Question

Br2 + 5NiO2+ 4H2O+ 2OH-2BrO3- + 5Ni(OH)2 In the above redox reaction, use oxidation numbers to identify the element oxidized, the element reduced, the oxidizing agent and the reducing agent? Please include the formula and element of reduced and oxidized.

Answer 1

As in $Br_2$ the oxidation state of $Br$ is

And in $BrO_3^{-1}$ the oxidation state $Br$ of is $+5$

Hence $Br_2$ is oxidized to $BrO_3^{-1}$ and $NiO_2$ is an oxidizing agent

As in $NiO_2$ the oxidation state of $Ni$ is $+4$

And in $Ni(OH)_2$ the oxidation state of $Ni$ is $+2$

Hence $NiO_2$ is reduced to $Ni(OH)_2$ and $Br_2$ is a reducing agent

The oxidation half reaction is $Br_2+12OH^{-1}\to2BrO_3^{-1}+10e^{-1}+6H_2O$

The reduction half reaction is $NiO_2+2H_2O+2e^{-1}\to Ni(OH)_2+2OH^{-1}$