,
Ecell = Eright  – Eleft
This is illustrated by the following example:
Cell reaction:
Cu(s) + 2Ag+(aq) ¾® Cu2+(aq) + 2 Ag(s)
(2 4)
Half-cell reactions:
Cathode (reduction):   2Ag+(aq) + 2e– ® 2Ag(s)
(2 5)
Anode (oxidation):    Cu(s)  ® Cu2+(aq) + 2e–
(2 6)
It can be seen that the sum of (3