Solutions of chapter 6. General Principle and Processes of Isolation of Elements

1

In the extraction of chlorine by electrolysis of brine ____________.

2

When copper ore is mixed with silica, in a reverberatory furnace copper matte is produced. The copper matte contains ____________.

3

Which of the following reactions is an example of auto-reduction?

4

A number of elements are available in earth’s crust but most abundant elements are ____________.

5

Zone refining is based on the principle that ___________.

6

In the extraction of copper from its sulphideore, the metal is formed by the reduction of Cu₂O with

7

Brine is electrolysed by using inert electrodes. The reaction at anode is ________.

8

In the metallurgy of aluminium ________________.

9

Electrolytic refining is used to purify which of the following metals?

10

Extraction of gold and silver involves leaching the metal with CN^– ion. The metal is recovered by ________________.

11

Choose the correc

12

Below point ‘A’ FeO can ______________.

13

For the reduction of FeO at the temperature corresponding to point D, which of the following statements is correct?

14

At the temperature corresponding to which of the points in Fig, FeO will be reduced to Fe by coupling the reaction 2FeO → 2Fe + O₂ with all of the following reactions?

(a) C + O₂→ CO₂

(b) 2C + O₂→ 2CO and

(c) 2CO + O₂→2 CO₂

15

Which of the following options are correct?

16

In the extraction of aluminium by Hall-Heroult process, purified Al₂O₃ is mixed with CaF₂ to

17

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

18

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

19

Common impurities present in bauxite are ____________.

20

Which of the following ores are concentrated by froth floation?

21

Which of the following reactions occur during calcination?

22

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

23

The main reactions occurring in blast furnace during extraction of iron from

haematite are ________.

24

In which of the following method of purification, metal is converted to its volatile compound which is decomposed to give pure metal?

25

Which of the following statements are correct?

26

In the extraction of chlorine from brine _____________.

28

At temperatures above 1073K coke can be used to reduce FeO to Fe. How can you justify this reduction with Ellingham diagram?

29

Wrought iron is the purest form of iron. Write a reaction used for the preparation of wrought iron from cast iron. How can the impurities of sulphur, silicon and phosphorus be removed from cast iron?

30

How is copper extracted from low grade copper ores?

33

How do we separate two sulphide ores by Froth Floatation Method? Explain with an example.

34

The purest form of iron is prepared by oxidising impurities from cast iron in a reverberatory furnace. Which iron ore is used to line the furnace? Explain by giving reaction.

35

The mixture of compounds A and B is passed through a column of Al₂O₃ by using alcohol as eluant. Compound A is eluted in preference to compound B. Which of the compounds A or B, is more readily adsorbed on the column?

36

Why is sulphide ore of copper heated in a furnace after mixing with silica?

37

Why aresulphide ores converted to oxide before reduction?

38

Which method is used for refining Zr and Ti? Explain with equation.

39

What should be the considerations during the extraction of metals by electrochemical method?

40

What is the role of flux in metallurgical processes?

41

How are metals used as semiconductors refined? What is the principle of the method used?

42

Write down the reactions taking place in Blast furnace related to the metallurgy of iron in the temperature range 500-800 K.

43

Give two requirements for vapour phase refining.

44 Note

Write the chemical reactions involved in the extraction of gold by cyanide process. Also give the role of zinc in the extraction.

45

Match the items of Column I with items of Column II and assign the correct code:

Code :

A. A (1) B (2) C (3) D (4)

B. A (2) B (4) C (5) D (3)

C. A (2) B (3) C (4) D (5)

D. A (4) B (5) C (3) D (2)

46

Match the items of Column I with the items of Column II and assign the correct code :

Code :

47

Match items of Column I with the items of Column II and assign the correct code :

Code :

48

Match the items of Column I with the items of Column II and assign the correct code :

Code :

49

Match the items of Column I with items of Column II and assign the correct code :