Question

Potassium dichromate is used

• A. in electroplating
• B. as a reducing agent
• C. it oxidizes ferrous ions into ferric ions in acidic media as an oxidizing agent
• D. as an insecticide

Answer 1

Answer: (C)

Potassium dichromate is an oxidizing agent it oxidizes ferrous ions into ferric ions in acid medium.
$C{r}_2{O}_7^{2-}+14H^{+}+6e^{-}⟶2C{r}^{3+}+7H_{2}O$
$[F{e}^{2+}⟶F{e}^{3+}+e^{-}]\times 6$
$C{r}_2{O}_7^{2-}+6F{e}^{2+}+14H^{+}⟶$
$6F{e}^{3+}+2C{r}^{3+}+7H_{2}O$