Chemistry 12 Chapter 6 General Principles and Processes of Isolation of Elements Part 2

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II. Multiple Choice Questions (Type-II)

Note: In the following questions two or more options may be correct.

Question 14:

At the temperature corresponding to which of the points in Fig.6.1, will be reduced to by coupling the reaction with all of the following reactions?

(a)

(b) and

(c)

(i) Point A

(ii) Point B

(iii) Point D

(iv) Point E

Answer: (ii), (iv)

Question 15:

Which of the following options are correct?

(i) Cast iron is obtained by remelting pig iron with scrap iron and coke using hot air blast.

(ii) In extraction of silver, silver is extracted as cationic complex.

(iii) Nickel is purified by zone refining.

(iv) and Ti are purified by van Arkel method.

Answer: (i), (iv)

Question 16:

In the extraction of aluminium by Hall-Heroult process, purified is mixed with to

(i) Lower the melting point of .

(ii) Increase the conductivity of molten mixture.

(iii) Reduce into .

(iv) Acts as catalyst.

Answer: (i), (ii)

Question 17:

Which of the following statements is correct about the role of substances added in the froth floation process?

(i) Collectors enhance the non-wettability of the mineral particles.

(ii) Collectors enhance the wettability of gangue particles.

(iii) By using depressants in the process two sulphide ores can be separated.

(iv) Froth stabilisers decrease wettability of gangue.

Answer: (i), (iii)

Question 18:

In the Froth Floatation process, zinc sulphide and lead sulphide can be separated by ______________.

(i) Using collectors.

(ii) Adjusting the proportion of oil to water.

(iii) Using depressant.

(iv) Using froth stabilisers.

Answer: (ii), (iii)

Question 19:

Common impurities present in bauxite are ____________.

(i)

(ii)

(iii)

(iv)

Answer: (iii), (iv)

Question 20:

Which of the following ores are concentrated by froth floation?

(i) Haematite

(ii) Galena

(iii) Copper pyrites

(iv) Magnetite

Answer: (ii), (iii)

Question 21:

Which of the following reactions occur during calcination?

(i)

(ii)

(iii)

(iv)

Answer: (i), (iii)

Question 22:

For the metallurgical process of which of the ores calcined ore can be reduced by carbon?

(i) Haematite

(ii) Calamine

(iii) Iron pyrites

(iv) Sphalerite

Answer: (i), (ii)

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