Final answer:
The net cell reaction for an iron-silver voltaic cell is Fe(s) + 2Ag+ (aq) → Fe²+(aq) + 2Ag(s), and it is a spontaneous reaction due to the positive standard cell potential.
Step-by-step explanation:
The net cell reaction for an iron-silver voltaic cell involves iron being oxidized and silver ions being reduced. The balanced chemical equation for this reaction is:
Fe(s) + 2Ag+ (aq) → Fe²+(aq) + 2Ag(s)
Iron (Fe) acts as the anode, where oxidation occurs, and silver ions (Ag+) are at the cathode, where reduction takes place. To balance the charge, two electrons are transferred from iron to two silver ions, which become neutral silver atoms.
Considerations about the cell potentials:
The standard cell potential is positive, indicating a spontaneous reaction.
The silver ion reduction potential must be considered for the calculation but is not doubled in the equation directly.
The number of electrons lost in oxidation equals the number spent in reduction.