Free NCERT Solutions For Class 12 Chemistry Chapter 6 : General Principles and Processes of Isolotion of Elements Free PDF Download

Intext exercise

Question 1:
Which of the ores mentioned can be concentrated by magnetic separation method?

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

NCERT EXERCISE

Question 1:
Copper can be extracted by hydrometallurgy but not zinc. Explain

Question 2:
What is the role of depressant in froth-floatation process?

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

Question 5:
Out of C and CO which is a better reducing agent at 673K?

Solution 5:

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

Question 7:
Write down the reactions taking place in different zones in the blast furnace during the extraction
of iron

Solution 7:

In the blast furnace reduction of iron oxides take place at different temperature ranges as shown
below.

Question 8:
Write chemical reactions taking place in the extraction of zinc from zinc blende.

Question 9:
State the role of silica in the metallurgy of copper.

Question 10:
What is meant by the term “chromatography”?

Question 12:
Describe a method for refining nickel.

Question 13:
How can you separate alumina from silica in a bauxite ore associated with silica? Give equations, if any.

Question 14:
Giving examples, differentiate between ‘roasting’ and ‘calcination’.

Question 15:
How is ‘cast iron’ different from ‘pig iron’?

Question 16:
Differentiate between minerals’ and ores’

Question 17:
Why copper matte is put in silica lined converter?

Question 20:
Why is zinc not extracted from zinc oxide through reduction using CO?

Question 23:
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.

Question 24:
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?

Question 25:
What is the role of graphite rod in the electrometallurgy of aluminium?

Question 26:
Outline the principles of refining of metals by the following methods:
(i) Zone refining
(ii) Electrolytic refining
(iii) Vapour phase refining

Question 27:
Predict conditions under which Al might be expected to reduce MgO