Unit 8: IMF Properties Objectives Able to identify polar vs nonpolar Able to determine associated IMF Able to apply “like goes with like” Words to know Electronegativity Surface Tension Polar Nonpolar Phobia Philo/Phil Hydro Hydrophobic Hydrophilic

Like goes with Like What does it mean if a substance is polar? A polar substance will be attracted to which of these substances? (Polar or nonpolar?) What types of Intermolecular forces (IMFs) could a polar substance have that nonpolar substances would not have? The phrase “like goes with like” means that polar substances will stick with other polar substances and nonpolar substances will “stick” with other non polar substances. p.s. the phrase is most often stated as “like dissolves like.”

Experiment #1 Like goes with Like Materials: Test tube/Holder. Oil. Water. Funnel. Beakers. Food coloring. Paper Towels Observations : Diagram setup below Is food coloring polar/nonpolar? How do you know?

Hydrophobic vs Hydrophilic Hydro = water (hydraulics, hydroponics) Philo Philic  Love (Philosophy) Phobia  Phobic  Fear Hydrophobic = Fears water (nonpolar) Hydrophilic = Loves water (Polar)

“Experiment” #2 Hydrophobic Sand Materials: Spoon, container of sand + water. Do nonpolar (Hydrophobic) things “stick” together? Carefully raise some sand out of the water. Does the sand stick together? Put the sand back in the water (not floating on the top… breaking it) Does the sand “stick” together? What kind of IMF would non polar things have?

Surface Tension and Soap. Surface tension is the result of waters attraction to water (cohesion) and the location of water on the surface… take some physics…

Experiment #3 Soap Boats. Materials: Folder (paper boat), scissors, beaker of soap, poke stick (chop stick/pencil is fine), water, tray (put water in it)

How does soap work? Scenario: Spilled a bunch of oil on hand (oh no~!). Why would rinsing your hand with soap work better than without soap? Consider like goes with like and the polarity if of oil, water, and soap.