6. GENERAL PRINCIPLES & PROCESSES OF ISOLATION OF ELEMENTS Objective
6. GENERAL PRINCIPLES & PROCESSES OF ISOLATION OF ELEMENTS
Download 1. Removal of the unwanted materials like sand, clays, etc. from the ore is known as ……., …… Or …….
(A) concentration, dressing, benefaction
(B) separation, refining, gangue
(C) magnetic separation, purification, gangue
(D) washing, refining, amalgamation
Answer тЗТ (A)
2. How do we separate two sulphide ores by froth floatation method ?
(A) By using excess of pine oil
(B) By adjusting proportion of oil to water or using depressant
(C) By using some solvent in which one of the sulphides is soluble
(D) By using collectors and froth stabilisers like xanthates
Answer тЗТ (B)
3. Common impurities present in bauxite are
(A) Cuo
(B) Zno
(C) CaO
(D) SiO2
Answer тЗТ (D)
4. Which of the following ores cannot be concentrated by magnetic separation ?
(A) Haematite
(B) Malachite
(C) Magnetite
(D) Siderite
Answer тЗТ (B)
5. Which of the following metals is extracted using a silica lined convertor ?
(A) Mg
(B) Al
(C) Cu
(D) Zn
Answer тЗТ (C)
6. Which of the following metals cannot be obtained by reduction of its metal oxide by aluminium ?
(A) Cr
(B) Mn
(C) Fe
(D) Mg
Answer тЗТ (D)
7. In metallurgical process, aluminium acts as
(A) an oxidising agent
(B) a reducing agent
(C) acidic flux
(D) basic flux
Answer тЗТ (B)
8. In blast furnace iron oxide is reduced by
(A) silica
(B) carbon monoxide
(C) carbon
(D) lime stone
Answer тЗТ (B)
9. In a thermite process ……. is used as reducing agent.
(A) Zn
(B) Al
(C) Mn
(D) Fe
Answer тЗТ (B)
10. Which of the following slags is produced during extraction of iron ?
(A) CaSiO3
(B) FeSiO3
(C) MgSiO3
(D) ZnSiO3
Answer тЗТ (A)
11. Which of the following reactions takes place at higher temperature range (900 K – 1500 K) in blast furnace ?
(A) 3Fe2O3 + CO тЖТ CO тЖТ 2Fe3O4 + CO2
(B) FeO + CO тЖТ Fe + CO2
(C) Fe3O4 + 4CO тЖТ 3Fe + 4CO2
(D) Fe2O3 + CO тЖТ 2FeO + CO2
Answer тЗТ (B)
12. Which of the following metals cannot be obtained by electrolysis ?
(A) Cr
(B) Na
(C) Ca
(D) Mg
Answer тЗТ (A)
13. In electro-refining of copper, some gold is deposited as
(A) cathode mud
(B) electrolyte
(C) anode mud
(D) cathode
Answer тЗТ (C)
14. Most electropositive metals are obtained from their ores by
(A) autoreduction
(B) smelting with carbon
(C) electrolysis of fused salts
(D) thermal decomposition
Answer тЗТ (C)
15. During the process of electrolytic refining of copper, some metals present as impurity settle as anode mud. These are
(A) Sn and Ag
(B) Pb and Zn
(C) Ag and Au
(D) Fe and Ni
Answer тЗТ (C)
16. A number of elements are available in earth’s crust but most abundant elements are
(A) Al and Fe
(B) Al and Cu
(C) Fe and Cu
(D) Cu and Ag
Answer тЗТ (A)
17. Electrolytic refining is used to purify which of the following metals ?
(A) Cu and Zn
(B) Ge and Si
(C) Zr and Ti
(D) Zn and Hg
Answer тЗТ (A)
18. Dolamite mineral contains
(A) Mg
(B) Al
(C) Ca
(D) K
Answer тЗТ (A)
19. Name important ore of aluminium
(A) Bauxite
(B) Cryolite
(C) Croundum
(D) None
Answer тЗТ (A)
20. NaOH is known as
(A) Caustic soda
(B) Washing soda
(C) Caustic Potash
(D) All
Answer тЗТ (A)
21. The formula of blue vitriol is
(A) CuSO4
(B) CuSO4.5H2O
(C) CaSO4.2H2O
(D) None
Answer тЗТ (A)
Class 12th Chemistry Objective Question English
| S.N | CHEMISTRY OBJECTIVE English Medium |
| 1 | SOLID STATE┬а |
| 2 | SOLUTION |
| 3 | ELECTROCHEMISTRY |
| 4 | CHEMICAL KINETICS |
| 5 | SURFACE CHEMISTRY |
| 6 | GENERAL PRINCIPLES & PROCESSES OF ISOLATION OF ELEMENTS |
| 7 | THE P-BLOCK ELEMENTS |
| 8 | THE D- AND f-BLOCK ELEMENTS |
| 9 | CO-ORDINATION COMPOUNDS |
| 10 | HALOALKANES AND HALOARENES |
| 11 | ALCOHOLS, PHENOLS AND ETHERS |
| 12 | ALDEHYDES, KETONES AND CARBOXYLIC ACIDS |
| 13 | AMINES |
| 14 | BIOMOLECULES |
| 15 | POLYMERS |
| 16 | CHEMISTRY IN EVERYDAY LIFE |
