METALLURGY- 2

Questions carrying one mark:

1.  State Nernst distribution law.

2.  Name the type of iron which cannot be welded?

3.  What is argentiferrous lead?

4.  What is distribution Coefficient?

5.  What is the maximum amount of silver present in argentiferrous lead?

6.  What is the partition coefficient of silver in molten zinc and molten lead?

7.  What is Ellingham diagram?

8.  Give the relationship between solubilities of solute and distribution coefficient?

9.  How does the stability of metal oxides vary with rise in temperature?

10. Give the name of one ore of iron and give its composition.

11. Write the formula of ruby silver.

12. Name a metal which can be extracted using blast furnace.

13. State the name and composition of carbonate ore of iron?

14. Give the compositions of the charge that is fed into the blast furnace during the metallurgy of iron.

15. Name the flux used in the metallurgy of iron.

16. What is the trend in the Ellingham diagram for the formation of carbon monoxide?

17. Why limestone is used in the metallurgy of iron?

18. Give the chemical composition of the slag formed during the metallurgy of iron.

19. During the metallurgy of iron in which form does the calcium ion end up?

20. At the top of the blast furnace which reducing agent reduces iron oxide to spongy iron?

21. The oxides of Hg and Ag are unstable why?

22. Name the reducing agent used for reducing iron oxide in the blast furnace.

23. Name the zone in the blast furnace where the temperature maximum.

24. Below 983K, which is better reducing agent carbon or carbon monoxide?

Question carrying two marks:

1.  Give the principle behind Parke’s process for desilverisation of lead.

2.  Illustrate , with an example ,Distribution law.

3.  With the help of Ellingham diagram explain why metal oxides are unstable at higher temperatures.

4.  How is the relative tendency of oxidation of various metals determined by Ellingham diagram ?

5.  Curves in Ellingham diagram are straight lines ? Why so?

6.  Give the reason why carbondoes not act as a reducing agent for ferric oxide in metallurgy of iron even though a mixture of carbon and ferric oxide is present in the blast furnace.

7.  With the help of Ellingham diagram explain why

a>aluminium is used as a reducing agent in the metallurgy of chromium

b>carbon cannot be used as a reducing agent for reducing chromic acid at low temperature.

c>chromium does not reduce aluminium oxide to aluminium but aluminium can reduce chromic acid.

d>carbon monoxide acts as a reducing agent in the production of cast iron from haematite.

e>at very high temperature even though carbon can reduce all metal oxides to metals it is not preferred as a reducing agent.

f>oxides of mercury and silver can be thermally decomposed at low temperatures.

8.  Draw a neat labeled diagram of the blast furnace and explain the parts and zones present.

9.  Explain cupellation.

10.       Describe the reaction that occur in the blast furnace during the extraction of iron.

11.       What are the roles played by limestone and coke in the metallurgy of iron?

Question carrying three or four marks

      1.Describe parke’s process of desilverisation of lead.

      2.Explain the salient features of Ellingham diagrams.

3.With the help of Ellingham diagram explain the use of carbon and carbon monoxide as reducing agents in metallurgy.

4.Explain with a example,the selection of reducing agent for a metal oxide based on Ellingham diagram.

5.How is cast iron manufactured from haematite using blast furnace?