3) Using a table of standard reduction potentials, calculate (A) the standard cell potential?

Question

(electromotive force) in volts, and (B) the standard free energy change in kJ/mol, for the following cell reaction:

2Ag+ + Zn = 2Ag + Zn2+

Answer 1

Lancenigo di Villorba (TV), Italy

Your question interests a REDOX REACTION, as the following one :

Zn(s) + 2 Ag+(aq) ---> Zn++(aq) + 2 Ag(s)

As you will see, I may assume NOT the equilibrium since SILVER ION tends to convert as in COMPLETE FASHION.
In a RIGOROUS TREATISON, this system is able to join at ITS OWN CHEMICAL EQUILIBRIUM.
The Standard Conditions as you request interest the Molarity's Salts, so I HAVE TO ASSUME 1 M's SOLUTION's FOR ANY THE REACTANTs, e.g. |Ag+| = 1 M.
W. H. Nernst gave the Electrodic Potentials as measured at the Standard Conditions, as follows

Ag+(aq) + e ---> Ag(s)..............E° = +0.79 V
Zn++(aq) + 2e ---> Zn(s)...........E° = -0.76 V

respectively referred to |Ag+| = 1 M.
The STANDARD CELL POTENTIAL as E.M.F. IS EQUAL THAN THE POTENTIAL's DIFFERENCE

DeltaE° = E°cathode - E°anode

stating that CATHODE HAVE THE GREATEST POTENTIAL while ANODE HAVE THE LOWEST ONE : hence

DeltaE° = (+0.79) - (-0.76) = +1.55 V

J. E. van't Hoff overcame to the "Gibb's-Nernst Relationship" which relates E.M.F. to GIBB's FREE ENERGY

DeltaG° = 0 - n * F * DeltaE° = 0 - 2 * 96,500 * (+1.55) =
= -299,150 J/mol

I hope this helps you.

Answer 2

Standard Emf Table

Answer 3

use equation Ecell=Eredu-Eoxi

Ecell=2.87-(-.44)
=3.31 V

-299.15 kJ/Mol