Calculate E°cell and indicate whether the overall reaction shown is spontaneous or nonspontaneous. O2(g) + 4H+(aq) + 4e- Picture 2H2O(l); E° = 1.229 V Al3+(aq) + 3e- Picture Al(s); E° = -1.662 V Overall reaction: 4Al(s) + 3O2(g) + 12H+(aq) ? 4Al3+(aq) + 6H2O(l) Answers: E°cell = -2.891 V, nonspontaneous E°cell = -2.891 V, spontaneous E°cell = 2.891 V, nonspontaneous E°cell = 2.891 V, spontaneous Spontaneous, but none of these values of E°cell is correct.