Exercise 1Question 1
Which of the ores mentioned in Table 6.1 can be concentrated by magnetic separation method?

Exercise 1 Question 2
What is the significance of leaching in the extraction of aluminium?

Exercise 1Question 3
The reaction,
      Cr₂O₃  +  2Al    →    Al₂O₃  + 2Cr            (ΔG_o = -421kJ)
is thermodynamically feasible as is apparent from the Gibbs energy value. Why does it not take place at room temperature?

Exercise 1 Question 4
Is it true that under certain conditions, Mg can reduce SiO₂ and Si can reduce MgO? What are those conditions?

Exercise 2 Question 2 

What is the role of depressant in froth floatation process?

Exercise 2 Question 3
Why is the extraction of copper from pyrites more difficult than that from its oxide ore through reduction?

Exercise 2 Question 4
Explain:   (i) Zone refining    (ii) Column chromatography.

Exercise 2 Question 6
Name the common elements present in the anode mud in electrolytic refining of copper. Why are they so present ?

Exercise 2 Question 10 

What is meant by the term "chromatography"?

Exercise 2Question 11
What criterion is followed for the selection of the stationary phase in chromatography?

Exercise 2 Question 12
How is leaching carried out in case of low grade copper ores?

Exercise 2 Question 13
Why is zinc not extracted from zinc oxide through reduction using CO?

Exercise 2Question 14
The value of Δ_fG^ø for formation of Cr₂O₃ is - 540 kJmol^-1 and that of Al₂ O₃ is - 827 kJmol^-1. Is the reduction of Cr₂O₃ possible with Al?

Exercise 2 Question 15
Out of C and CO, which is a better reducing agent for ZnO ?

Exercise 2 Question 16
The choice of a reducing agent in a particular case depends on thermodynamic factor. How far do you agree with this statement? Support your opinion with two examples.

Exercise 2 Question 17
Name the processes from which chlorine is obtained as a by-product. What will happen if an aqueous solution of NaCl is subjected to electrolysis?

Exercise 2 Question 18
What is the role of graphite rod in the electrometallurgy of aluminium?

Exercise 2 Question 19
Outline the principles of refining of metals by the following methods:
(i) Zone refining
(ii) Electrolytic refining
(iii) Vapour phase refining

Question 22 

How can you separate alumina from silica in bauxite ore associated with silica? Give equations, if any.

Exercise 2 Question 24
How is 'cast iron' different from 'pig iron"?

Exercise 2 Question 26 

Why copper matte is put in silica lined converter?

Question 27
What is the role of cryolite in the metallurgy of aluminium?