May/June 2017 – Vol. 29 No. 7

Energy in Chemical Reactions Lab

Posted: Friday, October 1st, 2010

by Jeff Bradbury and Patricia Buchanan

Name ____________________

Date _____________________

Partner’s Name_____________

Question: Food provides us with energy to live, but how much of this energy can actually be found in a single peanut?

Purpose: To determine the heat of a chemical reaction.

Part 1 Introduction

Background Information:

1.       What is a calorie?

A Calorie is a unit of heat.  It is the amount of heat needed to raise the temperature of 1 gram of water 1 degree Celsius.  You will actually measure the calories of a food product and compare this to the calories on the container.  Food Calories usually have an upper case C.  1 Calorie = 1000 calories.  Today you will measure calories and then convert them to Calories.

2.       How are heat and temperature different?

Temperature is the average amount of kinetic energy contained in the molecules of a substance.  It is measured with a thermometer and the units are degrees Celsius.  Heat is the total amount of energy in a sample of substance.  It is measured indirectly and the units are calories.

3.       How is heat measured?

To measure calories in food, for example, the food is burned in a combustion chamber.  The heat from the combustion reaction of the food is used to raise the temperature of a sample of water.  Knowing the mass of the water and the temperature change of the water the heat gained by the water can be calculated using the following equation:

M X C X ΔT = Heat change in the water (q)

M is the mass of the water.  Δ T is the final temperature of the water—the initial temperature of the water (Δ T means change in temperature).  C is a constant called specific heat.  It tells how a particular substance absorbs heat.  All substances absorb heat differently.  It takes one calorie of heat to raise the temperature of one gram of water one degree Celsius.  C for water is 1 cal/g oC.


125 grams of water are heated by burning a sample of sugar.  The temperature of the water goes from 21 oC to 76 oC.  How much heat did the water absorb?  How much heat did the sugar release?

Answer Absorbed:____________________ Released: ____________________


Safety goggles must be worn at all times.  Be careful when lighting a burner.

Part 2 Procedure

Procedure, Observations, and Data:

In this lab you will be working in groups of two.

1. Measure the mass of the apparatus, which is a wire that is attached to a cork

2. Place 1/2 of a peanut on the apparatus and find the mass.

3. Put exactly 25 ml of water in a 100 ml beaker.  Measure and record the temperature of the water.

4. Light the peanut on fire with a Bunsen burner, and once the peanut is lit, quickly hold the beaker of water over the peanut.  The goal is to get as much heat into the water as possible.  (Is it possible to get all of the heat into the water?)

5. Do not let the water boil!  Blow out the flame before this happens.

6. After the peanut has burned, make sure the water is mixed so that the hot water is evenly dispersed in the beaker, and measure the temperature of the water and record.

7. Record the mass of the apparatus and peanut after it was burned.  Be sure to pick up any crumbs that fell off of the wire.

8. Repeat this experiment until you have burned two peanuts.

Table 1:  Mass and Temperature Changes in a Chemical Reaction

Mass of apparatus Mass of apparatus and peanut (initial) Mass of apparatus and peanut (final) Temperature of water (initial) Temperature of water (final) Mass of water used

Part 3 Calculations (Do this for each peanut)

Show all of the calculations for one nut in your lab book but show the results of all calculations in a table in your book

1. What is the initial mass of the peanut?

2. What is the final mass of the peanut?

3. What is the change in mass of the peanut?

4. What is the change in temperature of the water?

5. What is the heat gain of the water in calories?

6. What is the heat gain of the water in Calories?

7. What is the experimental heat loss of the peanut in Calories?

8. What is the heat loss per gram of the peanut?

9. What is the average heat loss per gram of the peanut?

10. What is the theoretical heat loss per gram of the peanut in Calories? (from the average)

11. What is the efficiency of this experiment? (from the average)

Table 2:  Calculating Heat Changes in a Chemical Reaction

Initial mass of peanut Final mass of peanut Change in mass of peanut Change in temp. of water Heat gain of water cal. Heat gain of water Cal. Experimental heat loss of peanut in Cal. Experimental heat loss per gram of peanut in Cal. Ave. heat loss of peanut Theo. heat loss of peanut % Eff.


1. How could you make it so that more of the heat from the burning peanut goes into the water

2. The mass of the peanut went down and the temperature of the water went up.  Did you change matter into energy?  Make sure you explain your answer with evidence.

3. What happened to the matter of the peanut that was burned?

4. How did the energy get into the peanut in the first place?

Jeff Bradbury is a Professor of Chemistry at Cerritos College in Norwalk; Patricia Buchanan is the Cal Grip Grant Project Assistant at Cerritos College.  The original idea for this activity came from the Los Angeles County Office of Education 15 years ago, which the authors modified.

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

One Response

  1. As a chemistry teacher of 30 years I have to say that with the number of students who have peanut allergies these days this lab has been modified by most of us to use other food sources from cheerios to cheetos but ANYTHING except NUTS
    If a kid is allergic and inhales the smoke from the peanut he will end in the hospital
    The questions on this lab are well thought out but PLEASE change the food source!
    It can also be done simply and easily with candles as the FUEL if you are not talking food energy but rather alternative fuels along with ethanol–just a few drops in a dish.
    I use an aluminum can to hold over the flame with a ring stand adn can even build an insulating chinmey

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CSTA Annual Conference Early Bird Rates End July 14

Posted: Wednesday, July 12th, 2017

by Jessica Sawko

Teachers engaged in workshop activity

Teachers engaging in hands-on learning during a workshop at the 2016 CSTA conference.

Don’t miss your chance to register at the early bird rate for the 2017 CSTA Conference – the early-bird rate closes July 14. Need ideas on how to secure funding for your participation? Visit our website for suggestions, a budget planning tool, and downloadable justification letter to share with your admin. Want to take advantage of the early rate – but know your district will pay eventually? Register online today and CSTA will reimburse you when we receive payment from your district/employer. (For more information on how that works contact Zi Stair in the office for details – 916-979-7004 or

New Information Now Available On-line:

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Goodbye Outgoing and Welcome Incoming CSTA Board Members

Posted: Wednesday, July 12th, 2017

Jill Grace

Jill Grace, CSTA President, 2017-2019

On July 1, 2017 five CSTA members concluded their service and four new board members joined the ranks of the CSTA Board of Directors. CSTA is so grateful for all the volunteer board of directors who contribute hours upon hours of time and energy to advance the work of the association. At the June 3 board meeting, CSTA was able to say goodbye to the outgoing board members and welcome the incoming members.

This new year also brings with it a new president for CSTA. As of July 1, 2017 Jill Grace is the president of the California Science Teachers Association. Jill is a graduate of California State University, Long Beach, a former middle school science teacher, and is currently a Regional Director with the K-12 Alliance @ WestEd where she works with California NGSS K-8 Early Implementation Initiative districts and charter networks in the San Diego area.

Outgoing Board Members

  • Laura Henriques (President-Elect: 2011 – 2013, President: 2013 – 2015, Past President: 2015 – 2017)
  • Valerie Joyner (Region 1 Director: 2009 – 2013, Primary Director: 2013 – 2017)
  • Mary Whaley (Informal Science Education Director: 2013 – 2017)
  • Sue Campbell (Middle School/Jr. High Director: 2015 – 2017)
  • Marcus Tessier (2-Year College Director: 2015 – 2017)

Learn More…

Written by California Science Teachers Association

California Science Teachers Association

CSTA represents science educators statewide—in every science discipline at every grade level, Kindergarten through University.

Finding My Student’s Motivation of Learning Through Engineering Tasks

Posted: Wednesday, July 12th, 2017

by Huda Ali Gubary and Susheela Nath

It’s 8:02 and the bell rings. My students’ walk in and pick up an entry ticket based on yesterday’s lesson and homework. My countdown starts for students to begin…3, 2, 1. Ten students are on task and diligently completing the work, twenty are off task with behaviors ranging from talking up a storm with their neighbors to silently staring off into space. This was the start of my classes, more often than not. My students rarely showed the enthusiasm for a class that I had eagerly prepared for. I spent so much time searching for ways to get my students excited about the concepts they were learning. I wanted them to feel a connection to the lessons and come into my class motivated about what they were going to learn next. I would ask myself how I could make my class memorable where the kids were in the driver’s seat of learning. Incorporating engineering made this possible. Learn More…

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Written by NGSS Early Implementer

NGSS Early Implementer

In 2015 CSTA began to publish a series of articles written by teachers participating in the California NGSS k-8 Early Implementation Initiative. This article was written by an educator(s) participating in the initiative. CSTA thanks them for their contributions and for sharing their experience with the science teaching community.

State Schools Chief Tom Torlakson Unveils Updated Recommended Literature List

Posted: Wednesday, July 12th, 2017

SACRAMENTO—State Superintendent of Public Instruction Tom Torlakson unveiled an addition of 285 award-winning titles to the Recommended Literature: Prekindergarten Through Grade Twelve list.

“The books our students read help broaden their perspectives, enhance their knowledge, and fire their imaginations,” Torlakson said. “The addition of these award-winning titles represents the state’s continued commitment to the interests and engagement of California’s young readers.”

The Recommended Literature: Prekindergarten Through Grade Twelve list is a collection of more than 8,000 titles of recommended reading for children and adolescents. Reflecting contemporary and classic titles, including California authors, this online list provides an exciting range of literature that students should be reading at school and for pleasure. Works include fiction, nonfiction, poetry, and drama to provide for a variety of tastes, interests, and abilities. Learn More…

Written by Guest Contributor

From time to time CSTA receives contributions from guest contributors. The opinions and views expressed by these contributors are not necessarily those of CSTA. By publishing these articles CSTA does not make any endorsements or statements of support of the author or their contribution, either explicit or implicit. All links to outside sources are subject to CSTA’s Disclaimer Policy:

Teaching Science in the Time of Alternative Facts – Why NGSS Can Help (somewhat)

Posted: Wednesday, July 12th, 2017

by Peter A’Hearn

The father of one of my students gave me a book: In the Beginning: Compelling Evidence for Creation and the Flood by Walt Brown, Ph. D. He had heard that I was teaching Plate Tectonics and wanted me to consider another perspective. The book offered the idea that the evidence for plate tectonics could be better understood if we considered the idea that beneath the continent of Pangaea was a huge underground layer of water that suddenly burst forth from a rift between the now continents of Africa and South America. The waters shot up and the continents hydroplaned apart on the water layer to their current positions. The force of the movement pushed up great mountain ranges which are still settling to this day, resulting in earthquakes along the margins of continents. This had happened about 6,000 years ago and created a great worldwide flood. Learn More…

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Written by Peter AHearn

Peter AHearn

Peter A’Hearn is the Region 4 Director for CSTA.