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प्रश्न
Mention names and formulae of two ores of alumunium.
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उत्तर
Gibbsite or hydragillite : Al2O3.3H2O
Bauxite Al2O3.2H2O
Dispore Al2O3.H2O
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संबंधित प्रश्न
Write the names and chemical formulae of any one ore of zinc.
The process of leaching alumina, using sodium carbonate is called
- Bayer's process
- Decomposition
- Cyanide process
- Hall's process
Write the reactions involved in the zone of reduction in blast furnace during extraction of iron.
Fe2O3 is reduced to spongy iron near the top of blast furance by
(A) H2
(B) CaO
(C) SiO2
(D) CO
Draw neat and labelled diagram of Bessermer converter used in the extraction of copper.
Purification of aluminium by electrolytic refining is carried out by
(a)Hoope process
(b)Hall process
(c)Baeyer process
(d)Serperck process
In the extraction of Al, impure Al2O3 is dissolved in conc. NaOH to form sodium aluminate and leaving impurities behind. What is the name of this process?
Which form of the iron is the purest form of commercial iron?
Name the method used for refining of copper metal.
Differentiate between “minerals” and “ores”.
Write the names and chemical formulae of any ‘two’ minerals of aluminium.
Which among the following minerals does NOT contain aluminium?
(a) Cryolite
(b) Siderite
(c) China clay
(d) Corundum
Explain the following methods to protect metals from corrosion:
Passivation
Why does copper obtained in the extraction from copper pyrites have a blistered appearance?
The chemical formula of willemite is __
(a) ZnS
(b) ZnCO3
(c) ZnO
(d) Zn2SiO4
How will you convert the following:
[Ag(CN)2]− to Ag
The most abundant metal on earth is:
Which of the following options are correct?
(i) Cast iron is obtained by remelting pig iron with scrap iron and coke using hot air blast.
(ii) In extraction of silver, silver is extracted as cationic complex.
(iii) Nickel is purified by zone refining.
(iv) Zr and Ti are purified by van Arkel method.
Which of the following reactions occur during calcination?
(i) \[\ce{CaCo3 -> CaO + CO2}\]
(ii) \[\ce{2FeS2 + 11/2 O2 -> Fe2O3 + 4SO2}\]
(iii) \[\ce{Al2O3. {x}H2O -> Al2O3 + {x}H2O}\]
(iv) \[\ce{ZnS + 3/2 O2 -> ZnO + SO2}\]
The main reactions occurring in blast furnace during extraction of iron from haematite are:
(i) \[\ce{Fe2O3 + 3CO -> 2Fe + 3CO2}\]
(ii) \[\ce{FeO + SiO2 -> FeSiO3}\]
(iii) \[\ce{Fe2O3 + 3C -> 2Fe + 3CO}\]
(iv) \[\ce{CaO + SiO2 -> CaSiO3}\]
Although carbon and hydrogen are better reducing agents but they are not used to reduce metallic oxides at high temperatures. Why?
When a strip of metallic zinc is placed in an aqueous solution of copper nitrate the blue colour of the solution disappear due to formation of
The important ore of iron is:-
In the thermite process, the reducing agent is:
Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true?
Pyrolusite is ______.
