Question

Potassium dichromate is a good oxidising agent in acidic medium, the oxidation state of chromium changes by :

• A. 2
• B. 3
• C. 4
• D. 5

Answer 1

The correct option is B 3

Potassium dichromate is a powerful oxidizing-agent in acidic medium.

$C{r}_2{O}_7^{2-}+14H^{+}+6e^{-}⟶2C{r}^{3+}+7H_{2}O$

Oxidation number convert $+6$ to $+3$.

So, the answer is B.