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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
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
Fe2O3 is reduced to spongy iron near the top of blast furance by
(A) H2
(B) CaO
(C) SiO2
(D) CO
Mention names and formulae of two ores of alumunium.
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?
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?
Indicate the principle behind the method used for the refining of zinc.
Which form of the iron is the purest form of commercial iron?
Write the names and chemical formulae of any ‘two’ minerals of aluminium.
Explain the following methods to protect metals from corrosion:
Galvanization
Draw a neat, well labelled diagram of electrolytic cell for extraction of aluminium
What happens when a nickel rod is dipped into a copper sulphate solution? Justify your answer.
[\[\ce{E{^{\circ}_{Ni^{+2}/Ni}}}\] = − 0.25 V and \[\ce{E{^{\circ}_{Cu^{+2}/Cu}}}\] = +0.34 V]
How will you convert the following:
[Ag(CN)2]− to Ag
Metals which occur in their native state in nature:
Which among the following statement is correct?
The most abundant metal on earth is:
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) \[\ce{ZnS + 3/2 O2 -> ZnO + SO2}\]
Write the chemical reactions involved in the extraction of gold by cyanide process. Also give the role of zinc in the extraction.
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:
Metal always found in Free State is
Native silver metal forms a water solution complex with dilute solution of Na CN in the presence of
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?
Pyrolusite is ______.
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.
