Multiple Choice 0.2 points
Consider the following standard reduction potentials:
O$_2$(g) + 4H$^+$ (aq) + 4e$^-$ → 2H$_2$O (l) +1.23 V
Ni$^{2+}$(aq) + 2e$^-$ → Ni(s) -0.28 V
Fe$^{2+}$(aq) + 2e$^-$ → Fe(s) -0.45 V
Zn$^{2+}$(aq) + 2e$^-$ → Zn(s) -0.77 V
Which process will occur to act as a sacrificial anode for iron?
Ni (s) to Ni$^{2+}$ (aq)
2 H$_2$O (l) to O$_2$ (g)
Ni$^{2+}$ (aq) to Ni (s)
Zn (s) to Zn$^{2+}$ (aq)
Zn$^{2+}$ (aq) to Zn (s)
O$_2$ (g) to 2 H$_2$O (l)