The reduction of an oxide by aluminium is called:

(1) Bayer's process

(2) Goldschmidt's aluminothermite process

(3) Hall's process

(4) van Arkel process

For which of the following metals Bessemerisation process is important?

I : Fe, II : Cu, III : Al, IV : Silver :

(1) I, II                                     

(2) II, III

(3) I, III                                     

(4) all

The chemical composition of "slag" formed during the smelting process in the extraction of copper is:

1. Cu₂ + FeS                                    

2. FeSiO₃

3. CuFeS                                         

4. Cu₂S + FeO

Which of the following statement is incorrect about the extractive metallurgy of copper?

(1) Matte chiefly consists of cuprous sulfide and some ferrous sulphide.

(2) Most of the impurity of iron sulphide is removed as fusible slag during roasting.

(3) The copper pyrites is concentrated by froth floatation process.

(4) self reduction and electrolysis respectively. 

Which of the following process is used in the extractive metallurgy of magnesium?

1. Fused salt electrolysis

2. Self reduction

3. Aqueous solution electrolysis

4. Thermite process.

White bauxite is purified by:

(1) Baeyer's process                               

(2) Hoop's process

(3) Serpeck's process                             

(4) Hall's process 

In the purification of impure nickel by Mond's process, metal is purified by:

(1) Electrolytic reduction

(2) Vapour phase thermal decomposition

(3) Thermite reduction

(4) Carbon reduction

What is the composition of the anode mud used in the electrolytic refining of silver?

1. Zn, Cu, Ag, Au

2. Zn, Ag, Au

3. Cu, Ag, Au

4. Au only

A substance that can act as collector in the froth floatation method is -

1. Sodium xenate.             

2. Sodium pyrophosphate.

3. Sodium nitroprusside.   

4. Sodium ethyl xanthate. 

AgCl on fusion with sodium carbonate, gives:

1. $A{g}_{2}C{O}_3$                       

2. $A{g}_{2}O$

3. $Ag$                               

4. $A{g}_2{C}_2$