Three most occuring elements in the earth crust are :
An ore containing the impurity of FeCr2O4 is concentrated by :
FeCr2O4 due to magnetic nature is separated by magnetic seperation
A piece of steel is heated until redness and then plunged into cold water or oil. This treatment of steel makes it :
Give the correct order of initials T or F for following statements. Use T if statement is true and F if it is false:
(i) Cu metal is extracted from its sulphide ore by reduction of Cu2O with FeS.
(ii) An ore of Tin containing FeCrO4 is concentrated by magnetic separation method.
(iii) Auto reduction process is used in the extraction Cu & Hg.
(iv) Cassiterite and Rutile are oxide ores of the metals.
(i) Cu2O + FeS → Cu2S + FeO
(ii) AsFeCrO4 is magnetic in nature.
In the extraction of aluminium :
Process X : applied for red bauxite to remove iron oxide (chief impurity)
Process Y : (Serpeck's process) : applied for white bauxite to remove Z (chief impurity) then, process X and impurity Z are :
Hoop's process of purification of aluminium involves formation of layers during electrolysis. It involves :
Metallurgical process of zinc involves roasting of zinc sulphide followed by reduction. Metallic zinc distills over as it is volatile and impurities like Cu, Pd and Fe gets condensed. The crude metal obtained is called spelter which may be purified by :
The Crude metallic Zn can be purified by elctrolysis process or by distillation.
Calcination and roasting process of reduction of ores to their oxides are beneficial :
In the extraction of copper, the reaction which takes place in Bessemer converter is :
The reaction which takes place in Besseiner converter during extration of Cu
Extraction of silver from argentiferrous lead (Pb + Ag) involves :
In the manufacturing of metallic sodium by fused salt–electrolysis method (Down's process), small amount of CaCl2 that added is known as auxiliary electrolyte and in used to :
CaCl2 is added to improve electrical conductivity and it also decrease the m.p. of NaCl.
Metal(s) which does/do not form amalgam is/are :
Fe and Pt does not form amalgam.
Auto reduction process is used in extraction of
Auto reduction is used
For Cu, Hg, Sn
Match column–I and column–II and select the correct answer using the codes given below the lists:
Cyanide process → Ag and Au
floatation process → Dressing of Hgs
Electrolytic reduction → Extraction of Al
Zone refining → Ultrapure of Ge,
Match column–I with column–II and select the correct answer using the codes given below :
(I) Iron and Cu → Bessemerisation
Assertion : Sulphide ores are concentrated by froth floatation process.
Reason : Pine oil acts as a frothing agent in froth floatation process.
Sulphide are is concentrated by froth floatation process.
Assertion : Platinum and gold occur in native state in nature.
Reason : Platinum and gold are noble metals.
Pt and Au are Noble metals.
Assertion : Wolframite impurities are separated from cassiterite by electromagnetic separation.
Reason : Cassiterite being magnetic is attracted by the magnet and forms a separate heap.
Wolframite/FewO4 + MnWO4 (little) is the magnetic impurity in the stone or cassiterite (SnO2)
Assertion : In smelting, roasted ore is heated with powdered coke in presence of a flux.
Reason : Oxides are reduced to metals by C or CO. Impurities are removed as slag.
Assertion : Al is used as a reducing agent in aluminothermy.
Reason : Al has a lower melting point than Fe, Cr and Mn.
In the commerical electrochemical process for aluminium extraction, the electrolyte used as :
Electrolyte is Al2O3 + Na3AlF6 (molten)
The chemical process in the production of steel from haematite ore involve:
[JEE 2000 Qualifying]
Electrolytic reduction of alumina to aluminium by Hall-Heroult process is carried out :
[JEE 2000 Qualifying]
Cryolite forms a Melt with Lower melting point
The chemical composition of "slag" formed during the smelting process in the extraction of copper is :
Which of the follwoing processes is used in extractive metallurgy of magnesium?
[JEE 2002 Qualifying]
Mg is obtained by electrolysis of its fused soet.