JEE Main202623 January 2026Evening ShiftChemistryd and f Block ElementsActual
The oxidation state of chromium in the final product formed in the reaction between KI and acidified K ₂ Cr ₂ O ₇ solution is:
Options
- A+6
- B+3
- C+4
- D+2
Correct answer
B. +3
Step-by-step solution
In the reaction between KI and acidified K₂Cr₂O₇ , Cr in the dichromate ion exists in +6 oxidation state. Iodide ions are oxidized to I₂ while chromium is reduced. The reduction product is Cr³⁺ ions, which form chromium(III) salts like Cr₂(SO₄)₃ or coordination complexes. Therefore, the oxidation state of chromium in the final product is +3.