monday, march 3 rd : “a” day tuesday, march 4 th : “b” day agenda check lab write-ups ...

Monday, March 3rd: “A” DayTuesday, March 4th: “B” Day

AgendaCheck lab write-upsPre-lab safety items/discussionLab: “Polymers and Toy Balls”Completed lab will be due next class period

Lab: “Polymers and Toy Balls”

Safety Guidelines The latex is in the hood because the vapors are unpleasant! (stinky!)

The ethanol is in the hood because it is flammable!

Keep all of these bottles tightly closed when they are not in use.

Wear gloves when told to do so in the procedure.

Lab: “Polymers and Toy Balls”Lab Discussion

Be patient when rolling the ethanol-silicate polymer into a ball. If it crumbles, a few drops of water will rehydrate it so it can be reshaped into a ball.

Try to get the balls as round as possible. This will make it easier to determine their volume and how high they bounce.

Lab: “Polymers and Toy Balls”Lab Discussion

Remember, this is chemistry class. Use centimeters (cm) when recording the height the balls bounce and use grams (g) to record the mass. You will probably need more than 3 trials to get an accurate bounce height.

Record the bounce height (cm) in Table 1. Record the mass (g) and diameter (cm) in Table 2.Make sure your data has the correct units!

Lab: “Polymers and Toy Balls”Lab Discussion

In the Analysis section:

1) The chemical formulas are: Latex monomer: C5H8

Ethanol-silicate polymer: SiC4H10O3

Remember: ALL lab questions need to be answered using

complete sentences!

Lab: “Polymers and Toy Balls”Lab Discussion

5) Do not use water displacement to measure the volume, the ethanol-silicate polymer will dissolve. Use the formula for the volume of a sphere:

Volume = 4/3 ∏ r3

6) Remember, density = mass volume

Be sure to SHOW ALL WORK and include proper units!

Lab: “Polymers and Toy Balls”Lab Discussion

You may take the latex bouncy ball home at the end of the day.

There are baggies and labels on the back table.

Put your labeled bag on the cart and pick it up after homeroom…

Lab: “Polymers and Toy Balls”

Conduct “Polymers and Toy Balls” lab safely!

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