January/February 2018 – Vol. 31 No. 2

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

Leave a Reply


Accelerating into NGSS – A Statewide Rollout Series Now Accepting Registrations

Posted: Friday, January 19th, 2018

Are you feeling behind on the implementation of NGSS? Then Accelerating into NGSS – the Statewide Rollout event – is right for you!

If you have not experienced Phases 1-4 of the Statewide Rollout, or are feeling behind with the implementation of NGSS, the Accelerating Into NGSS Statewide Rollout will provide you with the greatest hits from Phases 1-4!

Accelerating Into NGSS Statewide Rollout is a two-day training geared toward grade K-12 academic coaches, administrators, curriculum leads, and teacher leaders. Check-in for the two-day rollout begins at 7:30 a.m., followed by a continental breakfast. Sessions run from 8:00 a.m. to 4:15 p.m. on Day One and from 8:00 a.m. to 3:30 p.m. on Day Two.

Cost of training is $250 per attendee. Fee includes all materials, continental breakfast, and lunch on both days. It is recommended that districts send teams of four to six, which include at least one administrator. Payment can be made by check or credit card. If paying by check, registration is NOT complete until payment has been received. All payments must be received prior to the Rollout location date you are attending. Paying by credit card secures your seat at time of registration. No purchase orders accepted. No participant cancellation refunds.

For questions or more information, please contact Amy Kennedy at akennedy@sjcoe.net or (209) 468-9027.



MARCH 28-29, 2018
Host: San Mateo County Office of Education
Location: San Mateo County Office of Education, Redwood City

APRIL 10-11, 2018
Host: Orange County Office of Education
Location: Brandman University, Irvine

MAY 1-2, 2018
Host: Tulare County Office of Education
Location: Tulare County Office of Education, Visalia

MAY 3-4, 2018
Host: San Bernardino Superintendent of Schools
Location: West End Educational Service Center, Rancho Cucamonga

MAY 7-8, 2018
Host: Sacramento County Office of Education
Location: Sacramento County Office of Education Conference Center and David P. Meaney Education Center, Mather

JUNE 14-15, 2018
Host: Imperial County Office of Education
Location: Imperial Valley College, Imperial

Presented by the California Department of Education, California County Superintendents Educational Services Association/County Offices of Education, K-12 Alliance @WestEd, California Science Project, and the California Science Teachers Association.

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.

The Teaching and Learning Collaborative, Reflections from an Administrator

Posted: Friday, January 19th, 2018

by Kelly Patchen

My name is Mrs. Kelly Patchen, and I am proud to be an elementary assistant principal working in the Tracy Unified School District (TUSD) at Louis Bohn and McKinley Elementary Schools. Each of the schools I support are Title I K-5 schools with about 450 students, a diverse student population, a high percentage of English Language Learners, and students living in poverty. We’re also lucky to be part of the CA NGSS K-8 Early Implementation Initiative with the K-12 Alliance. Learn More…

Powered By DT Author Box

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.

2018 CSTA Conference Call for Proposals

Posted: Wednesday, January 17th, 2018

CSTA is pleased to announce that we are now accepting proposals for 90-minute workshops and three- and six-hour short courses for the 2018 California Science Education Conference. Workshops and short courses make up the bulk of the content and professional learning opportunities available at the conference. In recognition of their contribution, members who present a workshop or short course receive 50% off of their registration fees. Click for more information regarding proposals, or submit one today by following the links below.

Short Course Proposal

Workshop Proposal 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.

CSTA’s New Administrator Facebook Group Page

Posted: Monday, January 15th, 2018

by Holly Steele

The California Science Teachers Association’s mission is to promote high-quality science education, and one of the best practice’s we use to fulfill that mission is through the use of our Facebook group pages. CSTA hosts several closed and moderated Facebook group pages for specific grade levels, (Elementary, Middle, and High School), pages for district coaches and science education faculty, and the official CSTA Facebook page. These pages serve as an online resource for teachers and coaches to exchange teaching methods, materials, staying update on science events in California and asking questions. CSTA is happy to announce the creation of a 6th group page called, California Administrators Supporting Science. 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: http://www.classroomscience.org/disclaimer.

Find Your Reason to Engage

Posted: Monday, January 15th, 2018

by Jill Grace

I was recently reflecting on events in the news and remembered that several years ago, National Public Radio had a story about a man named Stéphane Hessel, a World War II French resistance fighter, Nazi concentration camp survivor, and contributor to the United Nation’s Universal Declaration of Human Rights. The story focused on a book he had published, Time for Outrage (2010).

In it, Hessel makes the argument that the worst attitude is indifference:

“Who is in charge; who are the decision makers? It’s not always easy to discern. We’re not dealing with a small elite anymore, whose actions we can clearly identify. We are dealing with a vast, interdependent world that is interconnected in unprecedented ways. But there are unbearable things all around us. You have to look for them; search carefully. Open your eyes and you will see. This is what I tell young people: If you spend a little time searching, you will find your reasons to engage. The worst attitude is indifference. ‘There’s nothing I can do; I get by’ – adopting this mindset will deprive you of one of the fundamental qualities of being human: outrage.  Our capacity for protest is indispensable, as is our freedom to engage.”

His words make me take pause when I think of the status of science in the United States. A general “mistrust” of science is increasingly pervasive, as outlined in a New Yorker article from the summer of 2016. Learn More…

Powered By DT Author Box

Written by Jill Grace

Jill Grace

Jill Grace is a Regional Director for the K-12 Alliance and is President of CSTA.