JEE PYQ Redox Reactions - Chapter-wise Questions with Solutions

About Redox Reactions PYQs

Redox Reactions has 295 previous year questions in the Quantrex Academy JEE Main & Advanced Chemistry bank. The 220 questions in this list come from JEE Main (107), NTA Abhyas JEE Main (54), JEE Advanced (28) and 2 other sources, spanning 2002 to 2026. Each question opens on its own page with the options, the correct answer and the worked solution where available.

JEE Redox Reactions PYQs with Solutions

About Redox Reactions PYQs

Questions by year (this list)

Redox Reactions questions with solutions

500 mL of 0.2 M MnO _4^- solution in basic medium when mixed with 500 mL of 1.5 M KI solution, oxidises iodide ions to liberate molecular iodine. This liberated iodine is then

Given below are two statements: Statement I: Sodium dichromate and potassium dichromate are classified as primary standards in titrimetric analysis. Statement II: Phenolphthalein

In order to oxidise a mixture of 1 mole each of FeC_2O_4 , Fe_2(C_2O_4)_3 , FeSO_4 and Fe_2(SO_4)_3 in acidic medium, the number of moles of KMnO_4 required is

500 mL of 1.2 M KI solution is mixed with 500 mL of 0.2 M KMnO_ 4 solution in basic medium. The liberated iodine was titrated with standard 0.1 M Na_ 2 ~S_ 2 O_ 3 solution in the

One mole of Cl_ 2 (~g) was passed into 2 L of cold 2 M KOH solution. After the reaction, the concentrations of Cl^ - , ClO^ - and OH^ - are respectively (assume volume remains

X and Y are the number of electrons involved, respectively during the oxidation of I^ - to I_ 2 and S^ 2- to S by acidified K_ 2 Cr_ 2 O_ 7 . The value of X+Y is \_\_\_\_ .

200 cc of x × 10^ -3 M potassium dichromate is required to oxidise 750 cc of 0.6 M Mohr's salt solution in acidic medium. Here x= \_\_\_\_ .

Identify the correct statements : A. Hydrated salts can be used as primary standard. B. Primary standard should not undergo any reaction with air. C. Reactions of primary standard

One of the products formed from the reaction of permanganate ion with iodide ion in neutral aqueous medium is

Compounds that should not be used as primary standards in titrimetric analysis are : A. Na_2 Cr_2 O_7 B. Oxalic acid C. NaOH D. FeSO_4 · 6 H_2 O E. Sodium tetraborate Choose the

0.1 M solution of KI reacts with excess of H_2 SO_4 and KIO_3 solutions. According to equation 5 I^ - +IO_3^ - +6 H^ + arrow 3 I_2+3 H_2 O Identify the correct statements : (A)

Match the LIST-I with LIST-II Choose the correct answer from the options given below:

Given below are two statements: Statement I: In the oxalic acid vs KMnO_4 (in the presence of dil H_2 SO_4 ) titration the solution needs to be heated initially to 60^ ∘ C , but

The species which does not undergo disproportionation reaction is :

Some CO_2 gas was kept in a sealed container at a pressure of 1 atm and at 273 K . This entire amount of CO_2 gas was later passed through an aqueous solution of Ca(OH)_2 . The

In a metal deficient oxide sample, M_ x Y_2 O_4 ( M and Y are metals), M is present in both +2 and +3 oxidation states and Y is in +3 oxidation state. If the fraction of M^ 2+

At room temperature, disproportionation of an aqueous solution of in situ generated nitrous acid (HNO_2) gives the species

Identify the incorrect statements regarding primary standard of titrimetric analysis. (A) It should be purely available in dry form. (B) It should not undergo chemical change in

Among the following halogens \(F_2, Cl_2, Br_2\) and \(I_2\) Which can undergo disproportionation reactions?

Thiosulphate reacts differently with iodine and bromine in the reactions given below: \( aligned & 2 ~S_2 O_3^ 2- +I_2 arrow S_4 O_6^ 2- +2 I^ - & S_2 O_3^ 2- +5 Br_2+5 H_2 O

Match List - I with List - II. \( List - I List - II Reaction Type of redox reaction (A) N_ 2( g) +O_ 2( g) → 2 NO_ (g) (I) Decomposition (B) 2 Pb (NO_3)_ 2( s) → 2 PbO_ (s) +4

Only \(2 ~mL\) of \(KMnO_4\) solution of unknown molarity is required to reach the end point of a titration of \(20 ~mL\) of oxalic acid \((2 M)\) in acidic medium. The molarity

Which of the following reactions are disproportionation reactions? (1) Cu ^ + → Cu ^ 2 + + Cu (2)3 MnO _ 4 ^ 2 - + 4 H ^ + → 2 MnO _ 4 ^ - + MnO _ 2 + 2 H _ 2 O (3)2 KMnO _ 4 → K

In acidic medium, K _ 2 Cr _ 2 O _ 7 shows oxidising action as represented in the half reaction Cr _ 2 O _ 7 ^ 2 - + XH ^ + + Ye ^ - → 2A + ZH _ 2 O X, Y, Z and A are respectively

Given below are two statements : Statement (I) : Potassium hydrogen phthalate is a primary standard for standardisation of sodium hydroxide solution. Statement (II) : In this

Given below are two statements : Statement I: S _ 8 solid undergoes disproportionation reaction under alkaline conditions to form S ^ 2 - and S _ 2 O _ 3 ^ 2 - Statement II: ClO _

Total number of species from the following which can undergo disproportionation reaction ___________. H _ 2 O _ 2 , ClO _ 3 ^ - , P _ 4 , Cl _ 2 , Ag, Cu ^ + 1 , F _ 2 , NO _ 2

2 MnO _ 4 ^ - + bI ^ - + cH _ 2 O → xI _ 2 + yMnO _ 2 + zOH ^ - If the above equation is balanced with integer coefficients, the value of z is ________.

If 50mL of 0 . 5M oxalic acid is required to neutralise 25mL of NaOH solution, the amount of NaOH in 50mL of given NaOH solution is_______g.

Chlorine undergoes disproportionation in alkaline medium as shown below : aCl _ 2 ( g ) + bOH ^ - ( aq ) → cClO ^ - ( aq ) + dCl ^ - ( aq ) + eH _ 2 O ( l ) The values of a, b, c

KMnO _ 4 decomposes on heating at 513K to form O _ 2 along with

Which of the following cannot function as an oxidising agent?

H _ 2 S ( 5 moles) reacts completely with acidified aqueous potassium permanganate solution. In this reaction, the number of moles of water produced is x , and the number of moles

Consider the following molecules : Br _ 3 O _ 8 , F _ 2 O, H _ 2 S _ 4 O _ 6 , H _ 2 S _ 5 O _ 6 , and C _ 3 O _ 2 . Count the number of atoms existing in their zero oxidation

The total change in the oxidation state of manganese involved in the reaction of KMnO _ 4 and potassium iodide in the acidic medium is ________.

See the following chemical reaction: Cr _ 2 O _ 7 ^ 2 - + XH ^ + + 6 Fe ^ 2 + → YCr ^ 3 + + 6 Fe ^ 3 + + ZH _ 2 O The sum of X, Y and Z is

KMnO _ 4 is titrated with ferrous ammonium sulphate hexahydrate in presence of dilute H _ 2 SO _ 4 . Number of water molecules produced for 2 molecules of KMnO _ 4 is _______

20mL of calcium hydroxide was consumed when it was reacted with 10mL of unknown solution of H _ 2 SO _ 4 . Also 20mL standard solution of 0 . 5MHCl containing 2 drops of

In alkaline medium, the reduction of permanganate anion involves a gain of ____________ electrons.

Given below are two statements: Statement I: In redox titration, the indicators used are sensitive to change in pH of the solution. Statement II: In acid-base titration, the

2 IO _ 3 ^ - + xI ^ - + 12 H ^ + → 6 I _ 2 + 6 H _ 2 What is the value of x ?

During the reaction of permanganate with thiosulphate, the change in oxidation of manganese occurs by value of 3 . Identify which of the below medium will favour the reaction.

The volume of 0 . 02M aqueous HBr required to neutralize 10 . 0mL of 0 . 01M aqueous Ba ( OH ) _ 2 is (Assume complete neutralization)

Which of the following options are correct for the reaction? 2 [Au ( CN ) _ 2 ] ^ - ( aq ) + Zn ( s ) → 2Au ( s ) + [Zn ( CN ) _ 4 ] ^ 2 - ( aq ) A. Redox reaction B. Displacement

Strong reducing and oxidizing agents among the following , respectively, are

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A) : An aqueous solution of KOH when for volumetric analysis

The density of a monobasic strong acid (Molar mass 24 . 2gmol ) is 1 . 21kgL . The volume of its solution required for the complete neutralization of 25mL of 0 . 24MNaOH is 10 ^

Choose the correct representation of conductometric titration of benzoic acid vs sodium hydroxide.

A compound &#39; X &#39; is a weak acid and it exhibits colour change at pH close to the equivalence point during neutralization of NaOH with CH _ 3 COOH . Compound &#39; X &#39

Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R Assertion A : Permanganate titration are not performed in presence of

The normality of H _ 2 SO _ 4 in the solution obtained on mixing 100mL of 0 . 1M H _ 2 SO _ 4 with 50mL of 0 . 1MNaOH is____ × 10 ^ - 1 N .

20mL of 0 . 02 MK _ 2 Cr _ 2 O _ 7 solution is used for the titration of 10mL of Fe ^ 2 + solution in the acidic medium. The molarity of Fe ^ 2 + solution is____ × 10 ^ - 2 M

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R . Assertion A :Phenolphthalein is a pH dependent indicator, remains colourless

20mL of 0 . 02M hypo solution is used for the titration of 10mL of copper sulphate solution, in the presence of excess of KI using starch as an indicator. The molarity of Cu ^ 2 +

Which of the given reactions is not an example of disproportionation reaction?

For the reaction given below: CoCl _ 3 . xNH _ 3 + AgNO _ 3 (aq) → If two equivalents of AgCl precipitate out, then the value of x will be _______

0 . 01 MKMnO _ 4 solution was added to 20 . 0mL of 0 . 05MMohr &#39;s salt solution through a burette. The initial reading of 50mL burette is zero. The volume of KMnO _ 4 solution

A 2 . 0g sample containing MnO _ 2 is treated with HCl liberating Cl _ 2 . The Cl _ 2 gas is passed into a solution of KI and 60 . 0mL of 0 . 1 MNaS _ 2 O _ 3 is required to

Which one of the following is an example of disproportionation reaction?

The neutralization occurs when 10mL of 0 . 1M acid &#39; A &#39; is allowed to react with 30mL of 0 . 05M base M (OH) _ 2 . The basicity of the acid &#39; A &#39; is [ M is a

Manganese (VI) has ability to disproportionate in acidic solution. The difference in oxidation states of two ions it forms in acidic solution is

A 0 . 166g sample of an organic compound was digested with conc. H _ 2 SO _ 4 and then distilled with NaOH . The ammonia gas evolved was passed through 50 . 0mL of 0 . 5N H _ 2 SO

A sample (5.6 ~g) containing iron is completely dissolved in cold dilute HCl to prepare a 250 ~mL of solution. Titration of 25.0 ~mL of this solution requires 12.5 ~mL of 0.03 M

A sample (5.6 ~g) containing iron is completely dissolved in cold dilute HCl to prepare a 250 ~mL of solution. Titration of 25.0 ~mL of this solution requires 12.5 ~mL of 0.03 M

In which one of the following sets all species show disproportionation reaction?

In polythionic acid, H _ 2 S _ x O _ 6 ( x = 3 to 5 ) the oxidation state(s) of sulphur is/are:

10 . 0mL of 0 . 05M KMnO _ 4 solution was consumed in a titration with 10 . 0mL of given oxalic acid dihydrate solution. The strength of given oxalic acid solution is ........ ×

The oxidation states of ' P ' in H _ 4 P _ 2 O _ 7 , H _ 4 P _ 2 O _ 5 and H _ 4 P _ 2 O _ 6 , respectively, are :

Identify the process in which change in the oxidation state is five :

When 10mL of an aqueous solution of Fe ^ 2 + ions was titrated in the presence of dil H _ 2 SO _ 4 using diphenylamine indicator, 15mL of 0 . 02M solution of K _ 2 Cr _ 2 O _ 7

Cu ^ 2 + salt reacts with potassium iodide to give

4g equimolar mixture of NaOH and Na _ 2 CO _ 3 contains xg of NaOH and yg of Na _ 2 CO _ 3 . The value of x is g . (Nearest integer)

The species given below that does NOT show disproportionation reaction is:

250mL of 0 . 5MNaOH was added to 500mL of 1M HCl . The number of unreacted HCl molecules in the solution after the complete reaction is p × 10 ^ 21 . Find out p (Nearest integer)

The oxidation states of nitrogen in NO, NO _ 2 , N _ 2 O and NO _ 3 ^ - are in the order of :

15mL of aqueous solution of Fe ^ 2 + in acidic medium completely reacted with 20mL of 0 . 03M aqueous Cr _ 2 O _ 7 ^ 2 - . The molarity of the Fe ^ 2 + solution is _______ × 10 ^

A compound ' X ' is a weak acid and it exhibits colour change at pH close to the equivalence point during neutralization of NaOH with CH _ 3 COOH . Compound ' X &#39

0 . 01 MKMnO _ 4 solution was added to 20 . 0mL of 0 . 05MMohr 's salt solution through a burette. The initial reading of 50mL burette is zero. The volume of KMnO _ 4 solution

The neutralization occurs when 10mL of 0 . 1M acid ' A ' is allowed to react with 30mL of 0 . 05M base M (OH) _ 2 . The basicity of the acid ' A ' is [ M is a

The reaction of sulphur in alkaline medium is given below: S _ 8(s) + a OH _ (aq) ^ - → b S _ (aq) ^ 2 - + c S _ 2 O _ 3(aq) ^ 2 - + d H _ 2 O _ (l) The values of ' a &#39