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Chemistry · d and f Block Elements

JEE Main 2025 — 28 January, Morning Shift — Question 44

Which of the following oxidation reactions are carried out by both K2Cr2O7\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7} and KMnO4\mathrm{KMnO}_{4} in acidic medium ?

A. I−→I2\mathrm{I}^{-} \rightarrow \mathrm{I}_{2}

B. S2−→SS^{2-} \rightarrow S

C. Fe2+→Fe3+\mathrm{Fe}^{2+} \rightarrow \mathrm{Fe}^{3+}

D. I−→IO3−\mathrm{I}^{-} \rightarrow \mathrm{IO}_{3}^{-}

E. S2O32−→SO42−\mathrm{S}_{2} \mathrm{O}_{3}{ }^{2-} \rightarrow \mathrm{SO}_{4}{ }^{2-}

Choose the correct answer from the options given below :

  1. Option A:

    B, C and D only

  2. Option B:

    A, D and E only

  3. Option C:

    A, B and C only

    Correct
  4. Option D:

    C, D and E only

Answer: C

Step-by-step solution

I−→H+I2\mathrm{I}^{-} \xrightarrow{\mathrm{H}^{+}} \mathrm{I}_{2}

I−→OH−IO3−\mathrm{I}^{-} \xrightarrow{\mathrm{OH}^{-}} \mathrm{IO}_{3}^{-}

S−2→H+S\mathrm{S}^{-2} \xrightarrow{\mathrm{H}^{+}} \mathrm{S}

S2O32−→OH−SO42−\mathrm{S}_{2} \mathrm{O}_{3}^{2-} \xrightarrow{\mathrm{OH}^{-}} \mathrm{SO}_{4}^{2-}

Fe+2⟶Fe+3\mathrm{Fe}^{+2} \longrightarrow \mathrm{Fe}^{+3}

S2O32−→H+S↓+SO42−\mathrm{S}_{2} \mathrm{O}_{3}^{2-} \xrightarrow{\mathrm{H}^{+}} \mathrm{S} \downarrow+\mathrm{SO}_{4}^{2-}

Answer key and solution verified before publishing.

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Exam
JEE Main 2025
Paper
28 January, Morning Shift
Subject
Chemistry
Chapter
d and f Block Elements
Topic
Compounds of Chromium

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