Developing a Daniell Cell Using Metal Foil and a PP Bag

Abstract

In many experiments for students using the Daniell cell, it is easy for the students to observe that the anode (Zn) turns black within one school hour as the cell is discharged. However, it is not easy for them to recognize the dissolution of the anode, or the phenomenon that the zinc metal changes into ions in the anode reaction. In this study, we first clarified that the formation of black substance on the anode is not caused by the electrode reaction, and developed a new teaching material “metal foil Daniell battery” that clearly showed the change of the electrode within 30 minutes. Then, after giving a lesson using this material to students in the third year of junior high school, a free-description questionnaire was conducted. 73.3% of the students who used this material mentioned a change in the shape of the anode (Zn). Only 11.1% of students who used previous materials mentioned shape changes, and 70.4% only described color changes. Thus, it was made clear that the teaching material developed in this study helped students understand the anode reaction based on their own observation.