Question

In reduction of dichromate by $Fe\left(II\right)$, the number of electrons involved per chromium atoms is:

• A. 2
• B. 3
• C. 4
• D. 1

Answer 1

The correct option is B 3

Reduction process:
$C{r}_2{O}_7^{2-}+6e^{-}+14H^{+}\to 2C{r}^{3+}+7H_{2}O$
So, 3 electrons per $Cr$ atom is used.