Tiêu đề 6.GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS.pdf ✅

User Restrictions: Not authorized to transfer to any third party, Not authorized to go for any resale of this document without permission. Document is protected from being unauthorized use, for any help please contact Mr. SEKHAR , +919206306398. We are not responsible for lose of data while deprotecting the document without any permission from author. Use only for question paper preparation, worksheet preparation... 6.GENERAL PRINCIPLES AND PROCESSES OF ISOLATION OF ELEMENTS Single Correct Answer Type 1. Extraction for zinc from zinc blende is achived by a) Electrolytic reduction b) Roasting following by reduction with carbon c) Roasting followed by reduction with another metal d) Roasting followed by self-reduction 2. The forth-floatation process is based upon a) The difference in the specific gravity of ore and gangue particles b) The magnetic properties of gangue and ore c) Preferential wetting of gangue perticles by oil d) The solubility of ore particles in suitable regent 3. Formula of magnetite is a) Fe3O4 b) Fe2O3 c) FeS2 d) FeCO3 4. Cinnabar is an ore of a) Pb b) Hg c) Cu d) Zn 5. Copper pyrites is concentrated by a) Gravity method b) Forth floatation process c) Electromagnetic method d) All of these 6. The method of concentrating the ore which makes use of the difference in density between ore and impurities is called a) Leaching b) Liquation c) Levigation d) Magnetic separation 7. The method of zone refining of metals is based on the principle of a) Greater noble character of the solid metal than that of the impurity b) Greater solubility of the impurity in the molten state then in the solid c) Greater mobility of the pure metal than that of impurity d) Higher malting point of the impurity that of the pure metal 8. An example of an oxide is a) Zinc blende b) Bauxite c) Feldspar d) Malachite 9. Forth floatation process for the concentration of the ores is an illustration of the practical application of a) Adsorption b) Sedimentation c) Coagulation d) Absorption 10. In the metallurgy of iron, when CaCO3 is added to blast furnace, calcium ion appears as a) Slag b) Gangue c) CaO d) Metallic Ca 11. Which of the following ores does not represent the ores of iron? a) Cassiterite b) Limonite c) Haematite d) Magnetite 12. Apatite is an ore of a) Fluorine b) Chlorine c) Bromine d) iodine 13. Which ore contain both iron and copper?
User Restrictions: Not authorized to transfer to any third party, Not authorized to go for any resale of this document without permission. Document is protected from being unauthorized use, for any help please contact Mr. SEKHAR , +919206306398. We are not responsible for lose of data while deprotecting the document without any permission from author. Use only for question paper preparation, worksheet preparation... a) Cuprite b) Chalococite c) Chalcopyrite d) malachite 14. Which of the following substances can be used for drying gases? a) CaO b) NaHCO3 c) CaCO3 d) Na2CO3 15. The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the hall process is (Atomic mass of Al=27) a) 180kg b) 270 kg c) 540 kg d) 90 kg 16. In blast furnace, iron oxide is reduced by a) Silica b) Carbon c) Limestone d) CO 17. Willemite is a) Zn2SiO4 b) H2ptCl6 c) ZnO d) ZnOFe2O3 18. In the modern blast furnaces, the charge consists of a mixture of a) Iron pyrites + bituminous coal b) Hydrated iron oxides +dolomite + coke c) Calcined iron oxides + limestone + coke d) Calcined iron oxides + lime + anthracite coal 19. Which is not a mineral of aluminium? a) Corundum b) Anhydrite c) Diaspore d) Bauxite 20. In alumino-thermite process, aluminium is used as a) Reducing agent b) Oxidizing agent c) Solder d) Flux 21. Auto-reduction process is used in the extraction of a) Cu and Hg b) Zn and Hg c) Cu and Al d) Fe and Pb 22. The temperature of the slag zone in the metallurgy of iron using blast furnace is a) 1200 − 1500°C b) 1500 − 1600°C c) 400 − 700°C d) 800 − 1000°C 23. All ores are minerals, while all minerals are not ores because a) Minerals are complex compounds b) The minerals are obtained from mines c) The metal cannot be extracted economically from all the minerals d) All of the above are correct 24. In order to refine blister copper, it is melted in a furnace and is stirred with green logs of wood. The purpose is a) To expel the dissolved gases in blister copper b) To bring the impurities to surface and oxidize them c) To increase the carbon content of copper d) To reduce the metallic oxide impurities with hydrocarbon gases liberated from the wood 25. Argentite is a mineral of a) Gold b) Silver c) Copper d) Platinum 26. An ore of tin containing FeCrO4 is concentrated by a) Electrostatic method b) Gravity separation c) Magnetic separation d) Forth floatation
User Restrictions: Not authorized to transfer to any third party, Not authorized to go for any resale of this document without permission. Document is protected from being unauthorized use, for any help please contact Mr. SEKHAR , +919206306398. We are not responsible for lose of data while deprotecting the document without any permission from author. Use only for question paper preparation, worksheet preparation... 27. To dissolve argentite ore which of the following is used? a) Na[Ag(CN) 2 b) NaCN c) NaCl d) HCl 28. Titanium containing mineral found in our country is a) Bauxite b) Chalcopyrites c) Elmanite d) dolomite 29. Metals are good conductors of electricity because they contain a) Ionic bonds b) A network structure c) Very few valence electrons d) Free electrons 30. Bronze is a mixture of a) Pb+ Sn b) Cu+ Sn c) Cu+ Zn d) Pb+ Zn 31. Thomas slag is a) Ca3 (PO4 )2. 2H2O b) Ca3 (PO4 )2. CaSiO3 c) MgSiO3 d) CaSiO3 32. The process of heating the ore strongly in excess of air so that the volatile impurities are removed and the ore is changed to oxide is known as a) Leaching b) Roasting c) Calcinations d) Froth floatation 33. Heating mixture of Cu2O and Cu2S will give a) Cu2SO3 b) CuO + CuS c) Cu + SO3 d) Cu + SO2 34. Stainless steel has iron and a) Cr b) Cu c) Co d) Zn 35. In metallurgy, flux is a substance used to convert a) Soluble impurities to insoluble impurities b) Infusible impurities to fusible material c) Fusible impurities to infusible impurities d) Mineral into silicate 36. Formula for agate is a) Na2SiO3 b) K2O. SiO2.Al2O2 c) SiO2 d) CaF2 37. Bauxite ore is made up of Al2O3 + SiO2 + Tio2 + Fe2O3 This ore is treated with conc NaOH solution at 500 K and 35 bar pressure for few hours and filtered when hot. In the filtrate, the species present are a) NaAl(OH)4 only b) Na2Ti(OH)6 only c) NaAl(OH)4 snd Na2SiO3both d) Na2SiO3 only 38. Which of the following mineral does not contain Al? a) Fluorspar b) Cryolite c) Mica d) Feldspar 39. van-Arker method of purification of metals involves converting the metal to a a) Volatile stable compound b) Non-volatile stable compound c) Volatile unstable compound d) None of the above 40. The electrolytic method of reduction is employed for the preparation of metals that a) Are strongly electropositive b) Are weakly electropositive c) Are moderately electropositive d) From oxides 41. Cassiterite is an ore of a) Sb b) Mn
User Restrictions: Not authorized to transfer to any third party, Not authorized to go for any resale of this document without permission. Document is protected from being unauthorized use, for any help please contact Mr. SEKHAR , +919206306398. We are not responsible for lose of data while deprotecting the document without any permission from author. Use only for question paper preparation, worksheet preparation... c) Sn d) Ni 42. When copper pyrites is roasted in excess if air, a mixture of CuO + FeO is formed .FeO is present as impurities. This can be removed as slag during reduction of CuO. The flux added to from slag is a) SiO2 which is an acid flux b) Lime stone, which is a basic flux c) SiO2,which is basic flux d) CaO, which is basic flux 43. Metal occur in the native from because of their a) High electronegativity b) High reactivity c) Low reactivity d) Low density 44. Load stone is one ore of a) Iron b) Lead c) Silicon d) Tin 45. Which metal is extracted by electrolytic reduction method? a) Cu b) Al c) Ag d) Fe 46. Among the following statements, the incorrect one is a) Calamine and siderite are carbonates b) Malachite and azurite are ores of copper c) Argentite and cuprite are oxides d) Zinc blende and pyrites are sulphides 47. CaO act as ... flux a) Neutral b) Acidic c) Basic d) Both (a) and (b) 48. The substance added in water in the forth floatation process is a) Pine oil b) Coconut oil c) Soap powder d) None of these 49. A substance which reacts with gangue to form fusible material is called a) Flux b) Slag c) Catalyst d) Ore 50. During the process of electrolytic refining of copper, some metals present as impurity settle as ‘anode mud’. These are a) Fe and Ni b) Ag and Au c) Pb and Zn d) Se and Ag 51. One of the following metals forms a volatile compound and this property is taken advantage for its extraction. This metals is a) Cobalt b) Iron c) Tungsten d) Nickel 52. Which is statement is incorrect? a) Galena is an ore of Pb b) Electrostatic separation is used for lead sulphide c) Ore is heated strongly, above its melting point in roasting d) Silica acts as acidic flux 53. Cassiterite is concentrated by a) Liquation b) Floatation c) Electromagnetic separation d) Levigation 54. Which of the following is not ore? a) Zinc blende b) Malachite c) Bauxite d) Pig iron 55. Thermite process is used in reduction of a) Crl2O3 b) Al2O3