Chemistry - Redox Reactions Question with Solution | TestHub

$\stackrel{\mathrm{*}}{\mathrm{C}}\mathrm{r}{\mathrm{O}}_4^{2-}$$\stackrel{\mathrm{*}}{\mathrm{C}}{\mathrm{r}}_2{\mathrm{O}}_7^{2-}$
$\mathrm{x}+\left[\right(-2)\times 4]=-2$$2\mathrm{x}+(-2)\times 7=-2$
$\mathrm{x}=8-2=+6$$2\mathrm{x}=14-2=12$,
$\mathrm{x}=\frac{12}{2}=+6$
In this reaction oxidation and reduction are not involved because there is no change in oxidation number.