CP Properties of Water Lab ______ / 63 = _______%
Names:
Date:
Introduction: Water is essential to life. This molecule exhibits some unique properties due to its ability to form hydrogen bonds
or because of its polarity. Those properties include: cohesion, adhesion, specific heat capacity, density, pH, and surface tension.
Water is one of the simplest yet most important molecules in the natural world. Our bodies are made up of about 60% water.
Nutrients and minerals need to dissolve in our blood, which is primarily made of water. This is one way we are able to stay alive.
As you complete this lab, you will be investigating the properties of water. It is important to refer back to your notes on sections
2.1 and 2.2 during this lab.
Before beginning the lab, define the following terms using only your notes. These terms will be used throughout the lab. (8pts)
1. Polarity (Polar Molecule):
2. Hydrogen Bond:
3. Adhesion:
4. Cohesion:
5. Surface Tension:
6. High Specific Heat/specific heat capacity:
7. Nonpolar Molecule:
8. Universal solvent:
Label the following water molecule.
1. Put a + sign and a capital H on the two positive hydrogen ends, put a negative sign and a capital O on the oxygen atom.
2. There is a line connecting a hydrogen atom from one water molecule to the oxygen atom of the second water molecule.
Label this line with the term hydrogen bond. (3pts)
Drawing:
* It is important to make predictions for each station before you start the activity at that station. *
Station 1: The Universal Solvent
1. What kind of substances do you think water can dissolve? (1)
____________________________________________________________________________________________________
2. Can it dissolve everything? (1)
____________________________________________________________________________________________________
Prediction: What will happen when you mix salt, sugar, and sulfur in three separate beakers of water?
3. Answer to prediction question: (1)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
Procedure
1. Fill all three beakers approximately ¾ full with water.
2. Use a scoop to add a small amount of salt, about the size of a pea, into beaker A. Stir.
3. Record your results in the table below.
4. Use a different scoop to add a small amount of sugar into beaker B. Stir. Record results.
5. Use the third scoop to add a small amount of sulfur into beaker C and stir. Record results.
4. (3pts)
Beaker A (NaCl (Salt) & Water)
Beaker B (Sucrose (sugar)
and Water)
Beaker C (Sulfur and
Water)
Reaction
5. Go back in your notes to our discussion of polarity and solutions. This information should help you properly explain what is
going on between these three beakers. These words may help you answer the next three questions: polar, nonpolar, solution,
solvent, and solute. (3pts)
A. What happened in beaker A? Why?
____________________________________________________________________________________________________
____________________________________________________________________________________________________
B. What happened in beaker B? Why?
____________________________________________________________________________________________________
____________________________________________________________________________________________________
C. What happened in beaker C? Why?
____________________________________________________________________________________________________
____________________________________________________________________________________________________
6. Now, look back at your introduction to this lab, re-read it, make a connection. How is this station something you can apply to
living things? (Helpful words to use in your answer: salt, sugar, non-polar substances, and blood)? (2pts)
Station 2: Cohesion/Polarity
Prediction:
1. What will happen when you drop water drop by drop on a piece of wax paper? (1 pt)
___________________________________________________________________________________________
2. What will happen when you drop oil drop by drop on a piece of wax paper? (1 pt)
__________________________________________________________________________________________
At this station, you will be investigating the behavior of water, which is polar, on wax paper, which is nonpolar.
Procedure Step One: Using a disposable pipette marked water, drop several drops of water across several places on the wax
paper. Place a toothpick in the middle of one of the drops, move the drop of water around the wax paper bumping it into the
other drops of water on the paper.
3. What property of water allows it to build up on the wax paper and form a big bubble on the wax paper? (1)
__________________________________________________________________________________________
4. Why do you think water was able to do this? (think about polarity and non polarity) (1)
__________________________________________________________________________________________
Procedure Step Two: Using a disposable pipette marked oil, drop several drops of oil across several places on the wax paper.
Place a toothpick in the middle of one of the drops, move the drop of oil around the wax paper bumping it into the other drops
of oil on the paper.
5. What happened between the oil and the wax paper? (1)
__________________________________________________________________________________________
6. Why do you think that happened with the oil and wax paper? (Think about like dissolves like) (1)
__________________________________________________________________________________________
7. How can you apply what happened in this simulation to living things? Use the terms dissolving, polar, and nonpolar in
your answer. Hint: what is your blood made of? What gets dissolved in your blood? Why is it a good thing your blood is
not made of oil? (2 pts)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
____________________________________________________________________________________________________
____________________________________________________________________________________________________
Station 3: Surface Tension
Steel has a density of 7.8 g/cm3 while water has a density of 1.0 g/cm3. Will a steel pin float in water?
Prediction:
1. What will happen when you place a pin on the top layer of water in a filled petri dish? (1)
___________________________________________________________________
2. What will happen to the pin if you drop a drop of dish soap into the petri dish? (1)
___________________________________________________________________
Procedure
1. Fill the cup or Petri dish completely with water.
2. Slowly and gently add one penny at a time until water begins to drip down the side of the vessel.
3. Observe the profile (side view) of the water in the glass.
4. Balance the pin on one end of the paper clip. Holding the other end of the paper clip carefully place the
pin on the surface of the water. Try not to disturb the water during this process.
5. Observe the profile (side view) of the pin on the surface of the water.
6. Put a drop of soap on the water next to the pin. Describe what happens to the water in your science journal.
Bent paper clip
3. The density of a steel pin is greater than the density of water, so it should not float based on this idea alone. Explain what
property of water allows the pin to float. (1)
___________________________________________________________________
4. How is this property of water important to living things? Think about a water spider or insects that walk on water. (2)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
5. What happened after placing a drop of dish soap into the petri dish? (1pt)
___________________________________________________________________
6. Explain why this happened to the pin based on your knowledge of mixing polar and non-polar substances . (1)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
Station 4: Capillary Action
Prediction: What will happen when you place a hollow capillary tube (which mimics the tubing system in a living organism) in a
petri dish filled with colored water?
1. Answer to prediction: (1pt)
___________________________________________________________________________________________
Procedure: Stand a hollow capillary tube up and into a petri dish filled with (colored water).
2. What happens to the solution when the tube is placed in it? (1)
___________________________________________________________________________________________
3. What property of water is being shown here? (1)
___________________________________________________________________________________________
4. How does life depend on this property of water? (think about blood in the body, and water moving from the ground ten
feet up to the leaves in a tree) (2)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
Station Five: Teacher Demo: Density/High Specific Heat/Specific Heat Capacity
Predictions:
1. What will happen when ice is placed in a beaker filled with water? (1)
__________________________________________________________
2. What will happen to ice when it is placed in a beaker of alcohol? (1)
_________________________________________________________
Ice is added to a beaker of water, and then ice is added to a beaker of alcohol.
3. What happened when ice was added to water? Why did this occur? (Hint: think density and hydrogen bonds) (2)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
4. What happened when ice was added to alcohol? Why did this occur? (Hint: think density) (1)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
5. How is what you witnessed (density) in this station very important for aquatic life in the winter when lakes freeze? (2)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
6. Apply the property of high specific heat to the lake scenario. (How is the water below the ice able to stay in liquid form) (2)
____________________________________________________________________________________________________
____________________________________________________________________________________________________
Additional Questions: (12pts)
1. When you make a pitcher of iced tea you add scoops of the sugar mix to a container of water. What property of water
allows it to dissolve the sugar mix? (1)
_________________________________
2. What would the water be considered in this solution? The sugar? (2)
Water = ________________________
Sugar = ________________________
3. Because water is ___________________ it has the ability to form ________________________ bonds.
4. Because water can form ___________________ bonds it can stick to other water molecules giving it the property of
______________________.
5. Because water can form bonds with other polar molecules, it has the property of _______________________.
6. Because water can form ______________________ bonds, it has the ability to resist extreme changes in temperature, this
is known as the property of _______________________________________.
7. Pick one of the properties of water that you learned about and describe to me how life is dependent upon that property of
water. (2)