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

A major impurity in pig iron is:

1. Carbon

2. Silicon

3. Phosphorus

4. Manganese

In the extraction of aluminium by the Hall-Heroult process, purified ${\mathrm{Al}}_2{\mathrm{O}}_3$ is mixed with ${\mathrm{CaF}}_2$ to:

Choose the correct option:
1. a and b
2. b and c
3. c and d
4. a and d

Aluminium is extracted from alumina Al₂O₃ by electrolysis of a molten mixture of:

1. ${\mathrm{Al}}_2{\mathrm{O}}_3+\mathrm{HF}+{\mathrm{NaAlF}}_4$

2. ${\mathrm{Al}}_2{\mathrm{O}}_3+{\mathrm{CaF}}_2+{\mathrm{NaAlF}}_4$

3. ${\mathrm{Al}}_2{\mathrm{O}}_3+{\mathrm{Na}}_3{\mathrm{AlF}}_6+{\mathrm{CaF}}_2$

4. ${\mathrm{Al}}_2{\mathrm{O}}_3+\mathrm{KF}+{\mathrm{Na}}_3{\mathrm{AlF}}_6$

Which of the following metals can be purified by electrolytic refining?

1. Cu, and Zn     

2. Ge, and Si     

3. Zr, and Ti     

4. Zn, and Hg

The correct match among the following is:

What happens in the extraction of chlorine by electrolysis of brine?

1. Oxidation of $C{l}^{-}$ ion to chlorine gas occurs.

2. Reduction of $C{l}^{-}$ ion to chlorine gas occurs.

3. For overall reaction $∆\mathrm{G}°$has negative value.

4. A displacement reaction takes place.

Consider the following metallurgical process:

Sulphide  \(\xrightarrow[]{\Delta }\)  oxide  \(\xrightarrow[]{\Delta }\)
Impure metal \(\xrightarrow[]{\Delta }\) pure metal

The processes A, B, and C in the above mentioned reaction are, respectively:

1. Calcination, smelting, and electrolysis

2. Roasting, smelting, and electrolysis

3. Calcination, auto reduction, and bessemerisation

4. Roasting, aluminothermic reduction, electrolysis

Consider the following reactions at 1000 ^oC.

(I) ZnS + 1/2O₂(g)  \(\xrightarrow[]{\Delta }\)  ZnO(g);  ∆G^o = -360 kJ mol^-1
(II) Cs + 1/2O₂(g)  \(\xrightarrow[]{\Delta }\) CO(g); ∆G^o = -460 kJ mol^-1  

Choose the correct statement about the above reactions at 1000 ^oC:

1. ZnO is more stable than CO

2. ZnO can be reduced to Zn by C

3. ZnO, and CO are formed at an equal rate

4. ZnO can not be reduced to Zn by C

2MS + 3O₂ → 2MO + 2SO₂
2MO + MS → 3M + SO₂

The metal M in above-mentioned reaction is:

1. Mg

2. Pb

3. Sn

4. Fe