can not be predicted.
Why is roasting important in the iron metallurgy process?
1. | FeO gets oxidized to Fe2O3 which does not combine with acidic SiO2 |
2. | SiO2 is an acidic oxide which can combine with metallic oxides i.e. FeO, and Fe2O3 |
3. | FeO when roasted get oxidized to more basic Fe2O3 |
4. | None of the above. |
The fundamental principle of froth flotation process is:
1. | Impurities and metal ore have different wetting properties. |
2. | Impurities and metal ore have different solubility. |
3. | Impurities and metal ore have different diversity. |
4. | Impurities and metal ore have different compressive powers. |
4M + 8CN- + 2H2O + O2 4[M(CN)2]- + 4OH-
2[M(CN)2]- + Zn[Zn(CN)4]2- + 2M
The metal M in above-mentioned reaction is:
1. Nickel
2. Silver
3. Copper
4. Mercury
The extraction of gold and silver involves leaching with CN- ion. Silver is later recovered by:
1. Liquation
2. Distillation
3. Zone refining
4. Displacement with Zn
The substance that acts as a collector in the froth flotation method is:
1. Sodium xenate.
2. Sodium pyrophosphate.
3. Sodium nitroprusside.
4. Sodium ethyl xanthate.
Which of the following is an incorrect match?
1. Kaolinite - Al2(OH)4Si2O5
2. Cuprite - Cu2O
3. Siderite - FeCO3
4. Calamine - ZnSO4
Among the following a non-oxide ore is:
1. Malachite
2. Cuprite
3. Zincite
4. Bauxite
2MS + 3O2 → 2MO + 2SO2
2MO + MS → 3M + SO2
The metal M in above-mentioned reaction is:
1. Mg
2. Pb
3. Sn
4. Fe