Question

What are the oxidation and reduction equations for the following equations: Zn(s) + 2H2O(l) → Zn(OH)2(s) + H2(g) ?

Answer 1

`Zn(s) + 2HCl(aq) rarr ZnCl_2(aq) + H_2(g)uarr`

Explanation:

Zinc can be readily oxidized.........

`Zn(s) rarr Zn^(2+) + 2e^(-)` `(i)`

Hydrogen ion, as the `"acidium ion"` in water is commonly represented as `H_3O^+`, or even, more simply as `H^+`. Let's take the former..........

`H_3O^+ + e^(-) rarr1/2H_2(g) + H_2O(l)` `(ii)`

We add the individual redox equations in such a way that electrons do NOT appear.........i.e. `(i) + 2xx(ii)`

`Zn(s) +2H_3O^+ rarr Zn^(2+) + 2H_2O(l) + H_2(g)uarr`

Charge is balanced, and mass is balanced, as is required for any stoichiometric equation...........any representation of reality.