Dancing Popcorn (Stephanie Moore)

Title: "Dancing" Popcorn

Principle(s) Investigated:

Chemical reactions between a combination of substances and how that reaction impacts the matter (popcorn). Taking into account also aspects such as volume, density, solubility, viscosity, and the molecular force of various substances.

Combination # 1 - Vinegar and Baking Soda

Combination # 2 - Water and Baking Soda

Combination # 3 - Lemon Juice and Baking Soda

Combination # 4 - Vegetable Oil and Baking Soda

Combination # 5 - Vinegar and Alka-Seltzer

Combination # 6 - Water and Alka-Seltzer

Combination # 7 - Lemon Juice and Alka-Seltzer

Combination # 8 - Vegetable Oil and Alka-Seltzer

Standards:

• Disciplinary Core Ideas (DCI) - MS: PS1 - 2 Matter and its Interactions
  • Analyze and interpret data on the properties of substances before and after the substances interact to determine if a chemical reaction has occurred.
• Disciplinary Core Ideas (DCI) - MS: PS1 -2 Matter and its Interactions
  • Analyze data from tests of an object or tool to determine if it works as intended
• Disciplinary Core Ideas (DCI) - MS: PS1 - 4 Matter and Its Interactions
  • Gases and liquids are made of molecules or inert atoms that are moving about relative to each other.
• Science and Engineering Practices (SEP): Analyze and Interpreting Data
  • Analyzing data in 6-8 builds on K-5 and progresses to extending quantitative analysis to investigations, distinguishing between correlation and causation, and basic statistical techniques of data and error analysis.
• Science and Engineering Practices (SEP): Obtaining, Evaluating and Communication Information
  • Obtaining, evaluating, and communicating information in 6-8 builds on K-5 and progresses to evaluating the merit and validity of ideas and methods
• Cross Cutting Concepts (CCC): Patterns
  • Macroscopic patterns are related to the nature of microscopic and atomic-level structures
• Cross Cutting Concepts (CCC): Cause and Effect
  • Cause and effect relationships may be used to predict phenomena in natural or designed systems

Materials:

• 8 Mason Jars
• 8 Plastic Knives (to stir)
• 4 cups to hold reactant (1 Tbsp baking soda in EACH)
• 2 lbs of Popping Corn
• 1 lb of Baking Soda
• 24 fluid ounces of vegetable oil
• 24 fluid ounces of lemon juice
• 16 fluid ounces of white vinegar
• 4 Alka-Seltzer Tablets
• All of these supplies I purchased at Target except the mason jars and I got those at Michael's (they were on sale there).
• Having 8 combinations, I can have people pair up and have groups of 2 with each mason jar.
• There is about 16-20 people in our class.
  • If you have a class of 40 either you need groups of 4 or you need 20 of everything where I wrote 8.

Procedure:

On a Google Sheet with all student names on it. Have students answer these 2 questions before you start the experiment.

Predict: 1) What combination will produce the most actively "dancing" popcorn? 2) Why?

• In the 1st mason jar, add 1 cup of vinegar and enough popping corn kernels to fill the bottom of the jar (about 15-20).
• In the 2nd mason jar, add 1 cup of water and enough popping corn kernels to fill the bottom of the jar (about 15-20).
• In the 3rd mason jar, add 1 cup of lemon juice and enough popping corn kernels to fill the bottom of the jar (about 15-20).
• In the 4th mason jar, add 1 cup of vegetable oil and enough popping corn kernels to fill the bottom of the jar (about 15-20).
• Then add 1 Tablespoon of Baking Soda to EACH of the 4 mason jars.
• No need to stir any of these 4 mason jars.
• Record the results on the Google Sheet.
  • How many seconds did it take for a reaction take place?
  • Write down at least 2 observations.
  • If so, how long does the popcorn "dance" for?

Do the mason jars in stages, so that students can observe each others reactions.

• In the 5th mason jar, add 1 cup of vinegar and enough popping corn kernels to fill the bottom of the jar (about 15-20).
• In the 6th mason jar, add 1 cup of water and enough popping corn kernels to fill the bottom of the jar (about 15-20)
• In the 7th mason jar, add 1 cup of lemon juice and enough popping corn kernels to fill the bottom of the jar (about 15-20).
• In the 8th mason jar, add 1 cup of vegetable oil and enough popping corn kernels to fill the bottom of the jar (about 15-20).
• Then add 1 Alka-Seltzer Tablet to EACH of the 4 mason jars.
• STIR as needed!!!!
• Record the results on the Google Sheet.
  • How many seconds did it take for a reaction take place?
  • Write down at least 2 observations.
  • If so, how long does the popcorn "dance" for?
• Debrief the results WITH A PARTNER.
  • What observations did you write down?
  • Hypothesize: Why does the popcorn "dance"?
    • Think about volume, density of liquids, solubility, viscosity, and molecular forces of the liquids
    • What are the bubbles that form on the popcorn?
    • Why are they important?
  • Write responses on Google Sheets.
  • What observations did you write down? (Give a different one that your partner)
  • Hypothesize: Why does the popcorn "dance"?
  • Was the combo that you predict at the start correct?
  • Who cares? Why does this matter? (No pun indeed)
• Debrief responses AS A CLASS.
  • Observations
  • Hypothesize: Why does the popcorn "dance"?
    • Think about volume, density of liquids, solubility, viscosity, and molecular forces of the liquids
    • What are the bubbles that form on the popcorn?
    • Why are the bubbles important?
  • Who cares? Why does this matter? (No pun indeed)

Student prior knowledge:

Students need to understand that sometimes mixing chemicals causes reactions and sometimes it does not cause a reaction.

Example #1 - Have you ever seen rust on a car? Rust is a chemical reaction between iron and oxygen.

Example # 2 - Have you ever seen something on fire? Burning wood for example is a oxidation reduction reaction.

Example # 3 - Some reactions happen inside living things. Such as in plants photosynthesis or humans respiration or digestion. Humans don't explode breathing in air or breakdown their food. These chemical reactions are more subtle.

Some reactions are fast and some reactions are slow. Fast reactions tend to occur at a higher temperature while slower reactions tend to occur at a cooler temperature.

Explanation:

Before the baking soda was added to the mason jars # 1-4, nothing was happening. After the baking soda was added, you see a reaction taking place. Baking soda reacts quickly in the lemon juice and vinegar by bubbling up and foaming over the top of the mason jar. The water and baking soda is as obvious of a reaction and the vegetable oil, while the vegetable oil and baking soda show no reaction at all.

Before the Alka-Seltzer tablet was added to the mason jars #5-8, nothing was happening. After the Alka-Seltzer was added, the reaction in the vinegar, lemon juice, and water is pretty quick to start form bubbles around the popcorn. There is no reaction between the vegetable oil and the Alka-Seltzer. This is due to the fact that vegetable oil is not soluble and therefore does not breakdown the Alka-Seltzer tablet. Without the breakdown of the tablet, the reaction does not occur.

Most of the reactions cause the two substances to start a chemical reaction which forms millions of tiny particles to form on the popcorn. These particles are made of carbon dioxide, which is a gas. Eventually, the popcorn rises to the surface of the given liquid (vinegar, lemon juice, and water) because the gases are being trapped underneath the popcorn.

The particles stick to the popcorn and that is what pulls the popcorn to the surface. When the carbon dioxide bubbles pop, the popcorn falls back down to the bottom of the mason jar. Then the particles will start forming on the popcorn again and pull it back to the surface again. The the carbon dioxide gas bubbles will pop, releasing the gas into the air and the popcorn will sink back down to the bottom of the mason jar again. The popcorn sinks back down because after the gas is releasing the popcorn kernel is once again more dense than that of the water, lemon juice, or vinegar.

In the case of the vinegar and baking soda, when they mix, the react to each other and form sodium bicarbonate, and this sodium bicarbonate undergoes the chemical reaction, which changes to carbon dioxide, which is what causes the gas bubbles to form.

These carbon dioxide bubbles are less dense than the liquid that surrounds them, so they rise to the surface of the liquid that they are in. Less dense liquids and gases float above more dense liquids and gases.

Both baking soda and Alka-Seltzer are made of bases called bicarbonate. This bicarbonate undergoes a chemical reaction in all the substances except the vegetable oil, which changes the bicarbonate into carbon dioxide.

The two mason jars that contain vegetable oil are important to show that just because a reactant (baking soda or Alka-Seltzer) causes a reaction in one substance does not mean it causes a reaction in all substances.

Questions & Answers:

1. Predict which combination will cause the popcorn to actively "dance" the most?

Water and Alka-Seltzer - chemical reaction occurred more slowly because the Alka-Seltzer tablet had to dissolve first because the gas bubbles could begin to form on the popcorn to make it rise to the surface of the water

2. What makes the popcorn "dance"?

The release of carbon dioxide gas, when gas dissipates the popcorn falls back down to the bottom of the jar

3. Why did some reactions last longer than others? What factor(s) cause that?

Baking soda was a good reactant in both the lemon juice and vinegar. The baking soda caused a quick reaction much like a hot magma rising up from the ground and out of the top of the volcano.

The Alka-Seltzer tablet did not dissolve in the vegetable oil. Without the tablet dissolving, it doesn't release the carbon dioxide gas needed to start the popcorn "dancing".

Applications to Everyday Life:

• Climate change is caused by the build up if carbon dioxide in the atmosphere when it is released from wildfires, automobile exhaust, factories smokestacks
• Wildfires give off carbon dioxide gas - fires like this week (10/28/19 - Getty Fire) and last week (10/21/19 - Palisades Fire, Porter Ranch Fire, Tick Fire in Canyon Country)
• When humans exhale they expel carbon dioxide gas back into the air, which is why we need trees to take in this carbon dioxide, which is also why Arbor Day and Earth Day are important to raise awareness of the importance of trees to humans and the environment
• Carbon dioxide gas is used in extinguishing fires (fire extinguisher) because it does not burn and does not help in burning
• Carbon dioxide gas, ammonia, chlorofluorocarbons, sulfur dioxide are used for cooling in refrigerators and air conditioners
• Carbon dioxide gas is used in making soft drinks and beer - the hissing that you hear when you open a 2 liter of Coke
• Carbon dioxide gas is used in the food industry, the oil industry and the chemical industry and in many consumer products what require pressurized gas because it is inexpensive and nonflammable
• Carbon dioxide gas is used in baking, it causes bread and cookies to bubble - making them porous, light, fluffy, and tasty
• Carbon dioxide is necessary for photosynthesis for all plants, which in turn produces the oxygen gas that humans need to breathe
• Carbon dioxide is used in pharmaceuticals as a less toxic alternative to more traditional solvents
• Carbon dioxide is used in waste water treatment as a cooling medium in the environmental testing of electronic devices

Photographs:

I also uploaded the photos to the space where you asked that the photos be saved. I saved 31 photos & videos there.

Lemon Juice and Baking Soda

Vinegar and Baking Soda

Vegetable Oil and Alka-Seltzer

Videos:

I uploaded 2 videos to YouTube. The link to my videos are below.

1) Lemon Juice and Baking Soda

2) Vinegar and Baking Soda