Investigation Sequence

Title

Evaporation and Condensation

Written by:

Laura Gausman & Chris Kuehler                 Date

 

Focus Questions

What is evaporation? What is condensation?

Concepts

Content: Earth, Physical, & Life

Evaporation is a liquid changing into a gas while condensation is a gas changing into a liquid.

Cross cutting concepts

 

Science Practice

 

Personal, Social, Technology, Nature of Science, History

 

Background information

Evaporation is the process that changes a liquid to a gas and that different liquids may evaporate at different rates. Condensation is the process in which changes a gas into a liquid. It will depend on the temperature on how these activities work.

Activity Sequence

1. Water, Water Everywhere and not a Drop to Drink.
2. Lose Some Weight---Evaporate
3. Dew Drop Inn
4. Frosty the Snow Can
5. Evaporation—A Paint Sensation
6. Evaporation
7. Condensation

Activity Descriptions

Activity 1
Water, Water Everywhere and not a Drop to Drink
Materials:
Large bowl, heavy glass cup, (shorter than the bowl is deep) teaspoon, clear plastic wrap, clear cellophane tape, penny, blue food coloring, newspaper or paper towels, salt
Procedure:
1. Imagine that you are on a shipwrecked on a desert island in the middle of the ocean. You have no food and some supplies from you ship but not a single drop of drinking water. You have to figure out some way to make the salt water from the ocean safe to drink. What can you do?
2. Listen to the responses. Do not comment on accuracy.
3. Put tape water in a bowl to a depth of about 2 inches.
4. Add ten drops of blue food coloring and 2 or 3 teaspoons of salt.
5. Mix well, until salt is dissolved.
6. THIS IS YOUR OCEAN
7. Stand the heavy glass cup in the center of the bowl, so it is surrounded by the salt water.
8. Put a loose covering of plastic food wrap over the top of the bowl.
9. Tape the plastic wrap to the sides of the bowl so that no air can get in or out.
10. Tape a penny to the outside of the plastic wrap directly over the center of the glass.
11. Make sure that the weight of the penny makes the plastic wrap slant way down toward the center of the glass.
12. Put the bowl on a flat surface outside, where it will get a lot of sunshine.
13. Check the bowl every hour for four hours.
14. Have the student’s journal what they observe.
15. Do you see any droplets of water on the bottom of the plastic wrap?
16. How do you think the water got there?
17. At the end of four hours take the plastic wrap off.
18. What color is the water in the glass?
19. What do you think happened to the blue food coloring?
20. Make sure your hands are clean; dip your finger in the glass to get a drop or two of water on the tip of your finger?
21. Taste the Water.
22. Is it salty?
23. Record the results,
24. Write an explanation in your own words.


Activity 2
Lose Some Weight Evaporate!
Materials
2 large plastic cups, 2 disposable paper or plastic cups, 1 strait pin, 1 plastic drinking straw, 1 paper towel, rubbing alcohol, water, metric ruler, scissors, tablespoon, safety goggles
Procedure
1. Put on safety goggles.
2. Measuring the length of the straw, ask your partner to push the pin through the exact center of the straw.
3. Stand the two large cups near each other on the table and rest the pin on the rims of the two cups.
4. If the straw is not balanced you may need to adjust the pin.
5. Pour about 2 tablespoons of water into one of the smaller cups.
6. Have an adult pour 2 tablespoons of rubbing alcohol in the other small cup.
7. Cut two strips of paper towels measuring 1 inch wide, and 6 inches long.
8. Have an adult dip one strip in the alcohol and you dip it in the water.
9. Make sure they are both completely wet.
10. Touch strips on side of cup to some of the excess liquid comes off.
11. Hang the strips on opposite sides of the straw.
12. Move until the straw is balanced.
13. Watch the straw as the water and the alcohol evaporate.
14. Which side seems to be losing weight fastest?
15. What is causing one side to lose faster than the other?
16. Does water or alcohol evaporate faster?
17. Record answer in science journal.
18. How can you tell?


Activity 3
Dew Drop Inn
Materials:
Clear glass jar with lid, ice, water
Procedure:
1. The Dew Drop Inn has a problem…. WET WINDOWS. In the winter it is colder outside the hotel than inside, and water forms on the inside of the windows. In the summer it is colder inside the hotel than outside, and water forms on the outside of the windows? Can you explain why?
2. Have students record why in their science journals.
3. The following experiment will help you figure it out.
4. Ask an adult to fill the jar half full with hot tap water.
5. Put the lid on the jar and place it on the table.
6. In a second jar, fill it half full with cold water and a few ice cubs.
7. Put the lid on the jar and place it on the table with jar 1.
8. Watch the jars.
9. Is the water forming inside the jar or outside?
10. From what you have learned about evaporation and condensation, explain why.
11. Write answer in journal.
12. What jar is like The Dew Drop inn windows in the summer and how about winter.
13. Explain
14. Record answer in journal.


Activity 4
Frosty The Snow Can
Materials:
Clean, empty metal food can (label removed), crushed ice or small ice cubes, salt, teaspoon, dishtowel, adhesive tape, spoon.
Procedure:
1. In the "Dew Drop Inn," you saw how water molecules as a gas in the air would change into a liquid on the outside of a container if the container were cold enough. Lets find out what will happen if the container is really cold. What do you think will happen if the container is really cold?
2. Have students record why in their science journals.
3. The following experiment will help you figure it out.
4. Make sure that the tape is put around the top of the cans, so the sharp edges are covered.
5. Dry out the inside of the can with the dishtowel.
6. Place three teaspoons of salt into the can.
7. Fill the can about half way with crushed ice.
8. Add three more teaspoons of salt.
9. Fill the can almost to the top with ice and another three teaspoons of salt.
10. Hold the can near the top and mix the ice-salt mixture with a spoon.
11. Keep stirring until something happens on the side of the can.
12. Ask the students if they noticed any water on the outside of the can.
13. Ask the students what happened.
14. Have the students record their predictions in their journals.
15. Ask the students how this might relate to frost on the ground.


Activity 5
Evaporation----- A Paint Sensation
Materials:
Newspaper, white notebook or typing paper, pencil, rubbing alcohol, water, 6 paper cups, crushed holiday egg dye tablets, teaspoon, 6 cotton swabs, safety goggles one per person
Procedure:
1. Put your safety goggles on.
2. When you and your parents paint your house what process takes place for the paint to dry?
3. Have students record their guess in their science journals.
4. The following experiment will help you figure it out.
5. Spread newspaper over your work area.
6. Pour the dye into one of the cups
7. Crush each of the other dye tablets and put each into separate cups.
8. Separate the cups into two groups.
9. In one of the groups put 2 teaspoons of water into each cup and mark it with a W.
10. In the other group have an adult put two teaspoons of rubbing alcohol into each cup and mark it with an A. (Make sure to replace the lid on the rubbing alcohol).
11. Fold another piece of notebook or typing paper in half and draw the same picture on both sides.
12. Use a cotton swab to paint one side using the paint from a cup marked W.
13. Paint the other side with a cotton swab using the paint from a cup marked A.
14. Have your students think about what they learned in "Lose Some Weight---Evaporate" and have them predict which picture will dry first.
15. Have them record their guesses in their journals. Have them watch the paintings and see which dries first.
16. Have the student’s record what happened and compare it to their journal entry.


Activity 6
Evaporation
Materials:
Plates, (not paper) one purple, orange, black crayon, (for each group) water, sponge,
measuring cup, humidity detector (optional)
Procedure:
1. Teacher wipes a wet sponge across the chalkboard.
2. Have the students watch and make observations about what happens.
3. Ask where does the water on the board go? What happens to puddles after it rains? Where does the water go? Have you ever seen clothes hung out to dry in the sun and wind? Where does that water go?
4. Do not tell them if there answers are right or wrong at this point.
5. Divide into partners.
6. Give each pair a plate and three different colors of crayons.
7. Have students make a shallow puddle on their plates.
8. They should make a purple circle around the puddle.
9. Have each group put their plate in different parts of the room.
10. Let the plates sit for about an hour.
11. Have the students make some predictions about what will happen to the puddles of water.
12. Possible questions, Will the puddle be the same size, will it be larger or smaller, what if we left it in the spot for an hour.
13. Check about an hour later, each pair should make an orange circle around their puddle. If it has changed any.
14. Students can compare puddles.
15. Have the pairs leave their plates in the same spot for another hour.
16. During this time you may have them compare their predictions to what happened.
17. Have them predict what they think will happen in another hour.
18. Have them record that in their journals.
19. Possible questions What will your puddles look like in an hour, what will happen to the water, where does it go, do you think their will be a puddle left.
20. Have them check their puddles, and put a black circle around the puddle.
21. Have the groups compare puddles.
22. Have a discussion about what happened to the puddles, possible questions.
23. Is there a difference in how fast the puddles are evaporating in the different parts of the room, Who’s puddle shrunk fastest, or evaporated faster, where did the water go, what types of places help evaporation to happen faster?
24. Teacher may want to direct to evaporation but, do not force.
25. What did you think the puddle would look like in the morning if we leave it here all night?
26. Have them record response in journal.
27. The next day have pairs observe their plates.
28. Ask: What happened to the water, where did the water go, what is the name for water going from liquid to the air.
29. How does this relate to when you are done taking a shower and you hang your towel up to dry?


Activity 7
Condensation
Materials:
Glass jars, ice cubes, water, paper clips, 8-10 Petri dishes or shallow plates, 4-5 tins lids, salt.
Procedure:
1. Ask the class questions like what are clouds? How are they made? Have you ever seen a cloud on the ground before? What is a cloud (fog) on the ground called? How is fog made? In the winter, when you walk outside, what happens to your breath when the cold air hits it?
2. Have students record their answers in their science journals.
3. The following experiment will help you figure it out.
4. Remember in the Dew Drop Inn activity when filled the jar up with cold water.
5. Can you remember what they noticed on the outside of the jars where it might have come from?
6. Have students record what they remember in their science journals.
7. Now divide the students into four or five groups.
8. Give each group a two Petri dishes, two paper clips, and one tin lid.
9. Have each group place the paperclips in one of the Petri dishes
10. Next have them set the tin lid on top of the paper clips.
11. Have them place 6-10 salt crystals on the tin lid.
12. The teacher will then pour a thin layer of water into each Petri dish making sure that the tin lid does not get any water on it.
13. Then have each group place the other Petri dish on top of each set making sure that no water splashes onto the tin lid.
14. Let the setup sit for up to a half hour.
15. Ask the students what they think will happen. Ask them what will happen to the salt and why are there drops in the lid instead of salt?
16. Record it in their science journals.
17. Explain that the water evaporated from the dish and created air that had high humidity in the dish. Water from in the air collected around each of the salt crystals until each of them dissolved. Now all that is left is the water on the lid. How is this condensation
How does this relate to the fog when you wake up in the morning?

Dr. Robert Sweetland's notes