JEE Chemistry General Principles and Processes Of Isolation Of Elements MCQs Set 03

Multiple Choice Questions (MCQs) for JEE Chemistry: General Principles and Processes Of Isolation Of Elements

Explore reliable objective questions for General Principles and Processes Of Isolation Of Elements tailored for JEE learners. Utilizing these Chemistry multiple-choice formats ensures thorough preparation and strengthens problem-solving speed for upcoming school assessments.

Practice General Principles and Processes Of Isolation Of Elements MCQs for JEE Chemistry

View or download the dedicated General Principles and Processes Of Isolation Of Elements MCQ resource below. Practicing these 50 objective questions regularly builds familiarity with standard exam patterns and helps secure higher marks in final Chemistry evaluations.

Multiple Choice Questions

Question 1: Which of the following metals is not found in the free (native) state?
(a) Zn
(b) Au
(c) Ag
(d) Hg
Show Answer & Explanation

Answer: (a) Zn

Explanation:
1. Zn is reactive and occurs as ZnS (zinc blende), ZnCO3 (calamine) and ZnO (zincite).
2. Au and Ag occur native, and Hg occurs native in traces.

Teacher's Note:
1. Native metals are the least reactive ones: Au, Ag, Pt, Cu (rare).
2. Reactive metals occur as compounds.

Question 2: All ores are minerals but all minerals are not ores because
(a) the metal cannot be extracted economically from all minerals
(b) minerals are complex compounds
(c) minerals are obtained from mines
(d) all of these are correct
Show Answer & Explanation

Answer: (a) the metal cannot be extracted economically from all minerals

Explanation:
1. An ore is a mineral from which the metal can be extracted profitably.
2. Many minerals have too little metal or are too costly to process.

Teacher's Note:
1. Ore = economically viable mineral.
2. Clay is a mineral of Al but not an ore of Al.

Question 3: Which one of the following does not occur as a sulphide ore?
(a) Zn
(b) Cr
(c) Ag
(d) Fe
Show Answer & Explanation

Answer: (b) Cr

Explanation:
1. Zn (blende), Ag (argentite) and Fe (pyrites) all occur as sulphides.
2. Chromium occurs as chromite FeCr2O4, an oxide ore.

Teacher's Note:
1. Chromite is the main ore of chromium.
2. Sulphide ores are concentrated by froth floatation.

Question 4: Which metal is extracted by electrolytic reduction (electrometallurgy)?
(a) Cu
(b) Ca
(c) Fe
(d) Ag
Show Answer & Explanation

Answer: (b) Ca

Explanation:
1. Ca is highly electropositive and cannot be reduced by carbon; it is obtained by electrolysis of fused CaCl2.

Teacher's Note:
1. Highly electropositive metals (Na, K, Ca, Mg, Al) are extracted by fused salt electrolysis.

Question 5: Which metal is extracted by carbon reduction?
(a) Cu
(b) Ca
(c) Hg
(d) Zn
Show Answer & Explanation

Answer: (d) Zn

Explanation:
1. ZnO is reduced by coke at about 1673 K: ZnO + C → Zn + CO.
2. Ca needs electrolysis, Hg is obtained by roasting, and Cu is obtained by self-reduction.

Teacher's Note:
1. Check the Ellingham diagram for the oxide: carbon reduces ZnO above about 1200 K.
2. Zn vapour is collected and condensed.

Question 6: Lapis lazuli, a blue precious stone, is a mineral of the class
(a) sodium alumino-silicate
(b) zinc cobaltate
(c) basic copper carbonate
(d) Prussian blue
Show Answer & Explanation

Answer: (a) sodium alumino-silicate

Explanation:
1. Lapis lazuli is a sodium alumino-silicate containing sulphur, Na8[Al6Si6O24]Sn.

Teacher's Note:
1. Do not confuse it with azurite (blue basic copper carbonate).

Question 7: The lustre of a metal is due to
(a) its high density
(b) polished surface
(c) its chemical inertness
(d) presence of free electrons
Show Answer & Explanation

Answer: (d) presence of free electrons

Explanation:
1. Free electrons absorb and re-emit light, giving the metallic lustre.

Teacher's Note:
1. Free electrons also explain conductivity and malleability.

Question 8: Which process is used in the extraction of magnesium?
(a) Fused salt electrolysis
(b) Self reduction
(c) Aqueous solution electrolysis
(d) Thermite reduction
Show Answer & Explanation

Answer: (a) Fused salt electrolysis

Explanation:
1. Mg is highly electropositive.
2. It is obtained by electrolysis of fused anhydrous MgCl2 (or carnallite) mixed with NaCl and CaCl2.

Teacher's Note:
1. Aqueous electrolysis would liberate H2 instead of Mg.

Question 9: Which metal is commercially extracted by a hydrometallurgical process involving complexation?
(a) Mg
(b) Au
(c) Cu
(d) Zn
Show Answer & Explanation

Answer: (b) Au

Explanation:
1. Gold is leached with dilute NaCN in air to form [Au(CN)2]−, and then displaced with zinc dust.

Teacher's Note:
1. Cyanide leaching is used for Au and Ag.

Question 10: Which metal is obtained by self-reduction?
(a) Copper
(b) Iron
(c) Silver
(d) Magnesium
Show Answer & Explanation

Answer: (a) Copper

Explanation:
1. In the extraction of copper, Cu2S reacts with Cu2O in the absence of air: 2Cu2O + Cu2S → 6Cu + SO2.

Teacher's Note:
1. Self-reduction is used for Cu, Pb and Hg.

Question 11: The cyanide process is used for the extraction of
(a) Au
(b) Ag
(c) Al
(d) both Au and Ag
Show Answer & Explanation

Answer: (d) both Au and Ag

Explanation:
1. Native Au and Ag, and Ag2S, dissolve in NaCN in the presence of air to give cyano complexes.

Teacher's Note:
1. The complexes are reduced by zinc dust.

Question 12: Froth floatation for the concentration of ores is an illustration of the physical phenomenon of
(a) adsorption
(b) absorption
(c) coagulation
(d) sedimentation
Show Answer & Explanation

Answer: (a) adsorption

Explanation:
1. Sulphide ore particles are wetted by oil and adsorbed on air bubbles that rise to the surface.

Teacher's Note:
1. Preferential wetting: ore by oil, gangue by water.

Question 13: The method of concentration that uses the difference in density between ore and impurities is called
(a) levigation
(b) leaching
(c) magnetic separation
(d) liquation
Show Answer & Explanation

Answer: (a) levigation

Explanation:
1. Levigation (hydraulic washing or gravity separation) washes away lighter gangue by flowing water.

Teacher's Note:
1. Used for heavy oxide ores such as haematite and cassiterite.

Question 14: During concentration of tin stone, the separation of wolframite from SnO2 by electromagnetic separation is possible because
(a) SnO2 is paramagnetic
(b) SnO2 is diamagnetic
(c) FeWO4 and MnWO4 are paramagnetic
(d) both (b) and (c)
Show Answer & Explanation

Answer: (d) both (b) and (c)

Explanation:
1. Wolframite (FeWO4, MnWO4) is magnetic and SnO2 is non-magnetic.
2. A magnetic roller therefore separates them.

Teacher's Note:
1. The magnetic impurity is pulled off first.

Question 15: Leaching of Ag2S with NaCN solution is carried out in the presence of air because
(a) [Ag(CN)2]− is formed in a reversible reaction
(b) the Na2S formed is oxidised to Na2SO4 and sulphur
(c) both (a) and (b)
(d) none of the above
Show Answer & Explanation

Answer: (c) both (a) and (b)

Explanation:
1. Ag2S + 4NaCN ⇌ 2Na[Ag(CN)2] + Na2S is reversible.
2. Air oxidises Na2S to Na2SO4 and S, driving the reaction forward.

Teacher's Note:
1. Removal of a product shifts the equilibrium forward.

Question 16: In froth floatation, pine oil functions as
(a) activator
(b) frother
(c) collector
(d) agitator
Show Answer & Explanation

Answer: (b) frother

Explanation:
1. Pine oil stabilises the froth.
2. Collectors such as sodium ethyl xanthate make the sulphide particles water repellent.

Teacher's Note:
1. Frother: pine oil, cresols. Collector: xanthates. Depressant: NaCN.

Question 17: Which of the following can act as a collector in froth floatation?
(a) sodium ethyl xanthate
(b) sodium xenate
(c) sodium pyrophosphate
(d) sodium chloride
Show Answer & Explanation

Answer: (a) sodium ethyl xanthate

Explanation:
1. Sodium ethyl xanthate attaches to the sulphide surface and makes it water repellent so that it enters the froth.

Teacher's Note:
1. Collectors bind to the ore; frothers stabilise bubbles.

Question 18: In froth floatation of galena containing ZnS as impurity, NaCN is added as a depressant because
(a) Pb(CN)2 is precipitated while ZnS is unaffected
(b) ZnS forms a soluble complex Na2[Zn(CN)4] while PbS combines with the frother
(c) PbS forms a soluble complex while ZnS combines with the frother
(d) NaCN regenerates ZnS from its complex
Show Answer & Explanation

Answer: (b) ZnS forms a soluble complex Na2[Zn(CN)4] while PbS combines with the frother

Explanation:
1. NaCN forms a soluble complex with ZnS, stopping it from floating.
2. PbS does not form this complex and floats with the froth.

Teacher's Note:
1. Depressants separate two sulphides by selective wetting.
2. Pb and Zn sulphides are separated this way.

Question 19: Which of the following sulphide ores is concentrated by leaching?
(a) Argentite
(b) Galena
(c) Copper pyrite
(d) Sphalerite
Show Answer & Explanation

Answer: (a) Argentite

Explanation:
1. Argentite (Ag2S) is leached with dilute NaCN solution.
2. Galena, copper pyrite and sphalerite are concentrated by froth floatation.

Teacher's Note:
1. Leaching = chemical concentration.

Question 20: Magnetic separation is used for the concentration of
(a) horn silver
(b) gypsum
(c) chromite
(d) magnesite
Show Answer & Explanation

Answer: (c) chromite

Explanation:
1. Chromite (FeCr2O4) is magnetic.
2. The other ores are non-magnetic.

Teacher's Note:
1. Other magnetic ores: wolframite, haematite (weak), pyrolusite.

Question 21: Bauxite is concentrated by
(a) froth floatation
(b) magnetic separation
(c) chemical leaching
(d) gravity separation
Show Answer & Explanation

Answer: (c) chemical leaching

Explanation:
1. Bauxite is leached with hot concentrated NaOH (Baeyer's process) to dissolve Al2O3 as NaAlO2.

Teacher's Note:
1. Impurities Fe2O3 and TiO2 remain as solids.

Question 22: Zinc blende is concentrated by
(a) froth floatation
(b) magnetic separation
(c) leaching
(d) roasting
Show Answer & Explanation

Answer: (a) froth floatation

Explanation:
1. Zinc blende (ZnS) is a sulphide ore and is concentrated by froth floatation.

Teacher's Note:
1. Roasting is not a concentration step; it is a chemical conversion.

Question 23: Gravity separation is mainly used for the concentration of
(a) calamine
(b) haematite
(c) chalcopyrite
(d) bauxite
Show Answer & Explanation

Answer: (b) haematite

Explanation:
1. Haematite is a heavy oxide ore separated from light silica gangue by washing with water.

Teacher's Note:
1. Heavy oxides: haematite, cassiterite.

Question 24: Which of the following is not a method of concentration of ores?
(a) Gravity separation
(b) Froth floatation
(c) Electromagnetic separation
(d) Bessemerisation
Show Answer & Explanation

Answer: (d) Bessemerisation

Explanation:
1. Bessemerisation is a converter process used to convert Cu2S into blister copper (and steel making), not a concentration step.

Teacher's Note:
1. Concentration means removing gangue physically or chemically.

Question 25: Which of the following is not an ore?
(a) Azurite
(b) Siderite
(c) Clay
(d) Cerussite
Show Answer & Explanation

Answer: (c) Clay

Explanation:
1. Clay (Al2O3·2SiO2·2H2O) contains aluminium but extraction is uneconomical; it is a mineral, not an ore.

Teacher's Note:
1. Azurite (Cu), siderite (Fe) and cerussite (Pb) are ores.

Free study material for Chemistry

Download Chapter MCQs: JEE Chemistry General Principles and Processes Of Isolation Of Elements

About General Principles and Processes Of Isolation Of Elements MCQs for JEE Chemistry

Review structured objective questions for JEE Chemistry General Principles and Processes Of Isolation Of Elements. Built according to official JEE guidelines, these MCQ sets support daily revision and core concept reinforcement.

How to Verify Your MCQ Answers

Cross-reference your completed choices with comprehensive NCERT solutions for JEE Chemistry to ensure absolute clarity across all sub-topics in this chapter.

Enhance Speed with Online MCQ Tests

Follow up your worksheet practice by attempting the interactive online Chemistry MCQ test for this chapter to evaluate your execution speed. All platform resources are free to access.

FAQs

Where can I access latest JEE Chemistry General Principles and Processes Of Isolation Of Elements MCQs Set 03?

You can get most exhaustive JEE Chemistry General Principles and Processes Of Isolation Of Elements MCQs Set 03 for free on StudiesToday.com. These MCQs for JEE Chemistry are updated for the 2026-27 academic session as per JEE examination standards.

Are Assertion-Reasoning and Case-Study MCQs included in the Chemistry JEE material?

Yes, our JEE Chemistry General Principles and Processes Of Isolation Of Elements MCQs Set 03 include the latest type of questions, such as Assertion-Reasoning and Case-based MCQs. 50% of the JEE paper is now competency-based.

How do practicing Chemistry MCQs help in scoring full marks in JEE exams?

By solving our JEE Chemistry General Principles and Processes Of Isolation Of Elements MCQs Set 03, JEE students can improve their accuracy and speed which is important as objective questions provide a chance to secure 100% marks in the Chemistry.

Do you provide answers and explanations for JEE Chemistry General Principles and Processes Of Isolation Of Elements MCQs Set 03?

Yes, Chemistry MCQs for JEE have answer key and brief explanations to help students understand logic behind the correct option as its important for 2026 competency-focused JEE exams.

Can I practice these Chemistry JEE MCQs online?

Yes, you can also access online interactive tests for JEE Chemistry General Principles and Processes Of Isolation Of Elements MCQs Set 03 on StudiesToday.com as they provide instant answers and score to help you track your progress in Chemistry.