Do Now for 12/5/12

HW: Review procedure

B19 Creating New Materials

Introduce Activity Write up Today’s Target: To design a Data Table

to record evidence of a chemical reaction.

B19 Creating New Materials Each pair of students will receive:

– 4 hydrogen atoms– 2 carbon atoms– 1 oxygen atom– And 7 “bonds”

Your job is to create a molecule using all the atoms and bonds.

Remember, all bonding sites must be connected. Hint: Carbon has a double bond.

B19 Creating New Materials Your molecule should look like this:

Vinyl alcohol

B19 Creating New Materials

Figure out a way to link your molecule with your partners.– Hint: Where is the only place you can

change a bond without changing the molecule?

B19 Creating New Materials Your molecule should look like this:

Open Bonds

Notice the open bonding site at each end of the molecule. Connect your molecule to the group next to you.

B19 Creating New Materials We have just simulated a chemical

reaction called polymerization– Starting molecule is called a monomer – one

part.

– Long chain is called a polymer – many parts

B19 Creating New Materials

What do the names of the four plastics we’ve studied have in common?– Polypropylene– High Density Polyethylene– Polyvinyl Chloride– Polystyrene

B19 Creating New Materials

What does the prefix “poly” mean? What does the root “mer” mean? What does “monomer” mean?

B19 Creating New Materials

Polymerization – The process of linking thousands of monomers together to form polymers.

Plastics are forms of polymers. Different plastics have different

arrangements of atoms which gives them their different characteristics.

B19 Creating New Materials

We’re going to take the polymer polyvinyl alcohol and see what happens to its properties when we mix it with another chemical compound.

We will cause a chemical reaction and change its chemical composition.

Read the background and challenge on page B-39.

B19 Creating New Materials

Read the procedure and write up the activity.

Each group must design a data table that must be approved by me before you leave class.– Think about what you are observing and

what data needs to be recorded.

Do Now for 12/6/12

Take out your B19 write up and data table.

HW: Analysis 1 through 3 on page B-41 Benchmark tomorrow

B19 Creating New Materials Today’s Target: I will be able to see how

the properties of the products of a chemical reaction are different than properties of the materials that make it up.

Review the purpose and procedure Lab safety Gather data Clean up Review results

B19 Creating New Materials Yesterday we created individual

molecules, and long chains of molecules. What did we call the individual

molecules?

Monomers

What did we call the long chains?

Polymers

B19 Creating New Materials

Going to work with the polymer Polyvinyl Alcohol.

Mix it with Sodium Borate. Observe any changes to the polymers

chemical and physical properties.– Look for evidence of a chemical reaction.– Compare the properties of each starting

compound to the properties of the final compound.

B19 Creating New Materials

Lab Safety– Goggles and aprons– Wash hands when complete– Follow procedure in text book on pages B-40

and B-41. Pay careful attention to step 4!! – Clean all materials thoroughly.– Place your sample on the tray in the front of

the room.

B19 Creating New MaterialsPolyvinyl Alcohol Sodium Borate New polymer

Color

How well does it pour?

Can it be stirred?

Stickiness

Stretchiness

Bounciness

Additional Observations

B19 Creating New MaterialsPolyvinyl Alcohol Sodium Borate New polymer

Color

How well does it pour?

Can it be stirred?

Stickiness

Stretchiness

Bounciness

Additional Observations

Polyvinyl Alcohol

Clear

Slightly thick

Yes

Slightly sticky

No stretch - liquid

No bounce

Liquid

Sodium Borate

Clear/slightly cloudy

Pours easily

Yes

Slightly sticky

No stretch - Liquid

No bounce

Liquid

New polymer

Colorless/transparent

Does not pour

No

Sticks to towel

Stretches a lot when pulled slowly

Bounces slightly

Gel

Exit Ticket

Write your own Key Point on the 3x5 card and turn it in on your way out the door.

Use the information we gathered today to answer your analysis questions on page B-41.

Do Now for 12/7/12

Take out B19 HW: Make sure B19 is ready to be

checked. Read and write up B20

B19 Creating New Materials Today’s Target: I will be able to see how the

properties of the products of a chemical reaction are different than properties of the materials that make it up.

Check HW Go over analysis Key Points Vocabulary Read and write up B20

B19 Creating New Materials

B19 Synthesizing Polymers PVa---PVa---PVa---PVa---PVa---PVa

PVa---PVa---PVa---PVa---PVa---PVa

PVa---PVa---PVa---PVa---PVa---PVa

B19 Creating New Materials

PVa---PVa---PVa---PVa---PVa---Pva

Borate Borate

PVa---PVa---PVa---PVa---PVa---Pva

Borate Borate

PVa---PVa---PVa---PVa---PVa---PVa

B19 Creating New Materials 1. How do the physical properties of the

final product compare to the properties of:

A. Polyvinyl alcohol (PVA) one of the reactants?– PVA is a liquid, and the final polymer is a

gel. PVA is clearer, and can be stirred. The final polymer is stretchable, but is too thick to pour or stir.

B19 Creating New Materials

B. Sodium borate, the second reactant, which you added to the PVA?– Sodium borate is a liquid, and the final

polymer is a gel. Sodium borate is clearer, and can be stirred. The final polymer is stretchable, but is too thick to pour or stir.

B19 Creating New Materials

2. What evidence can you provide that a new substance was formed?– The new substance had a different texture.

It was gel-like. It was also cloudy in color, which was different than the texture and color of the two reactants (Inputs).

B19 Creating New Materials

3. Plastics are a category of materials. Compare the plastics that you worked with in this activity to the properties of the plastics from activity B18. From these two investigations, what can you say about the properties of plastics?

– The plastics in B18 were solid and flexible, some did not react with heat or acetone. The polymers in this activity were liquids. They were flexible, but not solid. From these two activities it seems that plastics can come in all different forms with different properties.

B19 Creating New Materials Key Points

– Plastics are part of a group of chemicals known as polymers, which are made of repeating molecules (called monomers) linked together.» Ex.

– Student Generated! The atoms that make up plastics affects their properties.» Ex.

B19 Creating New Materials

Student Generated! Different materials can combine and have a chemical reaction and create new materials with different characteristics.– Ex.

Vocabulary

1. Chemical reaction: A process during which a substance or substances changes into one or more new substances. The signs of a chemical reaction include: bubbles forming, a color change, a precipitate forming, and an energy change such as a temperature change or light being emitted.

2. Cross-linking: A process in which chemical links are set up between polymer chains.

3. Polymer: Literally “many parts”; many small molecular units bonded to form a molecule with at least1,000 atoms. Natural substances such as cellulose, proteins, and rubber are classified as polymers, as are all synthetic plastics.

4. Monomer: Literally “one part,” or the small molecules that form the units in a polymer chain.

5. Reactants: Chemical substances that enter into a reaction. In an equation, these are generally listed to the left of the arrow or equals sign. The original substances that are present at the beginning of a reaction.

6. Products: In a chemical reaction, the substances that are produced by the reactants; that is, the final substances that are present at the end.