ChemistryJEE Main 24 Jan 2026, Shift 1·Q25·Numerical·Easy–moderate

Redox Reactions · Electrons transferred dichromate oxidation

X and Y are the number of electrons involved, respectively during the oxidation of $\ce{I^-}$ to $\ce{I2}$ and $\ce{S^{2-}}$ to S by acidified $\ce{K2Cr2O7}$ . The value of X + Y is .

(Consider the electrons transferred per mole of $\ce{K2Cr2O7}$ reduced in each reaction)

We corrected a printing error in the original paper

Assumption “(Consider the electrons transferred per mole of $\ce{K2Cr2O7}$ reduced in each reaction)” added; the source leaves it unstated (per $\ce{I2}$ /S formed it would be 2 + 2 = 4).

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See the full 24 Jan 2026, Shift 1 paper