19,000+ solved questions for JEE Advanced, JEE Mains, NEET & IChO — with answers and expert explanations.
Roasting or ores is done
Which one of the following reactions represents a calcination reaction?
Calcination of ores involves heating the ore below its fusion temperature
By which of the following processes is an oxide ore reduced to the free metal?
A flux is often added to remove impurities from an ore in a blast furnace. In the reaction CaO + SiO2-> CaSiO3 the slag and the flux are
Which one of the following is not a basic flux?
Flux is used to remove:
Which one of the following ores is best concentrated by froth floatation method?
In the froth floatation process for benefaction of the ores, the ore particles float because
Which of the following benefaction processes is used for the mineral, Al2O3.2H2O?
Chemical leaching is useful in the concentration of:
Wolframite (FeWO4), present as an impurity in cassiterite (SnO2), can be removed by the process of
Which of the following statements, about the advantage of roasting of sulphide ore before reduction is not true? (RPMT 2007)
Among the metals Cr, Fe, Mn, Ti, Ba and Mg, the one that cannot be obtained by reduction of metal oxide by aluminium is (RPMT 2007)
The magnetite ore is (AIPMT 2007)
Blister copper is: (AIPMT 2007)
Sulphide ores of metals are usually concentrated by Froth floatation process. Which one of the following sulphide ores offers an exception and is concentrated by chemical leaching? (AIPMT 2007)
Gº vs T plot in the Ellingham’s diagram slopes downwards for the reaction. (RPMT 2006) (a) Mg+ O MgO -> (b) 2Ag+ O Ag O -> (c) C O CO -> (d) CO O CO ->
Which of the following reactions taking place in the blast furnace during extraction of iron is endothermic? (RPMT 2006)
Consider the following reaction at 1000ºC. (AIPMT 2006) I. - Zn(s)+ O (g) ZnO(s);ΔG°=-360KJmol -> II. - C(gr)+ O (g) CO(g);ΔG°=-460KJmol -> Choose the correct statement at 1000ºC
The ore having two different metal atoms is (AIPMT 2006)
330 350K Ni 4CO Ni CO -> 450 470K Ni CO Ni 4CO -> The above reactions are of the purification of Ni by
The major role of fluorspar (CaF2) which is added in small quantities in the electrolytic reduction of alumina dissolved in fused cryolite (Na3AlF6) is
Aluminium is extracted by the electrolysis of
In the context of the Hall - Heroult process for the extraction of Al, which of the following statements is false?