Question

1. Consider a voltaic (galvanic) cell with the following metal electrodes. Identify which metal is the cathode and which is the anode, and calculate the cell potential.

(a) Al and Co(II)
Cathode: ____

Anode: ______

Ecell =

(b) Cd(II) and Ag(I)

cathode: ___

anode: ___

Ecell= ____

(c) Cr(III) and Sc(III)

cathode: ___

Anode:_____

Ecell:____

2. A voltaic cell contains two half-cells. One half-cell contains a titanium electrode immersed in a 1.00 M Ti(NO₃)₃ solution. The second half-cell contains a zinc electrode immersed in a 1.00 M Zn(NO₃)₂ solution.

Ti3+(aq) + 3 e− → Ti(s)	E⁰red  = −1.370 V
Zn2+(aq) + 2 e− → Zn(s)	E⁰red  = −0.762 V

(a) Using the standard reduction potentials given above, predict the standard cell potential of the voltaic cell.

(b) Write the overall balanced equation for the voltaic cell. (Include states-of-matter under the given conditions in your answer.)

3. ΔG° and E° can be said to measure the same thing, and are convertible by the equation

ΔG° = −nFE⁰cell 

where n is the total number of moles of electrons being transferred, and F is the Faraday constant 9.64853415 ✕ 10⁴ C/mol. The free energy (ΔG°) of a spontaneous reaction is always negative.

For each of the electrochemical cells below, calculate the free energy of the system and state whether the reaction is spontaneous or non-spontaneous as written based on the cathode and anode assignment given. (Use the table of Standard Electrode Potentials.)

(a) The cathode is Zn(II) and the anode is Co(II).

free energy: ____ kJ

spontaneity: _____