Chapter 3 – Particular Properties

Chapter 3 Write the Section Header “Particular

Properties” in your notebook.

Update your Table of Contents with the correct page number.

Learning Target: I can examine the properties of different substances to sort them into categories based on likenesses and differences.

The Tests we’ll run…(homework if necessary)

In each group:• We are going to divide the tests into four groups: • 1) Appearance and hardness• 2) Relative Solubility (of liquids and of solids)• 3) Melting Point• 4) Conductivity• Each person pick one of the Protocols on pages 108-109. Draw

a step-by-step “cartoon” of your test(s). This will serve as your procedure. Make sure to note any safety issues!

• The person that drew the cartoon is the expert for that test – do what they say! This person is called the “Test Leader” for that experiment.

• If you only have three people, one person should do the Appearance/Relative Hardness test AND another of their choice.

Lab Rules We will be using a camp stove to determine relative

melting points. Long hair and loose clothing must be tied back. Do NOT operate the stove without an adult present.

Anybody who is horsing around and not following directions will be removed from class with a detention and 0 for the lab.

When you are done with your investigation, you must clean all your materials and return them to the kits.

You must clean up your lab station. You must “check out” with me before leaving the lab.

I will check your materials and station to make sure that they are returned to their starting condition.

Paraffin Melting Test:

We will “DEMO” this instead of having each group test it… cleaning the test tubes is a pain in the neck! :)

Epsom salt is NOT table salt! It is actually Magnesium sulfate, a compound containing magnesium, sulfur and oxygen. It is MgSO4. Kosher vs Table salt:Chemically there is little difference between kitchen salts. Both are at least 97% NaCl. But there are significant differences in the way they are made! Table salt is mined from underground salt deposits, and includes a small portion of calcium silicate to prevent clumping. Because of its fine grain a single teaspoon of table salt contains more salt than a tablespoon of kosher or sea salt.  Kosher salt contains no preservatives and is often derived from seawater. It is particularly useful in preserving, because its large crystals draw moisture out of meats and other foods more effectively than other salts.!

The Rest of the Tests

Complete the remainder of the tests in any order you choose.

Follow the instructions of the “Test Leader” for each test.

Day 3

What do we do with the data?

Categorize: try to make categories for your compounds. Can you find any patterns or trends???

Compare categories with other teams…try to come up with at least one “statement” that relates a category to conductivity.

Be awesome and save the world

CATEGORIZATION: don’t do it with people, but do it with this stuff

Group Discussion TimeIn your table group, pick ONE categorization Present it to the class!

Compound

Appearance

HardnessCond (as

solid)Solubility in water

Cond (as a

liquid/sol.)

Melting Point

AspirinWhite powder

Soft no Partially Weak Low

Cornstarch

White powder

Soft No Partially Weak Low

De-icerWhite crystal

Hard No Yes Strong High

Epsom salts

White crystal

Hard No Yes Strong High

Paraffin  opaque Soft No No N/A Low

SugarWhite crystal

Hard No Yes No Medium

SaltWhite crystal

Hard No Yes Strong High

Vitamin cWhite powder

Hard No partially Weak Low

vinegar Clear liquid N/A No N/A weak N/A

Videos of conducting Solid Sodium Chloride - Conductor, or

Not???

Reflect/Connect Reflect/Connect:

• Reflect and Connect, p. 107-108, # 1-3

Reading Sidebar Read “Electrical Conductivity”, p 110-

111• Take notes as you go along.

• Anything in this section is “test-able”… do you feel comfortable that you took enough notes as you read???