Stoichiometry Fireworks Lab Quiz

Ignition of sugar and potassium chlorate produces purple flames and sparks.

Given the amount of one reactant, students must use stoichiometry to find the ideal amount of the second reagent to use to create purple fireworks. The teacher ignites each groups' fireworks. Ideal mixture create little or no ash. Student assignment sheet with directions (and different initial amounts) plus teacher information and sample answers are included. This is an exciting and engaging activity that can be used as a stoichiometry quiz.

These worksheets are part of a entire unit on teaching stoichiometry. You can access the complete lesson plans with information on their use, and links to other worksheets, labs, and activities at  http://www.jce.divched.org/article/stoichiometry-easy

Concepts: 

Stoichiometry, limiting reactant, laboratory measures

Time required: 

With one balance per table (two groups), the calculations should take about 10 minutes, the measures another 10 minutes. Ideally, students should be prepared to deliver their mixture to the teacher within 20 minutes. In practice, many students will take longer, particularly if the formula for potassium chlorate is not given and students are not familiar enough with ionic nomenclature.

The teacher will need about one minute per group to announce the group's mixture, ignite it, and wait for student responses. So if there are 15 groups, the teacher should allow about 15 minutes to ignite all the mixtures.

Materials: 

Student materials:

  • 1 - 100 mL beaker       
  • 1 - 250 mL beaker
  • Vial of potassium chlorate (KClO3)
  • Vial of sugar (C12H22O11)
  • Stirring rod
  • Wax pencil
  • Centigram balance (ideally one for each lab table).
  • goggles

Teacher Materials:   

  • Fireproof board       
  • Bunsen burner (with long hose)
Background: 

This experiment is best done in groups of two. Students should have learned how to do stoichiometry problems, be experienced in using a balance, and be able to follow basic directions.

For this lab quiz students are given a specified amount of one reactant (the limiting reactant), and must complete the correct stoichiometry calculation to determine the ideal amount of the other reactant. They are instructed to show all their work.

 

In a fume hood, the teacher ignites each groups' mixture. Ideally, there are purple flames and sparks and very little white "ash." An excess of sugar results in production of carbon "worms." And excess of potassium chlorate does not burn well and is difficult to ignite.

Procedure: 

See the student lab sheet.

Questions: 

See the student lab sheet.

Preparation: 

Each table (two groups) needs one balance and one vial of each reagent plus a 100 mL and a 250 mL beaker for each group (two of each beaker). It is convenient to have all the student materials placed in a tub or basket. Each table also should have a centigram balance, if possible. If more than two groups must share a balance, the lab quiz may take more time than is available.

Credits: 
Mr. Courtney Lantz, Pacifica High School, Garden Grove, CA (retired) contributed to the development of this lab experiment.
Attribution: 

David P. Licata, Pacifica High School, Garden Grove, CA (retired)

Join the conversation.

Comments 14

Doug Ragan's picture
Doug Ragan | Wed, 11/05/2014 - 14:27

I am interested in the lab but I can't get the links to upload the pdf document.  Can you please resubmit both teacher and student document.  Thanks.

DAVID LICATA's picture
DAVID LICATA | Wed, 11/05/2014 - 16:04

Doug,

Thanks for the comment. I just checked (2 pm PDT) with my system (Firefox and Windows 7), and the PDF files came up promptly (well, once I remembered to login). I know that Jon and Deanna had a conversation this morning, possibly with some maintenance on the system. Perhaps try again? If you still do not get the file it may need an email to Jon Holmes.

ChemEd X Web Admin's picture
ChemEd X Web Admin | Wed, 11/05/2014 - 16:13

It looks as though Chrome is having problems with downloading the Student and Teacher documents. When I try to download either of these documents using a recent version of Chrome on OS X, it gets stuck with a 'Loading' message near the bottom of the window. Are you perhaps using Chrome on OS X?

Alternatively in Chrome, if you right-click the link and 'Save link as...', the file downloads and you can track it down in your downloads folder and open the file. You might try using another browser such as Firefox, Safari, or Internet Explorer on Windows 7 and 8. I have had success using all of these browsers.

I am attempting to troubleshoot this problem and arrive at a solution, which I will post here (if I find one).

Doug Ragan's picture
Doug Ragan | Thu, 11/06/2014 - 07:50

It was a chrome issue.  Safari cleared it up.  Thanks again for posting this activity.

Maria Kraakman ... | Fri, 11/07/2014 - 10:48

I was immediately thrilled about this Lab Quiz! I am going to do the quiz the last lesson before the Christmas Holidays. Thank you for sharing this!

Maria KraakmanChemistry teacherCartesius LyceumAmsterdam, The Netherlands

DAVID LICATA's picture
DAVID LICATA | Fri, 11/07/2014 - 18:49

Thanks for the kind comment.

Look for more items, including a specifically Christmas-themed (though algorithmic) aid to learning how to do stoichiometry. Not sure how it will translate into Norwegian, but perhaps your own creativity will find a way to make it work. I am slowly getting my entire stoichiometry unit of worksheets, labs (which are done), collaborative activities, and the Christmas-themed aid uploaded. I am working with the ChemEdX staff to get through some issues with uploading, formatting, and so on, so the work is going slowly. Eventually everything will be linked to a single article that describes the lesson plans I used for nearly 30 years. I hope you will enjoy them.

I hope that you and your students will have fun with this activity. I always promote it several days in advance by telling students that those who do the best will end up with only a small amount of salt, but those who do poorly will be obvious due to the "big ash-sh-sh-sh-sh-huh" that they have -- this takes advantage of the close correspondence in sound between the English word "ash" and the English word for a person's back side. Of course it generates smiles and a few snickers -- and a few more when students see a group that does leave a lot of burnt sugar ash. Again, not sure how that will translate, but we have fun with it.

Marten Lettinga | Sat, 11/08/2014 - 13:20

This excercise would also be good practice for students to balance redox reactions based on the change in oxidation numbers of C and Cl. On another note, this mixture can also be self-ignited with a small amount of concentrated sulfuric acid but that would undoubtedly also produce some carbonaceous by-product due to the exothermic decomposition of some of the sugar (like in the carbon sausage demo). I wonder if that variation would give similar results (i.e. very little ash except for a tiny bit of carbonaceous by-product produced).

Caroline Lehman's picture
Caroline Lehman | Mon, 11/10/2014 - 09:34

Thank you so much.  A good idea which looks like fun and I look forward to using it soon!  

Caroline Lehman

Jaymee Jenkins's picture
Jaymee Jenkins | Wed, 11/19/2014 - 12:04

Thank you so much for your great ideas. I have been teaching for a long while, but am always looking for ideas and ways to improve. As soon as I get a free minute (Christmas break?), I am going to take a closer look at this.

DAVID LICATA's picture
DAVID LICATA | Wed, 11/19/2014 - 19:39

Thanks for the comment. I am sure your students will find the lab fun, and the "competition" exciting. Let me suggest that you take a look at the lab, and my article on how I taught stoichiometry during your Thanksgiving break (well, if you are in the US -- other than turkey and football, you won't have anything else to do, will you??).

The entire article and links to all the other materials I used is at:

http://www.jce.divched.org/article/stoichiometry-easy

You will find more items there, some that you might want to start using before Christmas.

D.

Yvette Masullo's picture
Yvette Masullo | Sun, 11/23/2014 - 10:21

This doesn't seem to work...advice?

These worksheets are part of a entire unit on teaching stoichiometry. You can access the complete lesson plans with information on their use, and links to other worksheets, labs, and activities at http://www.jce.divched.org/article/stoichiometry-easy

Yvette Masullo

Chemistry teacher

ChemEd X Web Admin's picture
ChemEd X Web Admin | Mon, 11/24/2014 - 20:52

I have corrected the bad link. Thanks for letting us know.

Deanna Cullen's picture
Deanna Cullen | Mon, 11/24/2014 - 15:03

If you are having trouble opening the link, try opening the links using Safari. We are working on a better solution, but hopefully this will help until then.

Thanks! 

Deanna

DAVID LICATA's picture
DAVID LICATA | Wed, 11/26/2014 - 16:04

There was a broken link caused by my error in cutting and pasting the URL. It is fixed now thanks for Jon Holmes. I hope you enjoy the article and the lab.