Metallurgy

Published on December 2016 | Categories: Documents | Downloads: 64 | Comments: 0 | Views: 284
of 5
Download PDF   Embed   Report

Comments

Content

ANDHERI / VILEPARLE / DADAR/CHEMBUR/THANE/CHURCHGATE/NERUL/MIRA ROAD, Tel: 2624 5209/ 2624 5223

METALLURGY TEST 1. Which method of purification is represented by the following equation o o 70 C → Ni(CO)4   180 C → Ni + 4CO Ni + 4CO    (A) van Arkel (B) zone refining (C) mond process White lead is (A) Pb(OH)2.PbCO3 (B) 2PbCO3.Pb(OH)2 (C) Pb(OH)2.Pb(CH3COO)2

(D) cupellation (D) PbCO3.PbO (D) SiO2 and CuO (D) MgO

2. 3. 4.

The common impurities present in the bauxite ore are (A) Fe2O3 and CuO (B) Fe2O3 and PbO (C) Fe2O3 and SiO2 Which of the following is not a basic flux? (A) CaCO3 (B) CaO (C) SiO2

5. 6. 7. 8.

Mac-Aurthur forrest process (Cyanide process) is used for the extraction of (A) Zn (B) Cu (C) Fe (D) Ag Calcination is used in metallurgy to remove (A) H2O and H2S (B) H2O and CO2 Cupric oxide is reduced to copper by (A) H2 (B) C Froth floatation process is based on (A) specific gravity of the ore particle (C) wetting properties of the ore particle Poling process is used (A) for the removal of Cu2O from Cu (C) for the removal Fe2O3 from Fe (C) CO2 and H2S (C) CO (D) All of these (B) magnetic properties of the ore particle (D) electrical property o the ore particle (B) for the removal of Al2O3 from Al (D) in all the above (D) H2O and H2S

9.

10.

Van Arkel method of purification of metals involves converting the metal to a (A) Volatile stable compound (B) Volatile unstable compound (C) non volatile stable compound (D) none of the above The metal obtained by self reduction process is (A) Cu (B)Hg (C) Pb (D)All the above

11. 12.

Which process is not used in purification of bauxite (A) Hall’s method (B) bauxite’s method (C) Serpeks method (D) Franklands method The process of calcination and roasting are carried out in (A) Blast furnace (B) Muffle furnace (C) Reverbaratory furnace (D) Open hearth furnace Which of the following process is used in the extractive metallurgy of magnesium? (A) Fused salt electrolysis (B) Self reduction (C) Aqueous solution electrolysis (D) Thermite reaction

13.

14.

15.

Which of the following statements is correct regarding the slag obtained during the extraction of a metal like copper or iron? (A) The slag is lighter and has higher melting point than the metal. (B) The slag is lighter and has lower melting point than the metal. (C) The slag is heavier and has higher melting point than the metal. (D) The slag is heavier and has lower melting point than the metal. The ore carnallite is represented by structure (A) Na3AlF6 (B) Na2Al2O3

16.

(C) Fe3O4

(D) KCl.MgCl2.6H2O

17.

In order to refine ‘blister copper’ it is melted in a furnance and is stirred with green logs of wood. The purpose is (A) to increase the carbon content of copper. (B) to bring the impurities to surface and oxidize them. (C) to reduce the metallic oxide impurities with hydrocarbon gasses liberated from the wood. (D) to expel the dissolved gases in blister copper. Pb and Sn are extracted from their chief ore respectively by (A) Carbon reduction and self reduction (B) Self reduction and carbon reduction (C) Electrolysis and self reduction (D) Self reduction and electrolysis Which of the following statement is incorrect? (A) Arsenic can be obtained by thermal decomposition of AsH 3. (B) Copper can be displaced from solution by adding iron to it. (C) Al can be used as reducing agent for extracting Mn from Mn 3O4. (D) Below 710°C, formation of CO(g) from C(s) and O2(g) is energetically more favourable. In the Hall’s process for extraction of Al, the ore is fused with: (A) NaHCO3 (B) Na2CO3 (C) NaF (D) Na3AlF6

18.

19.

20. 21. 22. 23. 24.

Of the following metals the ones which cannot be obtained by electrolysis of the aqueous solution of their salts. (A) Ag (B) Mg (C) Cu (D) Al Which of the following metals can be obtained by reducing its metal oxide using aluminium? (A) Ca (B) Fe (C) Mg (D) Cr In the equation, X + CN− + H2O + O2 → [X(CN)2]− + 4OH− ‘X’ can be (A) Au (B) Ag2S (C) Sb (D) As In the given reaction ‘X’ can be Au and Ag 2S. − 4Au + 8CN− + 2H2O + O2 → 4Au(CN ) − 2 + 4OH
− 2Ag2S + 8CN− + 2H2O + O2 → 4Ag(CN) − 2 + 4OH + 2S Which of the following ores is/are oxide ore(s)? (A) Cassiterite (B) Bauxite (C) Cryolite (D) Haematite

25. 26.

Van Arkel method of purification of metals (A) involves converting the metal to a volatile compound. (B) involves converting the metal to a volatile iodide. (C) is used for Zr. (D) involves converting metal to a non-volatile compound. Metallurgy involves steps (A) concentration of ore (C) purification (B) reduction of ore (D) alloy formation

27.

Read the given Comprehension regarding Ellingham diagrams, and answer the following Questions. The metals obtained by the application of smelting, self reduction, electrolytic reduction, amalgamation and Hydrometallurgy methods from the concentration ores are usually impure. The impure metal is thus subjected to some purifying process known as refining in order to remove undesired impurities. Various processes for this are Liquation process, Cupellation, Zone Refining, Bassemerisation, Van Arkel Process, Mond’s Process etc. 28. 29. The metal for which, its property of formation of volatile complex is taken into account for its extraction is: (A) Cobalt (B) Nickel (C) Vanadium (D) Iron Zone refining is based on the principle of: (A) Fractional distillation (C) Fractional crystallization (B) partition coefficient (D) Chromatographic separation

30.

When an impurity in metal has greater affinity for oxygen and is more easily oxidized than the metal itself, then the metal is refined by: (A) Cupellation (B) Zone refining (C) Poling (D) Electrolytic process

31. Van Arkel Process is used for obtaining ultrapure metals. The impure metal is converted into volatile compounds which is then decomposed electrically to get pure metal.
Heating ImpureMetal +I2 → Metal Iodide vapour  →PureMetal +I2 Tunstun Filament

This process is not used for (A) Ti (B) Zn 32. Poling process is used: (A) for the removal of Cu2O from Cu (C) for the removal of Fe2O3 from Fe

(C) Zr

(D) Hf

(B) for the removal of Al2O3 from Al (D) in all the above

33.

Match Column I and II and select the correct answer using the codes given below the lists: Column- I Column-II A. Cyanide process P. Ultrapure Ge B. Floatation process Q. Dressing of HgS C. Electrolytic reduction R. Extraction of Al D. Zone refining S. Extraction of Au Match Column I and II and select the correct answer using the codes given below the lists: Column- I Column-II A. Iron pyrites P. FeS2 B. Fool’s gold Q. Sulphide ore C. Galena R. Fe2O3 D. Haematite S. Concentrated by froth floating process

34.

Read the given Comprehension regarding Ellingham diagrams, and answer the following Questions. The Ellingham diagram plots the Gibbs free energy change (ΔG) for the oxidation reaction versus the temperature. In the temperature ranges commonly used, the metal and the oxide are in a condensed state (liquid or solid) and the oxygen gaseous as M + O2→MO Gases have higher entropy than liquid or solid, hence ΔS is negative for above reaction. Thus if temperature is raised than TΔS become more negative, then ΔG become less negative. So generally ΔG increases with temperature. The free energy changes all follow the straight line unless the materials melt or vaporized In the case of carbon reacting with dioxygen, two reactions are possible: C + O2 → CO2 and 2C+ O2 → 2CO 35. Nearly all the oxides of metals can decomposed on increasing the temperature, which oxide can be easily decomposed? (A) HgO (B) Ag2O (C) Fe2O3 (D) CaO 36. The metal oxide can’t be reduced by the carbon even at 1500 oC (A) Iron (B) Nickel (C) Calcium 37. 38.

(D) Mercury

At what approximate temperature Mg and carbon have equal affinity for oxygen? (A) 1000oC (B) 1500oC (C) 500oC (D) 1800oC At this temperature ∆ G o of the reaction is MgO + C → Mg + CO (A) negative (B) positive (C) zero

(D) Nothing can be said

39.

To make the following reduction process spontaneous, temperature should be MgO + C → Mg + CO (A) < 1200oC (B) > 1200oC (C) < 500oC (D) >500oC but < 1200oC

NAME: ________________________________________________ DATE: ____________________ 1. 2. 3. 4. 5. 6. 7. 8. 9.
A A A A A A A A A B B B B B B B B B C C C C C C C C C D D D D D D D D D

11. 12. 13. 14. 15. 16. 17. 18. 19.

A A A A A A A A A

B B B B B B B B B

C C C C C C C C C

D D D D D D D D D

21. 22. 23. 24. 25. 26. 27. 28. 29.

A A A A A A A A A

B B B B B B B B B

C C C C C C C C C

D D D D D D D D D

31. A B 32. A B 33. (A) P (B) P (C) P (D) P 34. (A) P (A) P (B) P

C C

D D

Q Q Q Q Q Q Q R R R

R R R R S S S

S S S S

35. 36. 37. 38. 39.

A A A A A

B B B B B

C C C C C

D D D D D

10.

A

B

C

D

20.

A

B

C

D

30.

A

B

C

D

(C)

P

Q

R

S

Sponsor Documents

Or use your account on DocShare.tips

Hide

Forgot your password?

Or register your new account on DocShare.tips

Hide

Lost your password? Please enter your email address. You will receive a link to create a new password.

Back to log-in

Close