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#### Metallurgy Important Question Paper

12th Standard EM

Reg.No. :
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Chemistry

Time : 01:00:00 Hrs
Total Marks : 50
5 x 1 = 5
1. Bauxite has the composition

(a)

Al2O3

(b)

Al2O3nH2O

(c)

Fe2O3.2H2O

(d)

None of these

2. Roasting of sulphide ore gives the gas (A).(A) is a colourless gas. Aqueous solution of (A) is acidic. The gas (A) is

(a)

CO2

(b)

So3

(c)

SO2

(d)

H2S

3. Which one of the following reaction represents calcinations?

(a)

$2Zn+{ O }_{ 2 }\rightarrow 2ZnO$

(b)

$2ZnS+3O_{ 2 }\rightarrow 2ZnS+3O_{ 2 }\rightarrow 2ZnO_{ 2 }\rightarrow 2ZnO+2SO_{ 2 }$

(c)

$MgCO_{ 3 }\rightarrow MgO+CO_{ 2 }$

(d)

Both (a) and (c)

4. Which of the following is not a mineral of aluminium?

(a)

Bauxite

(b)

Cryolite

(c)

China clay

(d)

Malachite

5. Which of the following is commonly used to produce foam in froth floatation process?

(a)

Pine oil

(b)

Cresol

(c)

NaCN

(d)

Xanthate

6. 5 x 2 = 10
7. What is the difference between minerals and ores?

8. What is the role of Limestone in the extraction of Iron from its oxide Fe2O3?

9. What is metallurgy?

10. Why should we have a ecofriendly metallurgical process?

11. Name some elements that occur as native elements.

12. 5 x 3 = 15
13. Explain zone refining process with an example using the Ellingham diagram given below

14. Give the uses of zinc.

15. What is gravity separation? (or)
Explain hydraulic washing?

16. What is cyanide leaching? Give an example

17. What is cementation?

18. 4 x 5 = 20
19. The selection of reducing agent depends on the thermodynamic factor: Explain with an example.

20. Give the limitations of Ellingham diagram

21. Explain froth flotation, with diagram.

22. In the extraction of copper, explain the smelting process.