WATER
AND IT’S
PROPERTIES
1
SECTIONS 2.1-2.4, 2.7-2.18
DO NOW
1. How do we rely or use water in our everyday life?
2
2. Why is water so valuable?
DO NOW
1. Why were our results so scattered yesterday?
2. When we repeat the penny water/isopropanol
today, what would you do differently?
3
3. Take out your investigating water properties
handout.
DO NOW
1. What is chemical formula for water?
2. What does a water molecule look like? Draw one.
4
3. List one property of water from the reading that
makes it unique.
OBJECTIVES
1. SWBAT identify unique properties of
water by performing a water activity and
then discussing the results
5
2. SWBAT define properties of adhesion,
cohesion, polar, nonpolar, and
hydrophobic/hydrophillic of water and
relate it water activity
WATER ACTIVITY
How many drops of water can you place on the surface
of a penny?
How many drops of isopropanol can you place on the
surface of a penny?
6
Use the handout and create a data table and drawing of
the penny.
WHAT DOES WATER
LOOK LIKE?
Let’s draw it!
Atom:
Molecule:
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Polar:
WATER VIDEO
We can use the properties of water to explain
why the large number of drops can be placed
on the surface.
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https://www.youtube.com/watch?v=aVmU3CLxvgU
DO NOW
1. Explain why the penny makes a dome shape of water in
the “drops on a penny” activity.
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2. Explain why a drop of isopropanol causes the dome of
water to break.
OBJECTIVES
1. SWBAT identify unique properties of
water by performing a water activity and
then discussing the results
10
2. SWBAT define properties of adhesion,
cohesion, polar, nonpolar, and
hydrophobic/hydrophillic of water and
relate it water activity
WATER CONTAINS POLAR
COVALENT BONDS
Polar:
11
Covalent:
WATER CONTAINS HYDROGEN
BONDS
-Hydrogen bonds are weak bonds between like
molecules
12
-Partial positive charge attracts a partial negative
charge
WHAT FORMS A DROP?
-Cohesion causes water to form drops
Cohesion: attraction of water to water
-Surface tension causes the drops to be spherical
-Adhesion keeps the drops in place
13
Adhesion: attraction of water to unlike substance
SURFACE TENSION:
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Water pulls in and attracts itself to form a
“film” on its surface to form a drop
WATER DROP SHAPES
-Water has cohesion to itself and
forms a nice, round drop
-Round drop on wax paper (not
strong adhesion to water)
15
-As adhesion to glass is stronger and
pulls the water, it makes a flatter drop
16
17
WATER ON WAX PAPER
WATER COHERES TO POLAR,
NOT NONPOLAR
-“Like adheres to Like”
-Polar molecules will attach to polar and
nonpolar will attach to nonpolar
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-Water (polar) has no adhesion to wax paper
(nonpolar). It rolls right off.
DO NOW
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1. Explain how to make water not form a drop on a
piece of wax. Explain what happens on the
molecular level.
OBJECTIVES
1. 1. SWBAT continue identify, explain, and
apply the properties of water and how they
apply to water lab using the water lab.
2. 2. SWBAT define hydrophillic, hydrophobic,
capillary action, and specific heat and apply
it to how water is essential to keeping
organisms alive using questioning and the
chapter 2 powerpoint.
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3. 3. SWBAT answer questions on the
properties of water using chapter 2
worksheet.
CAPILLARY ACTION: WATER
CLIMBS UP SMALL SPACES
Because water has both adhesive and cohesive
properties, capillary action is present.
Capillary Action = water’s adhesive property is
the cause of capillary action. Water is attracted
to some other material and then through
cohesion, other water molecules move too as a
result of the original adhesion.
Ex: Think water in a straw
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Ex: Water moves through trees this way
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ADHESION TO GLASS AND
COHESION OF WATER TO WATER
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HYDROPHOBIC AND HYDROPHILIC
-Oil is hydrophobic meaning it does not mix with
water.
-Oil is nonpolar and has no hydrogen bonds
-Water is polar and hydrophilic.
Food coloring in water
Oil in water
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- Remember: Like dissolves Like!
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AMPHIPATHIC
WATER IS THE UNIVERSAL SOLVENT
Solute: substance that is dissolved
Solvent: agent that does the dissolving
Solution: Solute dissolved in solvent
Properties of water that make it an excellent solvent:
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-water is polar and can dissolve polar and ionic
molecules
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VIDEO
SPECIFIC HEAT OF WATER
-Due to hydrogen bonds, water has a better ability to resist
temperature change as compared to other substances
-Energy (Heat) must be absorbed to break hydrogen bonds
-Energy is released when hydrogen bonds are formed
Video
Relation to Biology:
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-How does this relate to biology?
SPECIFIC HEAT& LIFE
Relation to Biology:
-Large bodies of water have a fairly constant temperature compared to
the atmosphere
-Keeps the water within limits to supply life!
-Your body is made of 66% water… homeostasis
-Coastal areas generally have milder climates
-Large water (oceans) bodies can absorb and release heat
-Heat is absorbed from the sun during warmer times and released
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during cooler times to warm the air
WATER DENSITY
-Ice is less dense than water
-Water vapor is less dense then water
Relation to Biology:
-If ice sank, then lakes
and rivers would freeze
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-Killing the aquatic life
WATER POLLUTION
Why is water important in biology?
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https://www.youtube.com/watch?v=fxZ4IMpM45Y
OIL SHEEN
-Oil Sheen on water
-Oil on top of water in a thin layer
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Pollution: How doe we get rid of it?
HOW TO GET RID OF OIL ON WATER
-Detergent breaks up oil into small drops
-Detergents are amphipathic
have both polar and
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nonpolar regions
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