# Does oxidation cause an increase or decrease in mass?

Jun 23, 2017

Well formally yes........

#### Explanation:

Because oxidation represents the formal LOSS of electrons.....

$N a \left(s\right) \rightarrow N {a}^{+} + {e}^{-}$

And since electrons have definite (admittedly negligible) mass, this is a formal mass loss.

Of course for every oxidation there is a corresponding reduction , so certainly mass is conserved in the overall redox equation.

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

and the overall reaction is........

$N a \left(s\right) + {H}_{2} O \left(l\right) \rightarrow N a O H \left(a q\right) + \frac{1}{2} {H}_{2} \left(g\right)$