Question

In $FeC{r}_2{O}_4$ the oxidation numbers of Fe and Cr are:

• A. + 2 and + 3
• B. 0 and +2
• C. +2 and +6
• D. +3 and +6

Answer 1

The correct option is A + 2 and + 3

$FeC{r}_2{O}_4$

$Fe:x+6+(4\times -2)=0$

$\Rightarrow x=8-6$

$\Rightarrow x=+2$.

$Cr:2+2x+(4\times -2)=0$

$\Rightarrow 2x=8-2$

$\Rightarrow x=6/2$

$\Rightarrow x=+3$.