Ready, Set, Reaction!

Ready, Set, Reaction!

Experiment
More endothermic excitement coming your way!

Overview

Grades:
Time:
Subject:

5-8
20-30 minutes
Chemistry

Stirring up more reaction action as we further investigate the base + acid reaction discovered in PDQ 1.  Prepare to don your lab coat and do some serious science.  Let’s go!

Background

Welcome to more endothermic explorations!  Quiz time – what does the X-51A Waverider experimental US Air Force hypersonic aircraft have in common with a frying egg?  Both are reliant on endothermic reactions!  The reason your egg “cooks” is because it is absorbing heat energy from the pan which causes a chemical reaction. The X-51A flies at speeds in excess of 3,000 miles per hour which generates enormous heat. Engineers and scientists developed a special hyrdrocarbon fuel that actually absorbs heat and helps to cool systems in the aircraft so it can achieve these extraordinary speeds.

The amazing X-51A  uses a special endothermic fuel to stay cool!

A frying egg is great example of an endothermic reaction in action!

In this experiment we go further and change things up by changing the ratio of the reactants to get more and bigger fizz!   

  • Do you think the drop in temperature will remain the same or change as we change the mixture? 
  • Do you think you can master the experiment and control the temperature drop or CO2 production? 

Grab your databot™, and let’s find out!

Objectives

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

  • A physical change does not change the composition of a substance, only its form (state of matter).
  • 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.
    • Heavier than air
    • Exhaled by human beings.
    • Levels can vary in the air around us depending on many factors.
    • 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. 
  • A ratio is a numeric comparison of one amount to another. A percentage is a ratio based on a scale of 100.
  • 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
  • Optional: Computer with spreadsheet software (Excel, Sheets, Numbers, etc.) for doing additional data analysis.  
  • White Vinegar (acetic acid)
  • Baking Soda (sodium bicarbonate)
  • Container with an airtight lid.
    In the activity demonstrations, we are using an OXO brand, 4.2 liters,
    the storage container that has a push-button airlock feature. 
  • Measuring cups, spoons, or graduated cylinder for measuring quantities.
  • Glassware – low profile drinking glass or beaker for the reactants that will fit within your airtight container along with databot™. 

The glassware used in our demonstration to contain the reaction is a 250 ml beaker and this is adequate for the reaction. Study the video to better understand what you will need.

Important Terms

Acid: A substance that has a pH level of less than 7, can donate a hydrogen ion, and is characterized by a sour taste or smell.  If you have tasted pickle juice or smelled vinegar – those are both great examples of acids.

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.

Baking Soda, sodium bicarbonate (NaHCO₃):  An alkaline salt and is one of the reactants in the vinegar-baking soda reaction.

Base: A substance that has a pH level of higher than 7 and can accept a donated hydrogen ion from an acid.  A base is essentially an acid‘s opposite so when they get together some spectacular things can happen. Sodium bicarbonate (baking soda) is a good example of a base.  

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.

Density: An object’s mass in a given volume. For example, a 1 cm cube of gold is much denser than a 1 cm cube of balsa wood so the weight of the gold cube is much, much heavier.

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.    

Mass: The amount of matter in a substance.

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.

pH: A scale from 1-14 used to rate substances as either “acid” or “base” – the lower the number, the more acidic the substance.  Pure water has a pH of 7.

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.

Percentage: A proportion of one number compared to another and is based on a scale of 100.  If you have 30 white rocks in a pile of 100 pebbles, you have 30% white rocks!

Ratio: A numeric comparison of one item to another. For example, if you have 3 white rocks and 2 black rocks, the ratio is 3 to 2 and is written as 3:2.

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

Sodium Acetate (C2H3NaO2): One of the products of the vinegar-baking soda reaction comprised of carbon, hydrogen, oxygen, and sodium.

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).

Vinegar: a mixture of acetic acid (CH₃COOH) and water (H20) that is one of the reactants in the baking-soda vinegar reaction.

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.

Weight: A measurement of the force of gravity applied to an object – it is calculated by multiplying an object’s mass by the acceleration of gravity. The weight of an object can vary depending on the gravitational field it is in.

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.”  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 in your exhaled breath and the temperature should increase from your body heat. 
  • Organize your reactants and materials for quick and easy access.
  • Be aware that you don’t want to accidentally combine your reactants before you are ready, so keep the baking soda (sodium bicarbonate) and vinegar (acetic acid) separate! 
  • Be tidy and keep your workspace clean.

Experiment (15-25 Mins)

Step 1: Set up your “experiment chamber” as you did for PDQ1. You need an airtight container that has a known volume that will capture the CO2 gas produced by the reaction.  Materials:

  • Airtight container large enough to hold everything (shown here is a 4.2 liter OXO push-top sealing storage container).
  • Small glass beaker or drinking glass for the reaction to take place in.  You will be working with small quantities of reactants, but you don’t want it to overflow and soak databot™ so test your reactants in your glassware before doing the experiment in the chamber.
  • databot™ and temperature probe.  Place the temperature probe flat on the bottom of your glassware so it will be covered by the reaction.
  • Just as you did for PDQ 1, carefully measure and prepare your reactants for the experiment as detailed in the chart below.  Have your smart device with Phyphox pre-loaded with the experiment that records CO2 and Temperature.  This should be tested and ready to go as part of your preparation.

Step 2: Time to experiment!  You will be doing this experiment three times, each time using a different ratio of reactants.  Let’s go!

  • Turn on your databot™ and connect to  Phyphox using the CO2 + Temperature Probe experiment.
  • Begin recording and write down the starting temperature and CO2 reading in the table below.  
  • Have your chamber lid available as you will want to move quickly to seal the chamber!
  • Ready, set, and add the vinegar (acetic acid) to your reactant glassware.  Seal the chamber and watch the data as the reaction takes place!  Run the experiment for 3 minutes.
  • Reset your chamber (clean the glassware and probe thoroughly) and repeat the experiment twice more increasing the acid reactant each time according to the table. 

Reaction with a 6:1 ratio of reactants!  Shown here is the reaction using 30 ml of vinegar (acetic acid) and 5 ml of baking soda (sodium bicarbonate).  This is being conducted using a 250 ml beaker and we are getting close to overflow!!  Make sure your glassware is the right size so you don’t overflow and soak databot™!

Things to observe! 

  • The pressure generated by the production of CO2 increases with the volume of the gas produced.  In our 6:1 ratio video, you will notice that our chamber is reaching its pressure limit and the top is nearly coming off!!
  • databot’s™  CO2 sensor reads between 400 PPM and has a top reading level of 60,000 PPM.  In the reaction shown here, we max out the sensor.   Is the result of a hazardous environment to humans if you were inside a room with this level of CO2?   

 Analysis

Complete this study by doing the math extensions using the worksheet. Note the two extra columns for ratios and percentages.

  • What is the Acid to Base Ratio in each data run? A ratio is a comparison of two numbers.  For example, if you have 15 stones and 10 of them are black and 5 of them white, your ratio is 10:5 which can be reduced to 2:1.
  • What is the % CO2 level in your chamber?  Think about how you would convert Parts Per Million (PPM) to a %.  
  • Do you see any pattern in your data?
  • Could you predict a CO2 level based on your data?

Go Further

  • Export your experimental data from Phyphox at the end of each test run and load it into a spreadsheet program.  Using Excel, Google Sheets, or Apple Numbers you can  create some dazzling data displays that show your work.  Use your display to clearly explain your findings to someone. See an example below. Good luck and have fun! 

You’ve mastered some great challenges in this module.

Great job! Now for a new kind of adventure, prepare to be challenged to demonstrate your new-found knowledge and skills. Good luck!

Next Step, Challenge!

Go!

Educator Info

Educator Info

  • Study the background information in the Overview and familiarize yourself with the learning objectives and terms for this activity.
  • Set-up and test the experiment and practice it yourself before conducting it with your class.
  • Review the guiding questions to help guide the student experience.
  •   If students are conducting the experiment make sure the glassware is of adequate size to contain the reactions. 
    You don’t want to soak your databot™!
  • Fill out the data collection sheet and perform the calculations so you are prepared.  You can calculate the % of CO2 in your container by dividing the reading by 1,000,000 as it is reading “parts per million.”
  • Attempt the challenge – it is not easy! Can you stir up a reaction that results in an exact 3% CO2 environment.
  • Plan for disposal of the liquid product in a tidy fashion.

Understand and Recognize:

  • A physical change does not change the composition of a substance, only its form (state of matter).
  • 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.
    • Heavier than air
    • Exhaled by human beings.
    • Levels can vary in the air around us depending on many factors.
    • 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. 
  • A ratio is a numeric comparison of one amount to another. A percentage is a ratio based on a scale of 100.
  • 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.
  • 5-PS1-4: Conduct an investigation to determine whether the mixing of two or more substances results in new substances.
  • 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.
  • MS-PS1-6: Undertake a design project to construct, test, and modify a device that either releases or absorbs thermal energy by chemical processes. Emphasis is on the design, controlling the transfer of energy to the environment, and modification of a device using factors such as type and concentration of a substance. Examples of designs could involve chemical reactions such as dissolving ammonium chloride or calcium chloride. Assessment is limited to the criteria of amount, time, and temperature of substance in testing the device.
  • 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.

The following questions may or may not be appropriate for the age group you are working with so use your discretion.

  • What are the states of matter?
  • What states of matter do we see in our experiment here?
  • What are the reactants in our experiment?
  • What is the product?
  • Is this a physical change or a chemical change?
  • Does it appear we have created new substances in our experiment?  
  • How could we get our baking soda and vinegar back to normal?
  • Do you suppose this experiment could be dangerous if we were careless?  How?
  • Does the temperature change in this reaction? Why?
  • The products shown in the diagram are water, sodium acetate, and CO2.   Which of these can you only see with databot™?

How should the reaction between vinegar and baking soda be classified?
https://antoine.frostburg.edu/chem/senese/101/reactions/faq/classify-vinegar-bakingsoda.shtml

Misconceptions about science
http://modeling.asu.edu/modeling/KindVanessaBarkerchem.pdf

Why Does Vinegar and Baking Soda React?

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.