Question

Question #7eb16

Answer 1

Copper metal is oxidized to `Cu^(2+)`. The nitrogen of nitric acid is reduced from `V+` to `II+`.

Explanation:

Oxidation half equation:

`Cu^0 rarr Cu^(2+) + 2e^-` `(i)`

`Hstackrel(+V)NO_3 +3e^(-) + 3H^(+) rarr stackrel(+II)NO +2H_2O` `(ii)`

Are both equation balanced with respect to mass and charge? I think they are (and they must be for a correct answer).

So now I cross multiply, `3xx(i)+2xx(ii)` (I do this to eliminate the electrons! which are included in the redox equations as conceptual particles):

`3Cu + 2HNO_3 + 6H^(+)rarr 3Cu^(2+) + 2NO + 4H_2O`

Of course, since I am producing `Cu(NO_3)_2(aq)` I could write:

`3Cu(s) + 8HNO_3(aq) rarr 3Cu(NO_3)_2(aq) + 2NO(g) + 4H_2O(l)`

The last hurdle: is this equation balanced with respect to mass and charge? I leave it to you to decide. I might have made a mistake.