Question

Which is the following changes does not require a reducing agent:

• A. $Cr{O}_4^{2-}\to C{r}_2{O}_7^{2-}$
• B. $Br{O}_3^{-}\to Br{O}^{-}$
• C. $\text{None of the above}$
• D. $H_2{O}_2\to O_2$

Answer 1

The correct option is A $Cr{O}_4^{2-}\to C{r}_2{O}_7^{2-}$

There is no change in the oxidation state of Cr in option (a), hence the reaction does not require a reducing agent.