Date:__________________ pg:______
Water We Talk’n About?
Water is everywhere. It flows freely from our faucets, is constantly swirling around in our cells, and even in
every breath we take. Water is so extraordinary that life on Earth wouldn’t exist without it. Because water is
such an unusual and unique substance it is vital we learn about all of its special properties. As you work
through the activities below, just think about the wonder of water!
In this lab, we will investigate some of the properties of water in an attempt to understand how water
behaves in relation to both our bodies and the environment.
Materials:
 penny
 medicine dropper
 graduated cylinder




water
liquid soap
beaker
paper towel
 Vis-à-vis marker
Part 1 – Cohesion, Surface Tension, and Adhesion
1a. Drop Behavior – Let’s see how many drops of water you can place on the surface of a penny before it
overflows. You will do 3 trials and calculate the average number of drops.
1. How many drops do you predict the penny will hold? ____________________
2. You will have to pick a side of the penny and be consistent throughout your trials…circle which side you
will be using for all 3 trials:
Heads
Tails
3. Using a medicine dropper, count how many drops of water you can place on the surface of a penny
before it overflows. Drop the water slowly enough so you can carefully count the total number of
drops added to the penny until ANY amount of water runs over the edge of the penny.
4. For all three trials, record the number of drops in the data table and calculate the average number of
drops when you are finished.
Trial 1
Trial 2
Trial 3
Average
Number of
Drops
* Caution: make sure you completely dry off your penny between trails!
4. If the number of drops is very different from your prediction, explain what accounts for the difference.
5. How is the penny able to hold so many drops of water? Explain your results in terms of adhesion,
cohesion, hydrogen bonding, and surface tension.
Date:__________________ pg:______
1b. Effects of Detergent – Does adding soap to the penny change your results?
1. With your finger, spread one small drop of liquid soap on the surface of a dry penny.
2. How many drops do you think this penny will hold after being smeared with liquid soap- more, less, or
the same as before? Why?
3. Using the same dropper as before, add drops of water to the penny surface. Keep careful count of the
number of drops, and draw the water on the penny after one drop, about half full and just before
overflowing. Repeat this procedure 2 more times and calculate an average number of drops (you only
have to draw for the first trial).
Diagrams:
one drop
half way full
Trial 1
Trial 2
just before overflowing
Trial 3
Average
Number of
Drops
* Caution: make sure you completely dry off your penny between trails!
4. Did the soap make a difference? Explain.
5. What do the soap molecules do to affect the water molecules in this way?
6. After seeing this example, why do you think we use soap detergent to wash our dishes and clean our
clothes…why don’t we just use water all by itself?
Date:__________________ pg:______
Part 2 – The Climbing Property of Water
Water moves to the tops of tall trees due to capillary action combined with root pressure and evaporation
from the stomata (openings) in the leaves. Water will also climb up paper, and often the migrating water will
carry other molecules along with it.
1. How fast do you think water would climb a string of absorbent paper about 2cm wide? Prediction:
about 1 ml per ________________ (time)
2. Obtain a 50ml graduated cylinder, cut a strip of paper towel that is about 2 cm wide and long enough
to reach to the bottom and hang over the side of the cylinder (inside). See picture below for
clarification. Do not put water or the paper towel in your cylinder just yet.
3. Draw a single medium dot using the Vis-à-vis marker about 6 cm from the bottom of your paper towel
and let it dry completely for a minute. It is critical that this dot does not get wet before starting the
experiment!!
4. Put 10 mL of water into the graduated cylinder and carefully slide the strip of paper towel down the
center of the cylinder so the bottom end is immersed in water and the drop of ink is just above the
surface of the water. Fold the paper over the top side so it doesn’t fall in (or tape the top).
5. Note the starting time. Start time: _______________
6. At 1 minute intervals measure the distance (in ml) the ink has traveled. Complete the chart below
after each minute.
Time (minutes)
0
1
2
3
4
5
6
Distance (ml)
Date:__________________ pg:______
7. How far did the ink travel (in ml)? What property pulls the ink up the paper towel?
8. How do you explain your results? Your explanation should involve capillary action, adhesion, and
cohesion.
Summary
Define and describe at least one observation you made in this lab that demonstrates the concepts listed
below.
Polarity-
Adhesion-
Cohesion-
Capillary Action-
Surface Tension-
Hydrogen Bonds-