chapter 15 15.1
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Chapter 15 15.1 . Water and Its Properties. Anticipation Guide. Think -Make a Prediction Pair - Discuss your predictions with a partner Share - Your predictions with the class. Could we live without Water?. Water covers about 70% of Earth's surface Water makes up 65-75% of our bodies . - PowerPoint PPT PresentationTRANSCRIPT
Chapter 1515.1
Water and Its Properties
Anticipation GuideOThink-Make a PredictionOPair- Discuss your predictions with a partner
OShare- Your predictions with the class
Could we live without Water?
O Water covers about 70% of Earth's surface
O Water makes up 65-75% of our bodies.O Water can be in the form of…
O VaporO IceO Snow
Water is a Simple Molecule
O 2-HydrogenO 1- OxygenO Oxygen has greater electronegativityO Oxygen has a stronger attraction to
HydrogenO PolarO Universal Solvent
Surface TensionO High Surface TensionO Does anybody know why?O Hydrogen bonds are formed within the
waterO Water molecules at the surface have an
unbalanced attraction and are pulled inward creating a High Surface Tension.
O Creates a skin or elastic wrapO Drop of water can be seen in a spherical
shape.
SurfactantO Decrease surface tensionO Interferes with the hydrogen bondingO Ex: Soaps or DetergentsO Ex: Dishwashing liquid
Vapor PressureO Water has a Low Vapor PressureO What is vapor pressure?O Hydrogen bonds hold the molecules
in liquid water together. O What would happen if water had a
high vapor pressure?
The Density of WaterO Ex: Ice TeaO Solid water has a lower density than
liquid water. O As it begins to freeze its density
increases until….(Refer to chart 15.1 pg. 492)
O Why is ice less dense than liquid water?
O Open framework of molecules in a hexagonal arrangement.
Practice TonightO Pg. 512 #84O Become familiar with:
O Table 15.1 on Pg. 492
Surface Tension ActivityObjectives
O Visualizing the surface tension of water.
O Drop water onto a penny with an eyedropper.
O Visualize the changes in surface tension when a surfactant is added to the water.
InstructionsO One piece of paper per group.O List all group members names at the top
of the paper. O Write the following on your paper:
O # of Drops- Water Only Prediction= Actual # of drops=O # of Drops- Liquid Water and Surfactant Prediction= Actual # of drops=
InstructionsO 1. Take a clean penny and place it on a paper towel.O 2. Load you eyedropper with water. O 3. Take a guess…How many drops can a penny hold?O 4. Write down your guess.O 5. Carefully add water to the penny, one drop at a
time. Counting each drop and observing the shape. O 6. Continue dropping water onto the penny until the
surface tension breaks and the bubble collapses.O 7. Dry off your penny and repeat with the soapy
water and a different eyedropper.