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प्रश्न
Fe2O3 is reduced to spongy iron near the top of blast furance by
(A) H2
(B) CaO
(C) SiO2
(D) CO
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उत्तर
(d) CO
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संबंधित प्रश्न
The process of leaching alumina, using sodium carbonate is called
- Bayer's process
- Decomposition
- Cyanide process
- Hall's process
What is the chemical composition of malachite?
- CuO . CuC03
- Cu(OH)2 CuC03
- CuO.Cu(OH)2
- Cu2O . Cu(OH)2
Write chemical formulae of the following ores :
(a) Calamine
(b) Haematite
(c) Magnetite
(d) Corundum
Out of C and CO, which is a better reducing agent at the lower temperature range in the blast furnace to extract iron from the oxide ore?
Mention names and formulae of two ores of alumunium.
Describe the roles of the following: SiO2 in the extraction of copper from copper matte
Name the method used for refining of copper metal.
Differentiate between “minerals” and “ores”.
Which among the following minerals does NOT contain aluminium?
(a) Cryolite
(b) Siderite
(c) China clay
(d) Corundum
What is the role of the following compound-
SiO2 in the extraction of copper from copper pyrites?
Copper has the face centred cubic structure. The coordination number of each ion is:
Describe the role of the cryolite in the extraction of aluminium from pure alumina.
How will you convert the following:
[Ag(CN)2]− to Ag
What are the differences between minerals and ores?
Give the uses of zinc.
Metals which occur in their native state in nature:
The sulphide ore of iron is ____________.
When copper ore is mixed with silica, in a reverberatory furnace copper matte is produced. The copper matte contains ______.
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.
In the extraction of aluminium by Hall-Heroult process, purified \[\ce{Al2O3}\] is mixed with \[\ce{CaF2}\] to:
(i) lower the melting point of \[\ce{Al2O3}\].
(ii) increase the conductivity of molten mixture.
(iii) reduce \[\ce{Al^{3+}}\] into \[\ce{Al(s)}\].
(iv) acts as catalyst.
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?
Identify a mineral for the major source of boron from the following list?
In the thermite process, the reducing agent is:
Which of the following is not ore of aluminium?
Which of the following is not an ore of magnesiuim?
In the extraction of iron, the slag produce is
