1. (a) Write the reactions for the discharge and charge of a nickel-cadmium rechargeable battery.
(b) Given the following reduction potentials, calculate the standard emf of the cell:
(i) Cd(OH)2(s) + 2 e- ---> Cd(s) + 2 OH-(aq) <-> Eored = -0.76 V
(ii) NiO(OH)(s) + H2O(l) + e- ---> Ni(OH)2(s) + OH-(aq) <-> Eored = +0.49 V
(c) A typical nicad voltage cell generates an emf of +1.30 V. Why is there a difference between this value and the one you calculated for part (b);
2. A common shorthand way to represent a voltaic cell is to list its components as follows:
anode|anode solution||cathode solution|cathode
A double vertical line represents a salt bridge or a porous barrier. A single vertical line represents a change in phase, such as from solid to solution.
(a) Write the half reactions and overall cell reaction represented by
Fe|Fe2+||Ag+|Ag
(b) Write the half reactions and overall cell reaction represented by
Zn|Zn2+||H+|H2
(c) Using the notation just described above, represent a cell based on the following reaction:
ClO3-(aq) + 3 Cu(s) + 6 H+(aq) ---> Cl-(aq) + 3 Cu2+(aq) + 3 H2O(l)
Pt is used as an inert electrode in contact with the ClO3- and the Cl-
(b) Given the following reduction potentials, calculate the standard emf of the cell:
(i) Cd(OH)2(s) + 2 e- ---> Cd(s) + 2 OH-(aq) <-> Eored = -0.76 V
(ii) NiO(OH)(s) + H2O(l) + e- ---> Ni(OH)2(s) + OH-(aq) <-> Eored = +0.49 V
(c) A typical nicad voltage cell generates an emf of +1.30 V. Why is there a difference between this value and the one you calculated for part (b);
2. A common shorthand way to represent a voltaic cell is to list its components as follows:
anode|anode solution||cathode solution|cathode
A double vertical line represents a salt bridge or a porous barrier. A single vertical line represents a change in phase, such as from solid to solution.
(a) Write the half reactions and overall cell reaction represented by
Fe|Fe2+||Ag+|Ag
(b) Write the half reactions and overall cell reaction represented by
Zn|Zn2+||H+|H2
(c) Using the notation just described above, represent a cell based on the following reaction:
ClO3-(aq) + 3 Cu(s) + 6 H+(aq) ---> Cl-(aq) + 3 Cu2+(aq) + 3 H2O(l)
Pt is used as an inert electrode in contact with the ClO3- and the Cl-