LOGO - PULSE



The Energy Debate - Energy of Peanut

Written for PULSE by Christopher Martin
Edited By: Stephanie Nardei



Time: One class period
Preparation
Time:

20 minutes

Materials:

Lab - Energy of a peanut
Boiling tube
Thermometer
Peanuts
Balance
Cork with pin
Measuring cylinder
Bunsen Burner
Selection of fuels

Abstract
Students will learn that a tiny peanut contains stored chemical energy. When we eat them, the stored energy is converted by our bodies so we can do work. We can also use the energy in a peanut to heat a container of water.

Objectives
Students will be able to:

  1. Articulate the difference between the terms heat and temperature
  2. Calculate the amount of energy associated with a given temperature rise
  3. Design an experiment to measure the energy of a fuel

National Science Education Standard
CONTENT STANDARD E: The Physical Setting
Energy Transformations
Different energy levels are associated with different configurations of atoms and molecules. Some changes of configuration require an input of energy whereas others release energy.

Strand 5: Physical Science
Concept 4: Chemical Reactions
Investigate relationships between reactants and products in chemical reactions.
PO.10
Explain the energy transfers within chemical reactions using the law of conservation of energy.


Concept 3: Conservation of energy and increase in disorder.
PO.6 Distinguish between heat and temperature.

Teacher Background
--

Related and Resource Websites
Science Help Online Chemistry http://www.fordhamprep.com/gcurran/sho/sho/lessons/lesson17.htm
Science Projects Peanut Power http://www.energyquest.ca.gov/projects/peanut.html (image taken from here)
Energy of a Peanut: An Experiment in Calorimetry By David Katz http://www.chymist.com/energy%20of%20a%20peanut.pdf

The Energy Inside a Peanut http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/energy/peanut.html

 


Activity

  1. Start class by asking students to define what energy is. Students may suggest different forms of energy.  Dependent upon the background of your students you may wish to ask them to explain how each form of energy differs. How do you measure different amounts of heat energy?  What scales are used for measuring differences in heat?
  2. Explain to the class that the energy of a fuel can be measured by using the fuel to heat water. The specific heat capacity of water is 4.2 J/g/C. This means that it takes 4.2 Joules of energy to cause the temperature of 1 gram of water to rise by 1 degree Celsius.
  3. In this lab the students will use a peanut as a fuel to heat the water. What other fuels could be used?
  4. The teacher will demonstrate the lab reminding students to be work safely with the    Bunsen burner and to ensure that the cork doesn’t ignite with the peanut.
  5. Students should follow the instructions on the worksheet to measure the energy of a peanut. In conclusion, students should write “The fission of 1 gram of uranium 235 releases 78.5 Giga Joules of energy. The energy of one gram of peanut is ……… joules.”
  6. Finally, students will design a new lab to find the energy of another fuel. This will be completed in the second class period. Students should be advised to increase the volume of water with fuels of higher energy content.

Embedded Assessment
Students shall be assessed on their lab report for the energy of a peanut. Understanding of the formula to calculate energy should be a vital part of the grade. Ability to follow directions and work safely will be provide observed assessment. Finally, the design of a second lab will assess the students’ understanding of energy measurements as they transfer skills to test a new fuel.

 

 

 


PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:


an
NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award

LOGO - SWEHSC
LOGO - NIEHS Center LOGO - NIEHS

Supported by NIEHS grant # ES06694


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Last update: March 7, 2007
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