Ready, Set, Reaction!

Ready, Set, Reaction!

PDQ2
Water from air? Abracadabra!

Overview

Grades:
Time:
Subject:

5-8
5-15 minutes
Chemistry

Kaboom – it’s the 4th of July!  Whether you’re watching fabulous fireworks or lighting a candle you’re watching a chemical reaction take place.  This PDQ will fire up your scientific skills and introduce you to the science of burning candles.  Let’s explore!

Background

Chemical reactions take place around us all the time whether it is a car’s engine burning gasoline, your stomach digesting, or someone cooking dinner.   The magic of chemistry creates new substances that didn’t exist when these reactions take place.  Sometimes it’s a good thing and sometimes not so good if we think about pollution from internal combustion engines.

How all of this happens takes place at a microscopic level that we can’t see.  All matter is made up of tiny particles called atoms and molecules and, at an even smaller level, atoms and molecules are made up of particles also!  These sub-atomic particles – protons, neutrons, and electrons – have the ability to travel and exchange in certain circumstances and when they do, like magic, you have a new substance!

In this PDQ databot™ enters an airtight chamber with a burning candle to explore what’s going on in this unique chemical reaction.  Every time you light a match or burn a candle you are engaging with a chemical reaction that creates new substances!  The following diagram shows what a burning candle chemical reaction looks like.  The paraffin wax of a typical candle is known as a hydrocarbon – it has a long chain of carbon atoms and hydrogen atoms are connected to it.   The particles transform into new substances when fire – “combustion” -takes place!  

Look closely at the equation and at the products of the reaction.  Did you know that water (H2O) is being created when you burn a candle? By placing databot™ in an airtight chamber with a burning candle we will be able to contain these products and confirm this reaction using scientific sensors!  

Ready to get started?  Let’s fire this activity up and get going!

Objectives

By completing this experiment and conducting the scientific observations associated with it you will master the following knowledge! Good luck science explorer!

  • Different types of substances can “react” with one another to create a chemical change in the substances.
  • Chemical Reaction:
    • When two substances react with one another to create a new, different substance.
    • Causes a change in the composition of a substance.
    • Can cause physical and chemical changes in substances – even creating gas where there was none before.
    • Can require energy (endothermic) to take place or produce energy (exothermic).
  • CO2:
    • An invisible and odorless gas.
    • Exhaled by human beings.
    • Can be generated through a chemical reaction of baking soda and vinegar.
  • The pH scale tells us if a substance is a base or an acid.   
  • Vinegar (acetic acid) is an acid and baking soda (sodium bicarbonate) is a base. 
  • Scientific sensors allow us to measure the scientific world around us with better precision and accuracy.

What You'll Need

  • IOS or Android smart device with Bluetooth Low Energy (BLE) to connect to databot™
  • databot™ + Phypox App installed on your IOS or Android device
  • databot™ Temperature Probe
  • Container with an airtight lid.
    In the activity demonstrations, we are using an OXO brand, 4.2 liters, storage container that has a push-button airlock feature. 
  • Tea candles – 1
  • Lighter (Long-Handled)

Important Terms

Atom: The basic unit of matter and is the smallest thing that can have a chemical property.  Hydrogen and Carbon are both examples of atoms.

Carbon Dioxide (CO2): A colorless, odorless gas naturally present in the air you breathe and is absorbed by plants in photosynthesis. There would be no animal life or green plants without carbon dioxide. Green plants use energy from the sun plus carbon dioxide and water to produce carbohydrates and oxygen. CO2 is one of the products of the vinegar-baking soda reaction comprised of 1 carbon atom and 2 oxygen atoms.

Chemical Reaction: When substances combine to produce one or more new substances.

Endothermic Reaction: A type of chemical reaction that requires energy to take place.  When this happens you will see a drop in temperature in your reactants.  

Exothermic Reaction: A type of chemical reaction that produces energy.  When this happens you will see an increase in temperature.    

Humidity: The percentage of water vapor in the air you breathe. You will notice humidity changes when you travel – for example, in the desert there is very low humidity and by the sea, you will have high levels of humidity.

Molecule: Made up of atoms and is the smallest amount of a chemical substance that still retains all the characteristics of that substance. A good example of a molecule is water. Represented as H2O, it has 2 hydrogen atoms and one oxygen atom.

Physical Reactions: When a substance changes form, but not its composition.  For example, water turning from liquid form to ice.  It’s still water, just in a different state.

Product: The substance created in a chemical reaction.

Reactant: The starting substance that enters into a chemical reaction.

States of Matter: The 4 states a substance can take on:  solid, liquid, gas, or plasma.

Temperature: A measure of a physical property of a substance – how hot or cold is it? Temperature is actually a measure of moving particles in a substance and is expressed in different units such as degrees Celsius.

Units of Measure (metric): Liters, milliliters, parts per million (PPM).

Volume: The amount of space a substance takes up.

Water (H20): A product of the vinegar-baking soda reaction comprised of 2 hydrogen atoms and one oxygen atom. It is also a product of the chemical reaction that takes place when you burn a candle.

Prep (5 Mins)

  • Fully charge your databot™, plug in your temperature probe, and test your connection to Phyphox.
  • Load the correct experiment from your Phyphox CO2 collection on your app labeled “CO2 + Temp + RH.”  Do a quick test by connecting to databot™ and starting the data recording. 

Now breathe on databot™and hold the temperature probe tightly to collect data and make sure everything is working properly! It should display CO2 and water vapor in your exhaled breath and the temperature should increase from your body heat. 

  • Organize your materials for quick and easy access. 
  • Have supervision and permission for lighting candles and working with fire!
  • Be tidy and keep your workspace clean.

PDQ Instructions (5 mins)

Step 1:  Let’s setup!

  • Prepare the testing chamber as shown here with your databot™ and temperature probe on one side of the chamber and the candle on the opposite side.
  • Notice how the temperature probe is propped up to keep it elevated.   Be careful that it is stable and won’t fall into the flame.
  • Practice putting the top on your container and sealing it so you can do it smoothly when you begin your experiment.

Step 2: Time to experiment!

  • Turn on your databot™i n the chamber.
  • Select the CO2 + Temp + RH sensor combination in Phyphox.
  • Connect to databot™ with Bluetooth and begin recording. 
  • Write down the starting levels for CO2, Temperature, and Humidity (RH). 
  • Light the candle and quickly seal the chamber.
  • Watch the data as the candle burns.  The candle will use up some of the oxygen in the chamber and go out after a minute or two. 
  • Stop the recording when the candle goes out.
  • Write down the end levels from your data recording.

Observations and Deep Thoughts!

Calculate the net change recorded during the experiment for each variable.

  • What happens to the temperature during the reaction?
  • What happens to CO2 levels during the reaction?
  • Is this chemical reaction endothermic or exothermic?
  • Humidity is a reading of water vapor in the air – H2O.  Did it increase or decrease?
  • Look at the chemical reaction formula again. What are the products that should have resulted?  Does the data confirm that this chemical reaction took place?

Wow, you came off the blocks like a rocket!

Since you came off the blocks like a rocket in PDQ 1 and 2, are you ready for a bigger bite? Next stop, the Experiment!

Next Step, Time to Experiment!

Go!

Educator Info

Educator Info

This PDQ is a very simple activity to set up and perform.  Conduct the experiment several times yourself to familiarize yourself with doing it smoothly and quickly.

  • Review the Important Terms and Objectives.  
  • Make sure you have added the databot™ CO2 Science experiment collection into Phyphox using the provided QR code.
  • Fully charge your databot™, plug in your temperature probe, and test your connection to Phyphox.
  • Load the correct experiment from your Phyphox CO2 collection on your app labeled “CO2 + Temp + RH.”  Do a quick test by connecting to databot™ and starting the data recording. 

Now breathe on databot™ and hold the temperature probe tightly to collect data and make sure everything is working properly! It should display CO2 and water vapor in your exhaled breath and the temperature should increase from your body heat. 

  • Review the Challenge from this module to see how this activity can be extended upon.

This activity can be adjusted based on age groups and your desired experience.  For younger students, you may simply want to introduce the concepts of chemical reactions and demonstrate an exothermic reaction.  Older students have many opportunities to go much deeper with additional connections.  This activity is extended in this module’s Challenge as well which provides additional opportunities for deeper learning.

  • Different types of substances can “react” with one another to create a chemical change in the substances.
  • Chemical Reaction:
    • When two substances react with one another to create a new, different substance.
    • Causes a change in the composition of a substance.
    • Can cause physical and chemical changes in substances – even creating gas where there was none before.
    • Can require energy (endothermic) to take place or produce energy (exothermic).
  • CO2:
    • An invisible and odorless gas.
    • Exhaled by human beings.
    • Can be generated through a chemical reaction of baking soda and vinegar.
  • The pH scale tells us if a substance is a base or an acid.   
  • Vinegar (acetic acid) is an acid and baking soda (sodium bicarbonate) is a base. 
  • Scientific sensors allow us to measure the scientific world around us with better precision and accuracy.
  • 5-PS1-1: Develop a model to describe that matter is made of particles too small to be seen.
  • MS-PS1-2: Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
  • NGSS Practice 4: Analyzing and Interpreting Data
    Excerpt: When possible and feasible, students should use digital tools to analyze and interpret data. Whether analyzing data for the purpose of science or engineering, it is important students present data as evidence to support their conclusion.

This article is a deep treatment of student misconceptions related to fire.

Exploring Secondary Students’ Conceptions about Fire Using a Two-Tier,
True/False, Easy-to-Use Diagnostic Test
Patrice Potvin, Yannick Skelling-Desmeules, Ousmane Sy
Université du Québec à 

A few examples from this paper:

  • Smoke and Ash are the only products of fire.
  • The candle wick is the fuel for the fire.
  • Oxygen is not required for fire.
  • The candle wax is not burning, it is simply melting.

David Rudel’s Science Myths Unmasked is an excellent source of additional information:  the burning candle does not use up all of the oxygen in the jar, only about 30% of it.

  • What is the physical change taking place with the burning candle?
  • Why does the candle go out?
  • What are the reactants in this chemical reaction?
  • What are the products?

Awesome and simple to follow information on the science of candles from the National Candle Association.

Highly recommended reading is Chapter 2 from David Rudel’s Science Myths Unmasked which addresses misconceptions about the candle in a jar experiment.

Incredible Caffeine Molecule image by Michael Ströck. Thank you!!

Candle image by Michael Schwarzenberger on Pixabay. Awesome!

 

Ready, Set, Reaction! by Robert O. Grover & Team databot™ is licensed under a Creative Commons Attribution 4.0 International License. Permissions beyond the scope of this license may be available at databot.us.com/contact.