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.

Particular Properties Read pages 104-105 (Explore Particular Properties) Notes: You will work in teams to investigate the properties of several common chemical compounds. You will organize the compounds based on the results of your investigation. You will learn what is happening at the microscopic level to explain your macroscopic observations. You will be performing 6 different tests on 8 compounds. You will use your observations and logic to sort the substances into groups with similar properties

Write down the Materials List from page 106 into your notebook (You don’t need to include aprons and glasses but write down everything else!) Please note: when the book says “deicer”, it really means “de-icer” Please note: ADD vinegar to the list of materials.

Particular Properties Create a data table in your notebook to record your data. Think about how many columns and rows you will need to record all your data. You will need 7 Columns and 9 Rows! Column Headers are: Compound Appearance Hardness Conductivity (as a solid) Solubility in H20 Conductivity (as a liquid/solution) Relative Melting Point

Particular Properties Fill in the Compounds Column with the names of the 9 (NINE) compounds we will be testing. You can find the list of compounds in YOUR notebook, under the Materials section!

Check Point… What we’re testing [from the book]: Aspirin Cornstarch De-icer Epsom salts Candle wax (paraffin) Sugar Table salt Vitamin C We are testing [added to our list]: Vinegar

Numerical Measurements Relative Comparisons vs. Numerical Measurements There is a difference between measuring and comparing objects. If we felt compelled to group mammals according to hair length we could measure everyone’s hair or we could just estimate instead. We can classify hair as ‘short’, ‘medium’, and ‘long’. We don’t have to MEASURE the hair length in order to group the subjects. This is called a “Relative Comparison”. If we spent the time to measure the average hair length on every mammal, we could group them more accurately but it would take a long time! Medium hair Long hair Short hair

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.