Electrochemical Fruit/Vegetable Contest

(Download the MS Word version of this document.)

Purpose

The student should discover factors that relate to the largest potential difference when using different fruits/vegetables and several different electrodes.

Materials

• Voltmeters or multimeters (need to read millivolts) (CBL works great!)
• Various fruits/vegetables (brought from home by students)
• 2 leads with alligator clips per lab groups
• Various strips of metals (zinc, lead, copper, iron, magnesium, etc.)
• Metric ruler

Procedure

1. Insert two different metals 1.5 inches apart into the chosen fruit/vegetable.
2. Using the leads connect the metals to the voltmeter and measure the voltage.
3. Repeat this same procedure at 2 inches apart.
4. Record results.
5. Explore different fruits/vegetables with different metals. Record each trial into the data table.
6. The winner will be the group with the highest voltage when read from the teacher's voltmeter! Have fun and learn!

Lab Report Form

PURPOSE

(Stated in your own words)

QUESTIONS

Based on the experiment performed and your knowledge of electrochemistry, answer the following questions.

1. Which of the electrode materials was the anode and which was the cathode during the experiment? Explain your reasoning for each of the trials performed.

2. Suppose that you had not seen or performed the experiment. How could you predict which material would be the anode and which would be the cathode?

3. What variables should be considered for producing the highest voltage?

4. Does the potential difference depend on the kind of fruit/electrode used? Explain.

5. Does the potential difference depend on the amount of separation of the electrodes? Give reasons for your answer.

6. What electrodes appeared to have the highest potential difference? Why?

7. Compare your results with others. How do they compare? Was the highest potential difference with the same fruit? With the same electrodes? Explain.