The oxidation state of chromium in the final product formed by the reaction between KI and acidified…

In acidic medium ${\mathrm{Cr}}_2{{{\mathrm{O}}_7}^{-2}}^{}$ reduced in${\mathrm{Cr}}^{{+3}^{}}$  and ${\mathrm{I}}^{-}$ oxidise in ${\mathrm{I}}_2$.

${{\mathrm{C}\mathrm{r}}_2\mathrm{O}}_7^{2-}+14{\mathrm{H}}^{+}+6{\mathrm{I}}^{-}⟶2{\mathrm{C}\mathrm{r}}^{3+}+7{\mathrm{H}}_2\mathrm{O}+3{\mathrm{I}}_2$

${\mathrm{C}\mathrm{r}}_2{\mathrm{O}}_7^{2-}$is reduced to${\mathrm{C}\mathrm{r}}^{3+}.$

Thus, final state of $\mathrm{Cr}$ is $+3$.