Co6 Experiment: Electrochemistry: Objectives
Co6 Experiment: Electrochemistry: Objectives
Co6 Experiment: Electrochemistry: Objectives
OBJECTIVES
Figure 1
1. Construct the set-up shown in figure 1. Pour 50 mL of 0.5M cupric sulfate, CuSO 4 in a 150 mL
beaker.
2. Pour 50 mL of 0.5M zinc sulfate, ZnSO4 in a 150 mL beaker.
3. Attach the alligator clips on each copper wire cables to each metal strip (black wire cable to zinc
electrode and red wire cable to copper electrode)
4. Connect the red and black copper wire cables to the multimeter properly.
5. Set the multimeter to DCV 2000 condition.
6. Dip the salt bridge to the 2 solutions (50 mL of 0.5M cupric sulfate, CuSO 4 and 50 mL of 0.5M
zinc sulfate, ZnSO4)
7. Dip the copper electrode to the copper sulfate solution and dip the zinc electrode to the zinc
sulfate solution.
8. Measure the voltage produced between the two metal strips. Make sure to divide the measured
voltage by 1000. Record your observation.
Anode is an electrode where in oxidation takes place. Oxidation is the process of losing electron.
In the experiment, Zinc (Zn) has a higher potential to be oxidized than the Copper (Cu).
Therefore, Zinc (Zn) in the experiment acts as the anode while the Copper (Cu) acts as a cathode.
2. Why should the electrodes be placed in separate beakers containing their respective solutions?
To produce a voltage gradient, electrodes are placed into separate beakers based on their given
solutions. In one beaker, positive VE change is developed through the process of oxidation while
there is a negative VE change occurred through the process of reduction. When the two solutions
are combined, there will be no gradient and the cell will not work because the exchange of the
electrons will only be possible if the solutions are separated.
3. Write the half-cell reaction that took place in the zinc electrode.
4. Write the half-cell reaction that took place in the copper electrode.
2 +¿
C u(aq) +2 e → Cu(s ) ¿
6. What was the measured cell voltage for this voltaic cell?
1.082 V
7. Write the cell notation for this cell.
8. Using the Standard Reduction Potential Table, calculate the standard cell voltage for this cell.
E°Zn2+/Zn = -0.76 V
E°Cu2+/Cu = +0.34 V
And E° cell = E° cathode - E° anode = 0.34 - (-0.76) = +1.10 V
Measured −Calculated
|
9. Calculate the percentage difference. % difference = Measured +Calculated
2
|
1.082−1.10
| 1.082+1.10
2 |X 100
= 1.649862511
10. What are the possible causes of the difference between the measured value and the calculated
value.
Many factors may affect the difference between the measured value and the calculated value.
Some factors such as the temperature, pressure and concentrations may not be accurately
measured during the experimentation. These factors may then affect the result of the experimental
value, resulting to a high difference between the experimental and theoretical value.