1. Water’s Unique Property Lab

2. -waters attraction to other water molecules
Experiment #1:
What is cohesion?
-waters attraction to other water molecules

3. Cohesion: the attraction between like. molecules
Cohesion: the attraction between like molecules. (one water molecule to another water molecule.
- Due to the fact that water is a polar molecule and opposites attract.

4. Experiment #2: What is surface tension?
A property of liquid surfaces that causes the surface layer to behave like a thin elastic 'skin'.
Molecules in a liquid have attractive forces that hold them together.
Molecules on the surface are attracted to molecules from all sides and below, but not from above. ...
Experiment #2:

5. Experiment #3:
Water Alcohol

6. Why did this occur? Density: Mass/Volume
Water in it’s solid form is less dense than its liquid form.
But why?

7. Water expands when frozen.
Again, WHY ?
When frozen, the water molecules slow down and due to their polarity they will line themselves up + to – end thus taking up more volume and lowering it’s density.

8. . . - O
H H H + H - O H O O H H H +
Liquid
Solid

9. Experiment #4 To dissolve or not to dissolve
Likes dissolve likes
Water is polar so it will dissolve any other substance that is polar
A polar molecule has one + and one – end

10. Did salt dissolve in water?
Yes it did
Why?
Salt is NaCl Na+1 Cl-1
Since salt has a + and – end it is polar

11. Did sugar dissolve in water?
Yes it did
Why?
Sugar is a polar molecule

12. Did oil dissolve in water?NO
Why?
water is polar
oil is not polar, it is
what we call nonpolar

13. Did powder soap dissolve in water?NO
Why?
water is polar
soap is not polar, it is
nonpolar

14. What do we use to dissolve grease/oil on our clothes and dishes?
Why?
Grease/oil is nonpolar and soap is nonpolar

15. Experiment #5 : Just flowing along……………..
What occurred?
Why did this occur?

16. Due to cohesion and adhesion
Waters attraction to other substances
Water attracted to the string
Cohesion:
Water attracted to other water molecules

17. Adhesion and cohesion move water up a plant too!!!!

18. Can you now explain why…...
What caused the ink to move up the paper?
-the water picked up the ink and carried it up the paper.
-the water moved up the paper by adhesion (water’s attraction to the paper)
-the water also moved up the paper by cohesion
(waters attraction to other water molecules)

19. Why again……………... Why does this occur? Adhesion is the tendency of
certain dissimilar molecules to
cling together due to attractive forces.
The water molecules are attracted to the ‘sides’ of the graduated cylinder causing the water to rise up on the sides
Water forms a concaved meniscus.
The water molecules are attracted to the sides of the glass container.
Why does this occur?

20. Conclusion questions:
1. Why is water used in most recipes?
2. Why is water used for cleaning, washing clothes, dishes and other items?
3. Why do you think water if the major component of our blood?