General Principles and Processes of Isolation of Metals JEE Main previous year questions with solutions

5 solved JEE Main questions on General Principles and Processes of Isolation of Metals, free to read — no sign-in needed. The full chapter has 120 questions; sign in to attempt the remaining 115 in the exam simulator.

1. Q1JEE Main 2024 (29 Jan, Shift 1)
   Identify the incorrect pair from the following :
   1. A.Fluorspar- ${BF}_{3}$
   2. B.Cryolite- ${Na}_{3}{AlF}_{6}$
   3. C.Fluoroapatite- $3{Ca}_{3}{\left({PO}_{4}\right)}_{2}\cdot {CaF}_{2}$
   4. D.Carnallite- $KCl\cdot {MgCl}_{2}\cdot 6{H}_{2}O$
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   Answer: (A)

   Fluorine is present mainly as insoluble fluorides (fluorspar ${CaF}_{2}$, cryolite ${Na}_{3}{AlF}_{6}$ and fluoroapatite $3{Ca}_{3}({PO}_{4}{)}_{2}.{CaF}_{2}$ ). Sea water contains chlorides, bromides and iodides of sodium, potassium, magnesium and calcium, but is mainly sodium chloride solution (2.5% by mass). The deposits of dried up seas contain these compounds, e.g., sodium chloride and carnallite, $KCl.{MgCl}_{2}.6{H}_{2}O$.
2. Q2JEE Main 2023 (15 Apr, Shift 1)
   Which one of the following is not an example of calcination?
   1. A.${CaCO}_{3}\rightarrow ^{∆}CaO+{CO}_{2}$
   2. B.${Fe}_{2}{O}_{3}.{xH}_{2}O\rightarrow ^{∆}{Fe}_{2}{O}_{3}+{xH}_{2}O$
   3. C.$2PbS+3{O}_{2}\rightarrow ^{∆}2PbO+2{SO}_{2}$
   4. D.${CaCO}_{3}.{MgCO}_{3}\rightarrow ^{∆}CaO+MgO+2{CO}_{2}$
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   Answer: (C)

   Calcination is a process in which ore is heated in the absence of air or air might be supplied in a limited quantity. Roasting involves the heating of ore lower than its melting point in the presence of air or oxygen. $2PbS+3{O}_{2}\rightarrow ^{∆}2PbO+2{SO}_{2}$ The above reaction is an example of roasting. Rest all the reactions are heated in the absence of oxygen.
3. Q3JEE Main 2023 (13 Apr, Shift 2)
   Given below are two statements related to Ellingham diagram : Statement I : Ellingham diagrams can be constructed for formation of oxides, sulphides and halides of metals. Statement II : It consists of plots of $\Delta H^{\circ}$ vs $T$ for formation of oxides of elements. In the light of the above statements, choose the most appropriate answer from the options given below :
   1. A.Both Statement I and Statement II are correct
   2. B.Both Statement I and Statement II are incorrect
   3. C.Statement I is correct but Statement II is incorrect
   4. D.Statement I is incorrect but Statement II is correct
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   Answer: (C)

   An Ellingham diagram is a graph showing the temperature dependence of the stability of compounds. Ellingham diagrams can be drawn for Sulphides, Oxides and Halides. The Ellingham diagram is a graph that shows how the ${\Delta G}_{f}^{0}$ varies with temperature as a result of the formation of elemental oxides.
4. Q4JEE Main 2023 (13 Apr, Shift 1)
   Which one of the following is most likely a mismatch?
   1. A.Zinc-Liquation
   2. B.Copper-Electrolysis
   3. C.Nickel-Mond process
   4. D.Titanium-van Arkel Method
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   Answer: (A)

   Mond's process involves the combination of carbon monoxide with nickel readily and reversibly and gives nickel tetracarbonyl. This process is used to extract and purify nickel. The Van Arkel technique is used to refine Zirconium or Titanium. Impurities found in Zirconium or Titanium in the form of nitrogen and oxygen are eliminated using this technique. Copper is purified by electrolysis. Electricity is passed through solutions containing copper compounds, such as copper sulphate. The anode (positive electrode ) is made from impure copper and the cathode (negative electrode) is made from pure copper. Mercury and zinc are purified by distillation method. Liquation is a metallurgical method to remove lead containing silver from copper and remove antimony minerals from ore.
5. Q5JEE Main 2023 (11 Apr, Shift 2)
   Given below are two statements: Statement I: In the metallurgy process,sulphide ore is converted to oxide before reduction. Statement II: Oxide ores in general are easier to reduce. In the light of the above statements, choose the most appropriate answer from the options given below:
   1. A.Statement I is correct but Statement II is incorrect
   2. B.Both Statement I and Statement II are incorrect
   3. C.Statement I is incorrect but Statement II is correct
   4. D.Both Statement I and Statement II are correct
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   Answer: (D)

   Both Statement I and Statement II are correct. In many metallurgical processes, sulphide ores are first converted to oxide ores through a process known as roasting or calcination. The conversion of sulphide ore to oxide ore is done to remove the sulphur and simplify the subsequent reduction process. Oxide ores are generally easier to reduce compared to sulphide ores. This is because oxygen is already bonded to the metal in oxide ores, making it easier to remove the oxygen and extract the metal through reduction reactions.