Ores and concentration methods

27 questions on Ores and concentration methods from the Metallurgy chapter: 6 NEET level, 11 JEE Main, 10 JEE Advanced. Each one opens with its answer and solution.

• Which of the following is the chief ore of zinc? NEET level
• The formula of siderite, an ore of iron, is NEET level
• Froth flotation is the most suitable method for concentrating NEET level
• Calcination of an ore involves heating it NEET level
• Cassiterite, SnO2, contains wolframite, FeWO4, as impurity. The impurity is removed by NEET level
• Which of the following is an oxide ore of copper? NEET level
• Match the ore in Column I with its formula in Column II. Column I: (P) Magnetite, (Q) Cerussite, (R) Calamine, (S) Cinnabar. Column II: (1) HgS, (2) PbCO3, (3) ... JEE Main level
• Match the concentration method in Column I with the ore it is typically used for in Column II. Column I: (P) hydraulic washing, (Q) froth flotation, (R) leachin... JEE Main level
• Assertion (A): Sulphide ores are converted into oxides by roasting before they are reduced by carbon. Reason (R): Reduction of a metal sulphide by carbon to giv... JEE Main level
• Assertion (A): In froth flotation the ore particles are carried up in the froth while the gangue settles. Reason (R): The gangue particles are preferentially we... JEE Main level
• In the iron blast furnace, the reaction that supplies heat in the lowest (combustion) zone near the tuyeres is JEE Main level
• Haematite containing silica as the main gangue is smelted with limestone. The flux that actually acts on the gangue, and the slag formed, are respectively JEE Main level
• In the extraction of copper from copper glance, the step in which the sulphide itself reduces the oxide (self-reduction) is JEE Main level
• On an Ellingham diagram of Delta G deg against T, which of the following lines has a negative slope? JEE Main level
• During Bessemerisation of copper matte, silica is added so that the iron(II) oxide present is converted into JEE Main level
• For which of the following ores is calcination, rather than roasting, the proper preliminary treatment? JEE Main level
• Zinc blende is roasted by the reaction 2ZnS + 3O2 -> 2ZnO + 2SO2. Taking Zn = 65, S = 32, O = 16 and molar volume 22.4 L/mol at STP, the mass of O2 needed and t... JEE Main level
• At 1400 K the standard Gibbs energies of formation of oxides, per mole of O2 consumed, are (in kJ): 2C + O2 -> 2CO, -440; 2Fe + O2 -> 2FeO, -380; 4/3 Cr + O2 ->... JEE Advanced level
• A heavy, lead-grey sulphide ore X is concentrated by froth flotation. It is roasted in a limited supply of air to form some oxide together with a pungent gas th... JEE Advanced level
• Select the correct statement(s) about calcination and roasting. JEE Advanced level
• Copper is extracted from 45.9 kg of an ore containing 80.0% CuFeS2 by mass. Smelting follows 2CuFeS2 + O2 -> Cu2S + 2FeS + SO2 and 2FeS + 3O2 -> 2FeO + 2SO2, an... JEE Advanced level
• A green mineral is heated strongly in the absence of air. It loses mass, giving off a gas that turns lime water milky together with water vapour, and leaves a b... JEE Advanced level
• For 2Zn(s) + O2 -> 2ZnO(s): Delta H deg = -700 kJ, Delta S deg = -200 J K^-1. For 2C(s) + O2 -> 2CO(g): Delta H deg = -220 kJ, Delta S deg = +180 J K^-1. Assume... JEE Advanced level
• Select the correct statement(s) about froth flotation of sulphide ores. JEE Advanced level
• Select the correct statement(s) about the iron blast furnace. JEE Advanced level
• Select the correct statement(s) about the Ellingham diagram for oxides. JEE Advanced level
• At 1500 K the standard Gibbs energies per mole of O2 are -887.2 kJ for 4/3 Al + O2 -> 2/3 Al2O3 and -514.6 kJ for 4/3 Cr + O2 -> 2/3 Cr2O3. Find Delta G deg in ... JEE Advanced level