WATER AND IT’S PROPERTIES SECTIONS 2.1-2.4, 2.7-2.18 1

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WATER AND IT’S PROPERTIESSECTIONS 2.1-2.4, 2.7-2.18

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DO NOW

1. How do we rely or use water in our everyday life?

2. Why is water so valuable?

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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. Take out your investigating water properties handout.

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DO NOW

1. What is chemical formula for water?

2. What does a water molecule look like? Draw one.

3. List one property of water from the reading that makes it unique.

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OBJECTIVES

1. SWBAT identify unique properties of water by performing a water activity and then discussing the results

2. SWBAT define properties of adhesion, cohesion, polar, nonpolar, and hydrophobic/hydrophillic of water and relate it water activity

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WATER ACTIVITYHow 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?

Use the handout and create a data table and drawing of the penny.

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WHAT DOES WATER LOOK LIKE?Let’s draw it!

Atom:

Molecule:

Polar:

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WATER VIDEO

We can use the properties of water to explain why the large number of drops can be placed on the surface.

https://www.youtube.com/watch?v=aVmU3CLxvgU

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DO NOW

1. Explain why the penny makes a dome shape of water in the “drops on a penny” activity.

2. Explain why a drop of isopropanol causes the dome of water to break.

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OBJECTIVES

1. SWBAT identify unique properties of water by performing a water activity and then discussing the results

2. SWBAT define properties of adhesion, cohesion, polar, nonpolar, and hydrophobic/hydrophillic of water and relate it water activity

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WATER CONTAINS POLAR COVALENT BONDS

Polar:

Covalent:

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WATER CONTAINS HYDROGEN BONDS

-Hydrogen bonds are weak bonds between like molecules

-Partial positive charge attracts a partial negative charge

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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

Adhesion: attraction of water to unlike substance

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SURFACE TENSION:Water pulls in and attracts itself to form a “film” on its surface to form a drop

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WATER DROP SHAPES

-Water has cohesion to itself and forms a nice, round drop

-Round drop on wax paper (not strong adhesion to water)

-As adhesion to glass is stronger and pulls the water, it makes a flatter drop

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WATER ON WAX PAPER

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WATER COHERES TO POLAR, NOT NONPOLAR

-“Like adheres to Like”

-Polar molecules will attach to polar and nonpolar will attach to nonpolar

-Water (polar) has no adhesion to wax paper (nonpolar). It rolls right off.

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DO NOW

1. Explain how to make water not form a drop on a piece of wax. Explain what happens on the molecular level.

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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.

3. 3. SWBAT answer questions on the properties of water using chapter 2 worksheet.

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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

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.

- Remember: Like dissolves Like!

Food coloring in waterOil in water

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AMPHIPATHIC

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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:

-water is polar and can dissolve polar and ionic molecules

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VIDEO

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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:

-How does this relate to biology?

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SPECIFIC HEAT& LIFERelation 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

during cooler times to warm the air

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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

-Killing the aquatic life

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WATER POLLUTION

Why is water important in biology?

https://www.youtube.com/watch?v=fxZ4IMpM45Y

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OIL SHEEN

-Oil Sheen on water

-Oil on top of water in a thin layer

Pollution: How doe we get rid of it?

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HOW TO GET RID OF OIL ON WATER

-Detergent breaks up oil into small drops

-Detergents are amphipathic

have both polar and

nonpolar regions

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