Question

For the following electrochemical cell
Co(s) |Co^2+(aq, 0.0155 M)| |Ag^+(aq, 2.50 M)| Ag(s)
write the net cell equation. Phases are optional. Do not include the concentrations.
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
Calculate the following values at 25.0°C using standard reduction potentials as needed.
E°cell= _ _ _ _ _ _ V
∆G°rxn= _ _ _ _ _ _ kJ/mol
Ecell= _ _ _ _ _ _ V
∆Grxn= _ _ _ _ _ _ kJ/mol

Answer 1

From the given electrochemical equation it is evident that cobalt is the anode(left side) and silver is the cathode(right side)

THE TOTAL NUMBER OF ELECTRONS INVOLVED IN THE REDOX REACTION, (n) = 2 .

THE STANDARD ELECTRODE POTENTIAL, E₀   = E_cathode - E _anode = 0.080-(- 0.28) ( 0.80 v is the standard electrode potential of the silver electrode and -0.28V is the standard electrode potential of the Cobalt electrode.)

Thus , E₀   = E_cathode - E _anode =     1.08 V

SO STANDARD FREE ENERGY ,DELTA G⁰ = -nFE₀ = - 2* 96500 coloumbs/mole *1.08 = -208.44 KJ/mole

ELECTROMOTIVE FORCE OF THE CELL, Ecell

              = E₀ - 0.0591/n (log concentration of products/concentration of reactans) ---BY NERNST EQUATION)

               = 1.08 V - 0.03((log 0.0155/2.50) -- as per given concentrations    

               =1.4567 V

SO , FREE ENERGY OF THE CELL AS PER THE GIVEN CONCENTRATIONS

                                       DELATA G = - n *F* Ecell = - 2* 96500 * 1.4567 = -281.143 kj/mole

note 1 KJ = 1000 joules

PLEASE NOTE IN THE PROBLEM DELTA G/ OR/ DELTA G AT STANDARD CONDITIONS CALCULATED. THERE IS SOME DIFFERENT NOTATION PRESENT THERE WHICH IS PRESENTING AMBIGUITY LIKE rxn, OTHERWISE PROBLEM SOLVED)(