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Properties of Water Station Lab

Station 1

Pre-Lab Questions: Answer the following questions in your IAN Notebook to the best of your ability. “IDK” and “I don’t get this.” are not acceptable answers. Write down what you think is the right answer and explain it in your own common words.

1.  How do you think water rises from the roots of a tree to the very top?

2.  How do insects walk on the water?

3.  Why does ice float rather than sink?

4.  Why do people become seriously ill, or die, if they go without water for a more than 3 days?

5.  How would life in a lake be affected if ice sank and lakes froze from the bottom up?

6.  If ¾ of our planet is covered in water why should we be worried about conserving water?

7.  Why do you think the ocean is cold at the beginning of spring, but hot at the beginning of winter?

WHEN FINISHED, YOU AND ONE PARTNER MOVE TO A STATION AND GET STARTED WITH THE LAB.

Properties of Water Station Lab

Station 9

Summary

Pulling it all Together

1.  List three properties that you discovered about water?

2.  How do the characteristics of water help the body?

3.  Review your answers to the questions from Station #1.

4.  Which property of water is represented by each question? Explain your answers.

Properties of Water Station Lab

Station 2

Water is attracted to other water molecules like magnets. This is a property of water called cohesion.

Materials:

Wax Paper

Water

Pipette

Straw

1.  Predict what would happen if you scattered water on a slick surface and let wind blow it toward one direction.

2.  Scatter several drops of water around on a piece of wax paper.

3.  Using the straw, lightly blow the water from one end of the wax paper to the other.

4.  Record your observations in your notebook.

5.  Dry up the water on the wax paper and clean up your station.

6.  Answer the questions below in your notebook.

7.  MOVE TO THE NEXT STATION IMMEDIATELY.

Questions:

How did the water drops behave when you scattered them on the wax paper?

What happened when you blew on the water from one end to the other?

Why do you think this happened? How does this show cohesion of water?

Properties of Water Station Lab

Station 3

Related to cohesion is surface tension, a measure of how difficult it is to stretch or break the surface of a liquid.

Materials:

Pennies, beaker of Distilled Water, beaker of Soapy Water, Pipettes, Paper Towels

Procedures

1.  CAUTION: DO NOT MIX THE PIPETTES UP OR MIX THE DIFFERENT SOLUTIONS TOGETHER!

2.  Predict how many drops of water you think a penny will hold. Write this in your notebook.

3.  Add drops of water, one at a time, to the dry surface of a penny. Keep a careful count of each drop added until the water falls off of the penny.

4.  Draw a diagram showing the shape of the water on the penny just before it looks like it is going to overflow, just before you add the last drop.

5.  Now, predict how many drops of soapy water you think a penny will hold.

6.  Repeat Steps 3 & 4

7.  Record your observations in your notebook.

8.  Dry off the pennies VERY WELL and clean up your station. Throw paper towels in the trash can when used.

9.  Answer the questions below in your notebook.

10. MOVE OT THE NEXT STATION IMMEDIATELY.

Questions:

How many drops did the penny hold of distilled water?

How many drops did the penny hold of soapy water?

Why do you think these answers are different?

Explain how detergents and other soaps are able to clean things based on your results in this lab.

Properties of Water Station Lab

Station 4

Water has a high heat of vaporization - the energy required to convert liquid water to a gas. Water's high heat of vaporization helps moderate the earth's climate.

Procedure:

1. Simultaneously stick one cotton swab into a beaker of water while doing the same with a second cotton swab in a beaker of alcohol. Shake off any excess liquid in the beakers.

2. Gently draw straight thin lines of liquid (a few cm long) with each swab on your table top.

3. Blow on the lines for a few seconds, then record which line evaporated first.

4. Write down your observations in your notebook.

5. Clean up your station.

6. Answer the questions below in your notebook.

7. MOVE TO THE NEXT STATION IMMEDIATELY.

Questions:

Which substance had the higher heat of vaporization?

Based on your results explain why water is a much more effective coolant than alcohol for the body.

Properties of Water Station Lab

Station 5

Universal Solvent

Because of its high polarity, water is called the universal solvent. A solvent is a substance that dissolves, or breaks apart, another substance (known as a solute). A general rule that determines whether a substance will dissolve in a solvent depends upon its polarity. Polar solvents dissolve polar solutes and nonpolar solvents dissolve nonpolar solutes.

Procedure:

1.  Fill three cups or beakers with a little bit of water, about ¼ to 1/3 full.

2.  Add a small amount of salt to cup #1, a small amount of sugar to cup #2, and a small amount of oil to cup #3.

3.  Use the stirring rod to dissolve the solids in the water, if possible.

4.  Observe which substances dissolved and which did not, and write your observations in your notebook.

5.  Dump out the solutions, rinse out the cups, and dry them out with paper towels completely. Clean up your station immediately!

6.  Answer the questions below in your notebook.

7.  MOVE TO THE NEXT STATION IMMEDIATELY.

Questions:

Which substance(s) did not dissolve completely in water? Why?

Compare (similarities) and contrast (differences) the terms polar and non-polar.

Properties of Water Station Lab

Station 6

Density

Water is one of the few substances that are less dense as a solid than as a liquid. While most substances contract when they solidify, water expands. This property is due to the hydrogen bonding between water molecules.

Part 1

1.  Place ONE ice cube in the water.

2.  Describe what you see the ice cube doing.

3.  Put the ice cube back in the original cup.

4.  Write down your observations.

5.  Clean up the station.

6.  Answer the questions below in your notebook.

7.  MOVE TO THE NEXT STATION IMMEDIATELY.

Questions:

What would happen to marine life if Solid water was more dense than Liquid water?

How would lakes and rivers react if ice was more dense than liquid water?

How would this affect any of the creatures that lived in or near these areas?

Properties of Water Station Lab

Station 7

Adhesion

Water clings to non-polar molecules.

Procedure:

1.  CAUTION: TURN ON THE WATER SLOWLY FIRST, THEN PUT THE CUP UNDER THE WATER STREAM TO PUT SOME WATER IN THE GLASS.

Put some water in a glass

2.  Pour the water out and observe what is left in the glass

3.  Record your observations in your notebook.

4.  Clean up your station.

5.  Answer the questions below

6.  MOVE TO THE NEXT STATION IMMEDIATELY.

Questions:

What was left in the glass beaker after the water was poured out?

Why do you think this happened?

What property of water allows this to occur?

What organism(s) depend on the adhesion property of water? Why?

Capillary Action- Walking Water Experiment

Station 8

·  Tall Beaker

·  water

·  food coloring

·  celery

·  stirring rod

Procedure:

1.  Choose a color of food coloring

2.  Fill a cup 1/3 full with water and add some of the food coloring. Mix it together well with the stirring rod

3.  Pick one stalk of celery that is broken off on one end to expose the capillary tubes in the celery.

4.  Put the broken end of the celery stalk in the colored water. Make sure the other end of the stalk is sticking out of the water, and make sure the beaker/cup and celery are balanced and do not fall over.

5.  Write down the questions below in your notebook, leaving space between each question for your answers later. READ THE REST OF THE INSTRUCTIONS, THEN MOVE TO THE NEXT STATION IMMEDIATELY.

6.  Wait overnight.

7.  The next day, write down your observations of what happened to the ribs of the celery stalks in the colored water.

8.  Answer the questions below in your notebook.

Questions:

What happened to the celery stalk after it sat in colored water overnight?

Why do you think this happened? Explain your reasoning.

How does the properties of Cohesion and Adhesion explain this phenomenon?

Can you explain Capillary Action based on your observations from this experiment?

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