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प्रश्न
The process of leaching alumina, using sodium carbonate is called
- Bayer's process
- Decomposition
- Cyanide process
- Hall's process
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उत्तर
Hall’s process
In Hall’s process, the ore and sodium carbonate are fused to convert aluminium oxide into soluble sodium meta aluminate.
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संबंधित प्रश्न
Purification of aluminium by electrolytic refining is carried out by
(a)Hoope process
(b)Hall process
(c)Baeyer process
(d)Serperck process
What is the role of cryolite in the extraction of aluminium?
What is the role of limestone in the extraction of iron from its oxides?
What is the role of coke in the extraction of iron from its oxides?
Indicate the principle behind the method used for the refining of zinc.
Which form of the iron is the purest form of commercial iron?
Define Leaching.
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
Copper has the face centred cubic structure. The coordination number of each ion is:
In the extraction of zinc from zinc blende:
(i) Give an equation to show how zinc oxide is converted to zinc.
(ii) How is impure zinc finally electro-refined?
Metals which occur in their native state in nature:
Carbonate 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.
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?
Write the chemical reactions involved in the extraction of gold by cyanide process. Also give the role of zinc in the extraction.
In the thermite process, the reducing agent is:
In the electrolytic process for the extraction of aluminium the electrolyte is:-
Metal always found in Free State is
When compared to ΔG° for the formation of Al2O3 ΔG° for the formation of Cr2O3 is
In the extraction of iron, the slag produce is
Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true?
Match List I with List II.
| List - I | List - II | ||
| a. | Siderite | I. | FeCO3 |
| b. | Malachite | II. | CuCO3 · Cu(OH)2 |
| c. | Sphalerite | III. | ZnS |
| d. | Calamine | IV. | ZnCO3 |
Choose the correct answer from the option given below.
