III. Cell Potentials Under Standard Conditions

A. Zinc – Copper

Zn(s), Zn(NO3)2 (1.0 M) || Cu(s), CuCl2 (1.0 M)

1. Draw the schematic of the electrochemical cell that includes all the components (metals, solutions, salt bridges, voltmeters, etc.). Annotate on the schematic which side is the anode, which side is the cathode, the sign of each half cell, the composition of the metals and solutions, and the direction of the flow of the electrons through the cell.

2. Write the half reactions that occur at the anode and cathode in this electrochemical cell. Annotate which half reaction occurs at the anode and the cathode.

3. Write the overall balance reaction of this electrochemical cell.

4. Calculate E°cell of this electrochemical cell. (include units)

E°cell

5. Calculate the reaction quotient (Q) of this reaction.

Q

6. Calculate the expected Ecell for this reaction.

Ecell

7. Record the value of Ecell measured for this reaction

Ecell 0.907

8. Calculate the percent error between the measured and calculated Ecell for this reaction. What are some of the possible sources of this error? Is the error value reasonable?

% error