What is "nascent oxygen", and how does it relate to potassium permanganate?

Sep 10, 2017

$\text{Nascent oxygen}$ is a bit of an old-fashioned term......

Explanation:

But you really just need to heat up $\text{potassium permanganate}$: oxygen (as oxide) is oxidized, and manganese is reduced......

$M n {O}_{4}^{-} + 4 {H}^{+} + 3 {e}^{-} \rightarrow M n {O}_{2} \left(s\right) + 2 {H}_{2} O$ $\left(i\right)$

${O}^{2 -} \rightarrow \frac{1}{2} {O}_{2} \left(g\right) + 2 {e}^{-}$ $\left(i i\right)$

And so take $2 \times \left(i\right) + 3 \times \left(i i\right)$

$2 M n {O}_{4}^{-} + {\underbrace{8 {H}^{+} + 3 {O}^{2 -}}}_{3 {H}_{2} O + 2 {H}^{+}} + 6 {e}^{-} \rightarrow 2 M n {O}_{2} \left(s\right) + 4 {H}_{2} O + \frac{3}{2} {O}_{2} \left(g\right) + 6 {e}^{-}$

And we cancel out common reagents.....

$2 M n {O}_{4}^{-} + 2 {H}^{+} \rightarrow 2 M n {O}_{2} \left(s\right) + {H}_{2} O + \frac{3}{2} {O}_{2} \left(g\right)$

Charge and mass are balanced as is required.......

We could look at this another way, and consider the decomposition of (shortlived!) permanganic acid:

$2 H M n {O}_{4} \rightarrow 2 M n {O}_{2} \left(s\right) + {H}_{2} O + \frac{3}{2} {O}_{2} \left(g\right)$