Question

The oxidation state of chromium in the final product formed by the reaction between $KI$ and acidified potassium dichromate solution is

• A. 3
• B. 2
• C. 6
• D. 4

Answer 1

Answer: (A)

3

Answer 2

$Cr _{2} O _{7}^{2-}+14 H^{+}+6 I^{-} \rightarrow 2 Cr ^{3+}+7 H _{2} O +3 I _{2} Cr _{2} O _{7}^{2-}$ is reduced to $C r^{3+}$. Thus, final state of $Cr$ is $+3$.