JEE Main 2026 · 2 Apr · Shift 1 · Chemistry Q61

ChemistrySingle correct+4 / -1Question 61 of 75

Which of the following sets includes all the species that will change the orange colour of $\ce{K2Cr2O7}$ in acidic medium ?

\ce{Fe^{2+}}

\ce{Sn^{2+}}

\ce{I-}

\ce{S^{2-}}

\ce{S^{2-}}

\ce{Fe^{3+}}

\ce{I-}

\ce{C2O4^{2-}}

\ce{Fe^{2+}}

\ce{NO2-}

\ce{SO2}

\ce{Sn^{4+}}

\ce{Fe^{3+}}

\ce{SO4^{2-}}

\ce{S^{2-}}

\ce{Sn^{4+}}

Answer and worked solution

Official answer: A

Reducing agents turn orange $\ce{Cr2O7^{2-}}$ green ( $\ce{Cr^{3+}}$ ).

(A) $\ce{Fe^{2+}}$ , $\ce{Sn^{2+}}$ , $\ce{I-}$ and $\ce{S^{2-}}$ are all reductants ✓
(B) $\ce{Fe^{3+}}$ is not a reductant.
(C) $\ce{Sn^{4+}}$ is not a reductant.
(D) $\ce{Fe^{3+}}$ , $\ce{SO4^{2-}}$ and $\ce{Sn^{4+}}$ are not reductants.

(A)

Topics:Important compounds (KMnO4, K2Cr2O7)Oxidation number

JEE Main 2026 · 2 Apr · Shift 1, Chemistry question 61