Question

What is the oxidation no of water?

Answer 1

Water DOES not have an oxidation number..

Explanation:

The constituent elements in water do have oxidation numbers...and the SUM of their oxidation numbers in the element equals the charge of the water molecule, i.e. here ZERO...because water is a neutral molecule...

And we can represent the redox reaction that forms water in this way..

`stackrel(0)H_2(g) + 1/2stackrel(0)O_2(g)rarrstackrel(+I)H_2stackrel(-II)O`

Dihydrogen is conceived to be oxidized....

`1/2H_2(g) rarr H^+ +e^(-)` `(i)`

And dioxygen is conceived to be reduced....

`1/2O_2(g) +2e^(-) rarr O^(2-)` `(ii)`..

And we take `2xx(i)+(ii)` to give..

`H_2(g) +1/2O_2(g) +2e^(-)rarr underbrace(2H^+ +O^(2-))_"i.e. one water molecule"+2e^(-)`

else..`H_2(g) +1/2O_2(g) rarr H_2O(l)`