Redox Reactions — JEE Main PYQs & Practice Questions

Redox Reactions is a Chemistry chapter in the JEE Main syllabus. This page brings together 89 previous-year and practice questions on Redox Reactions, organised into 6 topics: Balancing Redox Reactions, Applications of Redox, Oxidation and Reduction, Oxidation Number, Types of Redox Reactions and Redox in Acidic and Basic Medium. Most questions come with a step-by-step solution you can work through free in PrepWiser.

Download Redox Reactions JEE Main PYQs as a free PDF (with answer key)

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Chapter weightage: how many questions each chapter had per shift in the 2024–26 papers.

Balancing Redox Reactions

• 2 IO₃⁻+x I⁻+12 H⁺ → 6 I₂+6 H₂ O What is the value of x ?
• KMnO₄ is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute…
• The number of electrons involved in the reduction of permanganate to manganese dioxide…
• Chlorine undergoes disproportionation in alkaline medium as shown below : aCl_(2( g))+b…
• See the following chemical reaction: Cr₂ O₇²⁻+XH⁺+6 Fₑ²⁺ → YCr³⁺+6 Fₑ³⁺+Z H₂ O The sum…
• 15 mL of aqueous solution of Fe²⁺ in acidic medium completely reacted with 20 mL of 0.03…

Applications of Redox

• KMnO₄ oxidises I⁻ in acidic and neutral/faintly alkaline solutions, respectively, to :
• 20 mL of 0.02 M K₂ Cr₂ O₇ solution is used for the titration of 10 mL of Fe²⁺ solution…
• 20 mL of 0.02 M hypo solution is used for the titration of 10 mL of copper sulphate…
• Given below are two statements: Statement I : In redox titration, the indicators used…
• H₂ O₂ acts as a reducing agent in :
• 10.0 mL of 0.05 M KMnO₄ solution was consumed in a titration with 10.0 mL of given…
• 0.01 M KMnO₄ solution was added to 20.0 mL of 0.05 M Mohr's salt solution through a…
• 200 cc of x× 10⁻³M potassium dichromate is required to oxidise 750 cc of 0.6 M Mohr's…
• In order to oxidise a mixture of 1 mole each of FeC₂O₄,Fe₂(C₂O₄)₃,FeSO₄ and Fe₂(SO₄)₃ in…
• When 10 mL of an aqueous solution of KMnO₄ was titrated in acidic medium, equal volume…
• The products obtained from a reaction of hydrogen peroxide and acidified potassium…
• 500 mL of 0.2MMnO₄⁻solution in basic medium when mixed with 500 mL of 1.5 M KI solution…
• 500 mL of 1.2 M KI solution is mixed with 500 mL of 0.2MKMnO₄ solution in basic medium…
• When Cu²⁺ ion is treated with KI, a white precipitate, X appears in solution. The…
• In basic medium, H₂O₂ exhibits which of the following reactions? (A) Mn²⁺ → Mn⁴⁺ (B) I²…
• Which of the following options are correct for the reaction 2[Au(CN)₂]⁻(aq)+Zn(s) → 2…
• Only 2 mL of KMnO₄ solution of unknown molarity is required to reach the end point of a…
• A 20.0 mL solution containing 0.2 g impure H₂O₂ reacts completely with 0.316 g of KMnO₄…
• A 2.0 g sample containing MnO₂ is treated with HCl liberating Cl₂. The Cl₂ gas is passed…
• When 10 mL of an aqueous solution of Fe²⁺ ions was titrated in the presence of dil H₂SO₄…

Oxidation and Reduction

• X and Y are the number of electrons involved, respectively during the oxidation of I⁻to…
• The redox reaction among the following is :
• Which of the following cannot function as an oxidising agent?
• The compound that cannot act both as oxidising and reducing agent is :
• Strong reducing and oxidizing agents among the following, respectively, are :
• (A) HOCI + H₂O₂ → H₃O⁺ + Cl⁻ + O₂ (B) I₂ + H₂O₂ + 2OH⁻ → 2I⁻ + 2H₂O + O₂ Choose the…

Oxidation Number

• Given below are two statements : Statement (I) : The oxidation state of an element in a…
• The sum of oxidation states of two silver ions in [Ag(NH₃)₂] [Ag(CN)₂] complex is…
• The total change in the oxidation state of manganese involved in the reaction of KMnO₄…
• In Chromyl chloride, the oxidation state of chromium is (+) _______________.
• Sum of oxidation states of bromine in bromic acid and perbromic acid is ___________.
• Dichromate ion is treated with base, the oxidation number of Cr in the product formed is…
• Manganese (VI) has ability to disproportionate in acidic solution. The difference in…
• The sum of oxidation state of the metals in Fe(CO)₅, VO²⁺ and WO₃ is ___________.
• Identify the process in which change in the oxidation state is five :
• The oxidation state of chromium in the final product formed in the reaction between KI…
• The dark purple colour of KMnO₄ disappears in the titration with oxalic acid in acidic…
• In the reaction of potassium dichromate, potassium chloride and sulfuric acid (conc.)…
• Oxidation number of potassium in K₂O. K₂O₂ and KO₂ respectively is :
• Fex₂ and Fey₃ are known when x and y are :
• A sample of a metal oxide has formula M_(0.83) O_(1.00). The metal M can exist in two…
• On heating, lead (II) nitrate gives a brown gas (A). The gas (A) on cooling changes to a…
• The oxidation state of phosphorus in hypophosphoric acid is + _____________.
• The oxidation state of iodine in HIO₄ (periodic acid) is:
• The oxidation state of phosphorus in H₃PO₄ is:
• On reaction with stronger oxidizing agent like KIO₄, hydrogen peroxide oxidizes with the…

Types of Redox Reactions

• Given below are two statements: Statement (I): Oxidising power of halogens decreases in…
• Match List I with List II. LIST I Reaction | LIST II Type of redox reaction; A. | N_(2(…
• The species which does not undergo disproportionation reaction is :
• Total number of species from the following which can undergo disproportionation reaction…
• Given below are two statements: Statement I : S₈ solid undergoes disproportionation…
• Which of the following reactions are disproportionation reactions? (A) Cu⁺ → Cu²⁺+Cu (B)…
• Match the List - I with List - II List - I (Redox Reaction) | List - II (Type of Redox…
• The species given below that does NOT show disproportionation reaction is :
• Which one of the following is an example of disproportionation reaction ?
• Which of the given reactions is not an example of disproportionation reaction?
• Thiosulphate reacts differently with iodine and bromine in the reactions given below: 2…
• One mole of Cl₂( g) was passed into 2 L of cold 2 M KOH solution. After the reaction…

Redox in Acidic and Basic Medium

• In alkaline medium, the reduction of permanganate anion involves a gain of __________…
• In mildly alkaline medium, thiosulphate ion is oxidized by MnO₄ - to "A". The oxidation…
• Hydrogen peroxide reacts with iodine in basic medium to give :
• In basic medium CrO₄²⁻ oxidises S₂O₃²⁻ to form SO₄²⁻ and itself changes into Cr(OH)₄ -…
• During the reaction of permanganate with thiosulphate, the change in oxidation of…
• The reaction of sulphur in alkaline medium is given below: S₈₍ₛ₎ + a OH⁻_((aq)) → b…
• In alkaline medium, MnO₄⁻ oxidises I⁻ to
• 2 MnO₄⁻+bI⁻+cH₂ O → x I₂+y MnO₂+z O̅ H If the above equation is balanced with integer…
• Consider the following equations : 2Fe²⁺ + H₂O₂ → xA + yB (in basic medium) 2MnO₄⁻ + 6H⁺…
• In acidic medium, K₂ Cr₂ O₇ shows oxidising action as represented in the half reaction…
• In neutral or alkaline solution, MnO₄⁻ oxidises thiosulphate to :
• Number of moles of H⁺ ions required by 1 mole of MnO₄⁻ to oxidise oxalate ion to CO₂ is…
• The volume, in mL, of 0.02 M K₂Cr₂O₇ solution required to react with 0.288 g of ferrous…
• In the given chemical reaction, colors of the Fe²⁺ and Fe³⁺ ions, are respectively…
• The reaction of H₂ O₂ with potassium permanganate in acidic medium leads to the…
• 2MnO₄ - + bC₂O₄²⁻ + cH + → xMn²⁺ + yCO₂ + zH₂O If the above equation is balanced with…

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• Gaseous State
• Chemical Thermodynamics
• Chemical Equilibrium
• Ionic Equilibrium
• Solutions & Colligative Properties
• Electrochemistry
• Chemical Kinetics
• Solid State
• Surface Chemistry
• Nuclear & Radiochemistry
• Periodic Table & Periodicity
• Chemical Bonding & Molecular Structure
• Hydrogen & s-Block Elements
• p-Block Elements — Part I (Group 13 & 14)
• Environmental Chemistry
• p-Block Elements — Part II (Group 15-18)
• d & f Block Elements
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• Metallurgy
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• Hydrocarbons — Alkanes
• Hydrocarbons — Alkenes & Alkynes
• Hydrocarbons — Aromatic (Arenes)
• Halogen Derivatives — Haloalkanes & Haloarenes
• Alcohols, Phenols & Ethers
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Frequently asked questions

How many Redox Reactions questions are there for JEE Main?

PrepWiser has 89 Redox Reactions questions for JEE Main, grouped into 6 topics such as Balancing Redox Reactions, Applications of Redox and Oxidation and Reduction.

Are these Redox Reactions questions from previous-year JEE Main papers?

Yes — most are genuine previous-year questions from past JEE Main papers, and the rest are practice questions written to match the JEE Main pattern and difficulty.

Where can I see the answers and solutions to these Redox Reactions questions?

Open any Redox Reactions question in PrepWiser (it is free) to attempt it; most come with a step-by-step solution.