Investigating Batteries: Building an Electrolytic Cell
In this inquiry, students will diagram the set-up of a student made battery lighting a bulb. Using zinc and copper electrodes, students will attempt to build an electrolytic cell which will cause a bulb to turn on. Students will report their results in a written lab report following the attached format. From this information, students will describe how they might determine the activity series of certain elements.
This activity is designed for students to work on designing an investigation to answer a question. By doing this activity, students will have formulated a question, designed a procedure, analyzed data and drawn conclusions. Included in this lab, students will experience voltage, solve a problem using the Nernst equation, and determine the flow direction of electrons in a battery.
Context for Use
This is the introduction to the electrochemistry unit for my honors chemistry class. Typically they are juniors and this would be during the fourth quarter of the school year. If more than 12 stations are necessary, it is important to do this over more than one day so that all students have access to handling materials (two per group). As written, this is a fairly simple inquiry that can be adapted for higher levels by adding more math and using a greater variety of electrode possibilities. If a specific equipment is unavailable, it is possible to find substitute material and simple battery parts from broken "stuff".
Subject: Chemistry:Inorganic Chemistry, Physics:Electricity & Magnetism
Resource Type: Activities:Lab Activity
Grade Level: High School (9-12)
Description and Teaching Materials
Students will be given a list of materials (including excess information) to attempt to build a battery that produces enough voltage to light a bulb. Batteries need to be between 1.5 and 3.0 volts to get the bulb to light. Anything less may not work. All parts must be hooked up in the correct order of the electron flow will be incomplete and the circuit will not work.
Question given to student: Can you design a battery that can do useful work? (ie – light a bulb)
Students should have a background in metallic properties and electron flow behavior from previous units. If not, this can be done as an assessment at the end of the unit on batteries.
Teaching Notes and Tips
Be sure to stress lab safety to your students. Although the batteries used cannot cause injury, all equipment should be respected for possible problems. If you teach multiple sections, be sure to have extra light bulbs available as some of them burn out fairly quickly. Also, test even the new bulbs as they sometimes don't work straight from the package.
Typically, students are given the directions on how to build a cell and materials are there for them. In this activity, students discover the different capacity of various molarities of solutions and the conductivity of different metals.
Students will be working as a pair for the initial investigation but will be required to individually draw the diagram and communicate in written form how the cell works and why using appropriate scientific vocabulary.
Students will turn in individual lab reports as well. Specific questions will be asked in the conclusion section.
2. Electrons respond to electric fields and voltages by moving through electrical circuits and this motion generates magnetic fields. 9P.22.214.171.124 Explain why currents flow when free charges are placed in an electrical field, and how that forms the basis for electrical circuits.
2. Energy can be transformed within a system or transferred to other systems or the environment, but is always conserved. 126.96.36.199.1 Identify the energy forms and explain the transfers of energy involved in the operation of common devices.
For example: Light bulbs, electric motors, automobiles or bicycles.
References and Resources