Aluminium is obtained by
reducing Al2O3 with coke
electrolysing Al2O3 dissolved in Na3AlF6
reducing Al2O3 with chromium
heating alumina with cryolite
Gravity separation process is used for the concentration of:
calamine
haematite
chalcopyrite
bauxite
Which of the following is not an ore of magnesium?
Magnesite
Dolomite
Gypsum
Carnallite
C.
Gypsum
Gypsum or CaSO4.2H2O is an ore of calcium.
Dolomite or CaCO3.MgCO3; Magnesite or MgCO3 and Carnallite or KCl.MgCl2.6H2O are the ores of magnesium.
In Mc Arthur forest method, silver is extracted from the solution of Na[Ag(CN)2] by the use of:
Fe
Mg
Cu
Zn