Blister copper is melted in a furnace then stirred with green wooden logs. The purpose is
to expel the soluble gases out of the blister copper
to bring the impurities on the surface to oxidise them
to increase the carbon in copper
to reduce the metallic oxide impurities by the hydrocarbon gases coming out of the log during the process
During smelting of an ore an additional substance is added to make the impurities fusible. The name of it is
Slag
mud
gangue
flux
In the metallurgy of which of the following cupellation process is used?
Copper
Silver
Iron
Aluminium
Cryolite is used in the electrolytic extration of aluminium
to obtain more aluminium
to decompose bauxite
to protect anodes
as a reducing agent
B.
to decompose bauxite
Cryolite is used in the electrolytic extraction of aluminium to decompose bauxite.
3NaF + AlF3
AlF3 Al3+ + 3F-
At cathode
Al3+ + 3e- → Al (l)
At anode
2Al2O3 + 12F- → 4AlF3 + 6O2-
C (s) + O2- → CO (g) + 2e-
C (s) + 2O2- → CO2 (g) + 4e-
In electrorefining of metal, the impure metal is made the anode and a strip of pure metal the cathode during the electrolysis of an aqueous solution of a complex metal salt. This method cannot be used for refining of
silver
copper
aluminium
zinc
Match List I with List II and select the correct answer using the codes given below the lists.
List I (Metals) | List II ( Name of refining process) | ||
(P) | Ni | (1) | Distillation |
(Q) | Cu | (2) | Electrolysis |
(R) | Cr | (3) | Mond process |
(S) | Hg | (4) | Aluminothermic process |
(P) | (Q) | (R) | (S) |
(3) | (2) | (4) | (1) |
(P) | (Q) | (R) | (S) |
(2) | (3) | (1) | (4) |
(P) | (Q) | (R) | (S) |
(4) | (1) | (2) | (3) |
(P) | (Q) | (R) | (S) |
(1) | (4) | (3) | (2) |
Froth floatation process is used for the concentration of which one?
Horn silver
Haematite
Bauxite
Cinnabar