Book: KE & R: 21

Question 1

Relating the spontaneity of a process to the sign of the cell potential.

Answer 1

E_cell > 0 for a spontaneous process

Question 2

Relating electric potential to energy and charge in SI units.

Answer 2

Potential = energy / charge or 1 V = 1 J / C

Question 3

Relating standard cell potential to standard electrode potentials in a voltaic cell.

Answer 3

Eº_cell = Eº_cathode(reduction) - Eº_anode(oxidation)

Question 4

Defining the Faraday constant.

Answer 4

F = 9.65×10⁴ J / V mol e⁻

Question 5

Relating the free energy change to the cell potential.

Answer 5

∆G = -n F E_cell

Question 6

Finding the standard free energy change from the standard cell potential.

Answer 6

∆Gº = -n F Eº_cell

Question 7

Finding the equilibrium constant from the standard cell potential.

Answer 7

Eº_cell = ( R T ln( K ) ) / ( n F )

Question 8

Substituting known values of R, F, and T into equation Eº_cell = ( R T ln( K ) ) / ( n F ) and converting to a common logarithm.

Answer 8

Eº_cell = ( 0.0592 V / n ) log K or log K = n Eº_cell / 0.0592 V

Question 9

Calculating the nonstandard cell potential (Nernst equation).

Answer 9

E_cell = Eº_cell - RT ln Q / n F

Question 10

Substituting known values of R, F, and T into the Nernst equation and converting to a common logarithm.

Answer 10

E_cell = Eº_cell - ( 0.0592 V / n ) log Q

Question 11

Relating current to charge and time.

Answer 11

current ( A ) = charge ( C ) / time ( s )