Advertisements
Advertisements
प्रश्न
The process of leaching alumina, using sodium carbonate is called
- Bayer's process
- Decomposition
- Cyanide process
- Hall's process
Advertisements
उत्तर
Hall’s process
In Hall’s process, the ore and sodium carbonate are fused to convert aluminium oxide into soluble sodium meta aluminate.
APPEARS IN
संबंधित प्रश्न
Write the reactions involved in the zone of reduction in blast furnace during extraction of iron.
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?
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?
What is the role of coke in the extraction of iron from its oxides?
What is the role of silica in the extraction of copper?
Which form of the iron is the purest form of commercial iron?
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:
Galvanization
The chemical formula of willemite is __
(a) ZnS
(b) ZnCO3
(c) ZnO
(d) Zn2SiO4
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]
Describe the role of the cryolite in the extraction of aluminium from pure alumina.
Metals which occur in their native state in nature:
The sulphide ore of iron 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.
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.
Identify a mineral for the major source of boron from the following list?
The important ore of iron is:-
In the thermite process, the reducing agent is:
Metal always found in Free State is
Which of the following is not an ore of magnesiuim?
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.
Calamine and Malachite, respectively, are the ores of ______.
The ore that contains both iron and copper is ______.
