Explain your thinking, and calculate the cell potential.

Ca 2+ (aq) + 2e - Ca (s) E o pot = -2.87 V

Al 3+ (aq) + 3e - Al (s) E o pot = - 1.66 V

Hg 2+ (aq) + 2e - Hg (s) E o pot = +0.85 V

Au 3+ (aq) + 3e - Au (s) E o pot = +1.50 V

2.) When the switch is turned on, a wire connects the anode to the cathode. Do batteries require any energy to start the redox reaction? If not, what causes the electrons to transfer from one species to another?