Potassium dichromate acts as a strong oxidising agent in an acidic medium. When it reacts with exces

Question

Potassium dichromate acts as a strong oxidising agent in an acidic medium. When it reacts with excess iodide ions ($	ext{I}^-$), what are the products formed?

Professor PC Thomas Classes · Answer

In an acidic medium, $	ext{Cr}_2	ext{O}_7^{2-}$ oxidises iodide ions ($	ext{I}^-$) to free iodine ($	ext{I}_2$) and is itself reduced to $	ext{Cr}^{3+}$. The equation is: $	ext{Cr}_2	ext{O}_7^{2-} + 14	ext{H}^+ + 6	ext{I}^- ightarrow 2	ext{Cr}^{3+} + 3	ext{I}_2 + 7	ext{H}_2	ext{O}$.