Determine the standard potential for each cell and identify the reactions as spontaneous or nonspontaneous as written. Cd(s) + 2NO-3 (aq) + 4H+(aq) → Cd2+(aq) + 2NO2(g) + 2H2O(l)|

Answer 1

Cd(s) + 2NO-3 (aq) + 4H+(aq) → Cd2+(aq) + 2NO2(g) + 2H2O(l)

Looks like the half reactions are:

Cd(s) → Cd2+(aq)+2e- E=+0.403

NO₃^-+4H+ +2e-→2NO2+2H2O E=+0.80

So, Ecell=(+0.403V)+(+0.80V)

Ecell=1.203 V

Since Ecell is positive, it's spontaneous/thermodynamically favorable.

For galvanic/voltaic cells, the reaction is spontaneous and generates electricity:

E>1 (+E), K>1, G<0 (-G)

For electrolytic cells, the reaction is non spontaneous and requires electricity to be supplied via a current:

E<1 (-E), K<1, G>0 (+G)

I looked up the reduction potentials on chempendix.