Question

Hydrogen peroxide oxidises $[Fe(CN)6]^{4-}$ to $[Fe(CN)6]^{3-}$ in acidic medium but reduces $[Fe(CN)6]^{3-}$ to$[Fe(CN)6]^{4-}$ in alkaline medium. The other products formed are, respectively

• A. $(H_2O + O_2)$ and $H_2O$
• B. $(H_2O + O_2)$ and $(H_2O + OH^{-})$
• C. $H_2O$ and $(H_2O + O_2)$
• D. $H_2O$ and $(H_2O + OH^{-})$

Answer 1

Answer: (C)

$H_2O$ and $(H_2O + O_2)$

Answer 2

$\left[ Fe ( CN )_{6}\right]^{4-}+\frac{1}{2} H _{2} O _{2}+ H ^{+} \longrightarrow\left[ Fe ( CN )_{6}\right]^{3-}+ H _{2} O$
$\left[ Fe ( CN )_{6}\right]^{3-}+\frac{1}{2} H _{2} O _{2}+ OH ^{\ominus} \rightarrow\left[ Fe ( CN )_{6}\right]^{4-}+ H _{2} O +\frac{1}{2} O _{2}$