Flubber / Goop
“THE CHEMICAL RECIPE”
In a laboratory, a chemical change does not involve randomly combining substances to form a new product. That
could be very dangerous. You must know how much of each reactant to combine and, in what order to combine
them. If you add the wrong amount of a reactant, or add reactants in the wrong order, you certainly won't get the
product you expect. It’s like following a recipe when you are cooking. You have to follow the recipe to get the
desired results. In the following lab you will create a new different substance. Measure every reactant carefully,
follow every instruction, and you will be rewarded.
Purpose:
• To continue our investigation into chemicals and their use in chemical reactions • To understand he relationship between Reactants and Products
• To continue to work on our lab technique and use of lab materials.
• To continue our understanding of physical/chemical properties and physical/chemical changes.
Procedure:
-------- PREPARE THE BORAX SOLUTION -----------------------------------------------------1. Read through the entire procedure and gather the materials you will need to make the flubber.
2. Obtain a clean 150 ml beaker. (The smaller of the two) Measure out and add 25.0 ml of pure water to this beaker.
3. Measure out 1.00 g of sodium tetraborate (borax). Add the sodium tetraborate to the 25.0 ml of water. Stir to
dissolve as much of the sodium tetraborate as you can. (It won’t dissolve completely)
4. Using a 10.0 ml graduated cylinder, carefully decant out exactly 5.0 ml of the sodium tetraborate solution –
without pouring out any solid material. WAIT.
-------- PREPARE THE (PVA) POLYVINYL ALCOHOL SOLUTION -----------------------------------------------
1. Obtain a second clean 250 ml beaker. Measure 53.0 ml of pure water and place in this beaker
2. Carefully measure out 3.00 g of polyvinyl alcohol.
3. Record observations before combining anything.
4. Add the 3.00 g of polyvinyl alcohol slowly to the 53.0 ml of water while stirring with a glass stirring rod. Once
all of the polyvinyl alcohol has been added, continue stirring continuously so that the powder stays in suspension
(floating around).
5. Using the burner/ring stand apparatus, gently heat this suspension while stirring. Do not allow the solution to
come to a rolling/vigorous boil. Stop heating when the polyvinyl alcohol solids dissolve completely. This is the
most important step. Once the solid particles disappear, remove the solution from the heat.
6. Place 1 to 2 drops of coloring agent into the beaker containing the polyvinyl alcohol solution and stir to evenly
distribute.
-------- MAKE THE FLUBBER -----------------------------------------------------1. While the polyvinyl solution is still HOT, add the 5.0 ml of sodium tetraborate solution you measured earlier to
the polyvinyl alcohol solution while stirring. BE CAREFUL and Stir, Scrape, Stir, Stir, Scrape, Stir…etc! The
material should begin to thicken. Keep stirring for 3-5 minutes.
2. Five (5) mL should be enough, but if it is still a little soupy after 3-5 min of stirring, it may be necessary to add a
few additional drops of sodium tetraborate solution. Do so ONLY if necessary. Try to keep track of how much is
used. Keep stirring and adding borax until all the “soup” is gone.
3. Once the “soup” is gone, use your hands to remove the new substance from the beaker and interact with it.
4. Check Data/Observations for instructions - Record ALL observations.
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THE GOOP - Procedure
-------- PREPARE THE GOOP -----------------------------------------------------1. Measure out ¼ cup of cornstarch into a plastic bowl.
2. Using your graduated cylinder Measure out 30 mL of water. Add a small amount of water at a time to
the cornstarch until the mixture begins to thicken (somewhat like the consistency of yogurt). Stir carefully!
3. Check Data/Observations for instructions - Record ALL observations.
FINALLY - CLEAN UP YOUR AREA!! Wipe your counter top. Thoroughly clean and DRY your
glassware and SHOW glassware to your teacher for inspection. Remember, CLEAN and DRY.
Data and Observations:
For your Data, indicate the observations you made at every step along the way. Be thorough. You should mention
the appearances of substances before and after heating and before and after mixing. You should also note the
physical properties of substances before and after. You could also mention a bit about the chemical reactions and/or
changes involved.
With the PVA Flubber, be sure to: Roll it into a ball and bounce it on a smooth surface Hold it in your hands and
quickly pull the ends in opposite directions. Hold it in your hands and slowly pull the ends in opposite directions.
Hold it up and let it flow from your hand. Make it into a shape, then let it sit on the table top.
With the Goop, roll it into a ball. Does the ball keep its shape? What happens when you move it? What does it do
when you stop moving it? How does the Goop act when you pull it apart slowly and when you pull it apart quickly?
Describe the difference when you close your fist around the Goop quickly and then close it slowly. When does the
Goop act like a liquid? Make it into a shape and then let it sit on the table top.
Error Analysis:
Compare your PVA substance to that of three other groups. Is yours the same (besides color)? Was the flubber
more pliable/elastic or less pliable/elastic? Provide and discuss three possible sources of error that could account for
any differences. Indicate whether or not they are Random or Systematic. No error to calculate.
Post Lab - Discussion:
1.
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10.
What experimental factors might have produced Flubber that was less elastic/pliable? More elastic/pliable?
Compare and contrast the behavior of the flubber to that of the goop.
How do you know that physical and/or chemical changes occurred in this activity?
Based on what you’ve seen, was the creation of Flubber a physical or chemical change? Explain.
What are the physical properties that change as you add sodium borate to the polyvinyl alcohol?
Based on your observations, what might be the effect of adding too much sodium tetraborate to your Flubber?
After making the observations on the dry PVA, how does the water affect the elasticity of the polymer?
Was the creation of Goop a physical or chemical change? Explain.
What caused the Goop to act like a solid or like a liquid?
What are the variables that make Goop a solid? What variables make it a liquid?
Use the Slime Science Article from the web-site and your text to answer the following:
11.
12.
13.
14.
Define: Non-Newtonian fluid.
Is flubber shear thinning or shear thickening?
Is Goop shear thinning or shear thickening?
Define polymer and provide an example of a natural polymer and a synthetic polymer. Page 698 in your text
may be helpful.
15. What is cross-linking for a polymer? Did you see evidence of cross-linking in the lab today? If so, where?
Illustration: Include a neat, well thought out and relevant sketch.
Chemistry@Lopezville