CELLS AND BATTERIES
Learning Objectives
By the end of this lesson, students will:
· Understand and be able to discuss the arrangement of cells in batteries.
· Know the difference between primary and secondary cells.
· Be able to identify and contrast (similarities and differences) the different kind of batteries.
· Understand the societal implications of the manufacturing, the use, and the recycling of batteries.
· Understand and be able to discuss the arrangement of cells in batteries.
· Know the difference between primary and secondary cells.
· Be able to identify and contrast (similarities and differences) the different kind of batteries.
· Understand the societal implications of the manufacturing, the use, and the recycling of batteries.
Lesson Approaches and Overview (Specific Expectations: F1.1, F2.1, F3.4)
· The following video can be used to introduce the lesson, as it is about the hydrogen fuel buses used in Vancouver to transport the athletes. The Vancouver Olympic Games are an even that is very relevant, and current, to the students:
To accompany this video, the following article can be utilized:
· Perform a “Lightning-Round” game: Tell the students that this activity will be timed, and that it requires for them to be “on their” toes. Ask the students to put on their desks (or the middle of the table if students are seated in groups), any objects they have with them that run on batteries, or that require the use of batteries. Make it a game, give them 10 seconds, and count each second out loud. A first modification of this activity is to ask each student in a row, one after the other (in a fashion that maintains the sense of a “lightning-round”), to name anything that comes to mind that runs in batteries. A second modification, in case students are seated in tables, is to provide each group with a poster board and markers, and to ask them to write as many things as come to mind that run on batteries. Regardless of the modification, time should be short as to “spark” student’s motivation to learn more about batteries.
· Bring different types of batteries to class, and at the beginning of the class, ask students if they know what kind of batteries they are. This is a good way to spark the student’s interest, as well as to introduce some concepts that will be taught as part of the lesson.
· Bring a “dissected” 9V battery so that students can observe the arrangement of the cells. As stated in a previous lesson, handle the battery with care, as its components are caustic. Make sure to dispose of it properly.
· This lesson presents a valuable opportunity to relate chemistry advancements with historical figures. Teachers can spend some time talking about Luigi Galvani and Alessandro Volta, and pointing out how the concepts of voltage and “galvanic” cells were developed by them. This gives students a sense of chemistry in a historical context.
· A suggested PowerPoint presentation (and its accompanying worksheet) is presented here for the lecturing part of the lesson:
· Bring different types of batteries to class, and at the beginning of the class, ask students if they know what kind of batteries they are. This is a good way to spark the student’s interest, as well as to introduce some concepts that will be taught as part of the lesson.
· Bring a “dissected” 9V battery so that students can observe the arrangement of the cells. As stated in a previous lesson, handle the battery with care, as its components are caustic. Make sure to dispose of it properly.
· This lesson presents a valuable opportunity to relate chemistry advancements with historical figures. Teachers can spend some time talking about Luigi Galvani and Alessandro Volta, and pointing out how the concepts of voltage and “galvanic” cells were developed by them. This gives students a sense of chemistry in a historical context.
· A suggested PowerPoint presentation (and its accompanying worksheet) is presented here for the lecturing part of the lesson:
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· Here is a suggested activity for building a battery. It is an easy, quick activity that can be done as a hook if so desired:
buildabattery.pdf | |
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· List of suggested videos to be used during the lesson:
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· This lesson presents a valuable opportunity to relate chemistry advancements to historical figures, and provides an understanding of how scientific terminology comes about. Teachers can spend some time talking about Luigi Galvani and Alessandro Volta, and pointing out how the concepts of voltage and “galvanic” cells were developed by them. This gives students a sense of chemistry in a historical context.
· One of the most effective teaching strategies for this lesson is the actual “building” of batteries. The following webpages provide a list of links with information about building “fruity” batteries:
· One of the most effective teaching strategies for this lesson is the actual “building” of batteries. The following webpages provide a list of links with information about building “fruity” batteries:
Although the following experiment was designed for grade 6, its procedure and results are very relevant to the lesson:
· The following websites are good resources for lesson plans, as they contain background information, experimentation, and reflection questions:
· These lesson plans involve “dry” cells:
· The following is an interactive website. Please note that only Questions 1-8 are relevant to our lesson:
· This lesson provides many good opportunities to “tie-in” the STSE component of the Chemistry curriculum, especially when related to the issue of recycling batteries. Encourage students to research what happens to batteries that are discarded, how it affects the environment, and what “recycling” of batteries work. Students can research alternative ways of battery recycling.
· A useful analogy that can be use during the teaching of this lesson is this: Cells make up batteries. These cells are wired like beads in a necklace, with the anode of one cell connected to the cathode of the next cell.
· Remind students of the following basic concept:
Voltage = Sum of cell potentials. That is, the more cells a battery has, the more electrical energy is produced.
· Stress that the main, defining difference between primary and secondary cells is primary cells cannot be recharged, while secondary cells can.
· Suggested activity:
Create a table contrasting the advantages, disadvantages, the net reaction equations, and the uses of each type of battery: Alkaline dry cells, lead storage, lithium-ion, and fuel cells. Here is an example of such table:
· A useful analogy that can be use during the teaching of this lesson is this: Cells make up batteries. These cells are wired like beads in a necklace, with the anode of one cell connected to the cathode of the next cell.
· Remind students of the following basic concept:
Voltage = Sum of cell potentials. That is, the more cells a battery has, the more electrical energy is produced.
· Stress that the main, defining difference between primary and secondary cells is primary cells cannot be recharged, while secondary cells can.
· Suggested activity:
Create a table contrasting the advantages, disadvantages, the net reaction equations, and the uses of each type of battery: Alkaline dry cells, lead storage, lithium-ion, and fuel cells. Here is an example of such table:
· The following are links to websites which contain information about the different types of batteries:
· Here is an example of an inquiry activity that can be set-up by students to determine which one of the commercial batteries is more effective:
· The following is a link to a “battery development timeline.” This could be an activity assigned to the students, during which they research and create a timeline about the development of batteries:
· Have the students create a Concept Map of primary and secondary cells. An example is presented here (towards the end of the website):
· To tie the concepts presented in this lesson with the concepts on the rest of the unit, remind students that:
Recharging of batteries = Reversing the redox reaction.
· Remind students that discharging is a spontaneous process. Charging is a non-spontaneous process, which requires an external source of electrical energy. Use the following analogy: Discharging a battery is like allowing water to flow spontaneously from an open tap. Charging a battery is like pumping water uphill. This relationship can also be illustrated using a gravitational analogy, with the reactants represented at a higher level than the products. The spontaneous discharging process involves a loss of energy by the chemical system, while the non-spontaneous charging process involves a gain in energy.
· Be aware that this section introduces several SI units that may be new to students. Take time to explain the different quantities that these units are designed to measure. A concept which students may find most difficult to comprehend is electric potential (energy) difference. It is useful to apply analogies like the following: Discuss paper money transfer. Each bill is a transfer device (electron), the value of each bill is the potential (voltage), and the total money (energy) transfer depends on both the number of bills (number of electrons or charge) and the potential (value or energy) difference of each transfer unit.
· Ask students if they have done, seen, or read about how “dead” batteries in cars are recharged. This is a good opportunity to introduce the chemistry of lead storage batteries, and to relate this concept to the students’ real life. Talk about the safety concerns and procedures when “jumping” a car.
· Any of the activities suggested previously can be used for debrief/consolidation. However, students, either as homework or as in-class activities, can explore several issues that impact the environment, and/or their daily lives. For example, encourage students to research hydrogen fuel cells and how they work, their advantages and disadvantages. Ask students to think about what would happen when/or if the planet runs out of petroleum to run cars. Or, ask students to develop presentations about some of the societal implications of batteries, such as pacemakers, which would highlight the relevance of the concepts presented in this lesson.
Recharging of batteries = Reversing the redox reaction.
· Remind students that discharging is a spontaneous process. Charging is a non-spontaneous process, which requires an external source of electrical energy. Use the following analogy: Discharging a battery is like allowing water to flow spontaneously from an open tap. Charging a battery is like pumping water uphill. This relationship can also be illustrated using a gravitational analogy, with the reactants represented at a higher level than the products. The spontaneous discharging process involves a loss of energy by the chemical system, while the non-spontaneous charging process involves a gain in energy.
· Be aware that this section introduces several SI units that may be new to students. Take time to explain the different quantities that these units are designed to measure. A concept which students may find most difficult to comprehend is electric potential (energy) difference. It is useful to apply analogies like the following: Discuss paper money transfer. Each bill is a transfer device (electron), the value of each bill is the potential (voltage), and the total money (energy) transfer depends on both the number of bills (number of electrons or charge) and the potential (value or energy) difference of each transfer unit.
· Ask students if they have done, seen, or read about how “dead” batteries in cars are recharged. This is a good opportunity to introduce the chemistry of lead storage batteries, and to relate this concept to the students’ real life. Talk about the safety concerns and procedures when “jumping” a car.
· Any of the activities suggested previously can be used for debrief/consolidation. However, students, either as homework or as in-class activities, can explore several issues that impact the environment, and/or their daily lives. For example, encourage students to research hydrogen fuel cells and how they work, their advantages and disadvantages. Ask students to think about what would happen when/or if the planet runs out of petroleum to run cars. Or, ask students to develop presentations about some of the societal implications of batteries, such as pacemakers, which would highlight the relevance of the concepts presented in this lesson.
References
- Picture on top of page retrieved from: http://allthingsd.com/files/2011/11/ios-battery-loss.png
- Di Guiseppe, M., Haberer, S., Salciccioli, K., Sanader, M, Vavitsas, A. (2012) Chemistry 12. Toronto: Nelson Education Ltd.
- van Kessel, H., Jenkins, F., Davies, L., Plumb, D., Di Guiseppe, M., Lantz, O., Tompkins, D. (2003). Chemistry 12. Toronto: Thomson Canada Limited