Question

Answer the following questions that relate to electrochemical reactions. (a) Under standard conditions at 25˚C, Zn(s) reacts with Co2+(aq) to produce Co(s). (i) Write the balanced equation for the oxidation half reaction. (ii) Write the balanced net-ionic equation for the overall reaction. (iv) Calculate the standard potential, E˚, for the overall reaction at 25˚C.

Answer 1

Answer:

0.48 V

Explanation:

Zn(s) ------------> Zn^2+(aq) + 2e. Oxidation half equation (-0.76V)

Co^2+(aq) + 2e-----------> Co(s). Reduction half equation (-0.28)

Zn(s) + Co^2+(aq) -------------> Zn^2+(aq) + Co(s) overall redox equation

Zinc is the anode while cobalt is the cathode.

E°cell= E°cathode - E°anode

E°cell= -0.28-(-0.76)= 0.48 V

Answer 2

Answer:

Explanation:

Half cell equations:

Oxidation

Zn(s) --> Zn2+(aq) + 2e-

E° = 0.7618 V

Reduction

Co2+(aq) + 2e- --> Co(s)

E° = -0.28 V

Balanced net ionic equation

Co2+(aq) + Zn(s) --> Zn2+(aq) + Co(s)

Standard electrode potential, E°cell = E°cathode - E°anode

For an electrochemical reaction,

Standard electrode potential, E°cell = E°reduction - E°oxidation

= -0.28 - (0.7618)

= -1.0418 V