HONORS BIOLOGY 1A
Lab: Demonstrating The Intensive Properties of Water
Directions: Visit all of the following six (6) stations in any order. Perform any manipulations required
and hypothesize about the cause and meaning of your observations. Record your twelve (12) answers in
your laboratory notebook using complete, coherent sentences and appropriately labeled diagrams.
Station A/B: WEAR THE GOGGLES PROVIDED FOR THIS STATION
The buret on the right contains isopropyl alcohol; the buret on the left contains tap water.
 Rub an inflated balloon on your hair for 30 seconds. This action places a negative static charge on
the surface of the balloon.
 Turn on the stopcock on the left buret and hold the balloon near the stream of water. Observe.
 Repeat, this time using the charged balloon and the right buret (isopropyl alcohol). Observe.
 When you are finished, refill both burets to 50mL with the correct substances.
Questions:
1) What intensive property of water was demonstrated by the behavior of the stream as the balloon
was brought close to the stream? Support your answer with a brief diagram of the water
molecules and the surface of the balloon.
2) How did the behavior of the alcohol stream differ from that of the water when the same static
charge was presented to it? What does this suggest about the physical intensive property of
isopropyl alcohol molecules?
Station C/D: PLEASE DISPOSE OF THE PARAFILM AND SOLUTIONS IN THE WASTE
BUCKET
 Take two squares of parafilm (i.e. waxed paper). Place two drops of water on one square.
Add two drops of corn oil. Observe how the two substances react.
 On the second square, add two drops of corn oil. Add two drops of liquid detergent.
Observe how the two substances react.
Questions:
3) Explain the reaction of the corn oil and water in regards to polarity, cohesion and adhesion.
4) Explain the reaction of the corn oil and detergent. Why did the corn oil react differently with the
detergent? Explain, once again, regarding polarity, cohesion and adhesion.
Station E/F: WEAR GOGGLES FOR THIS STATION
 Into a clean, dry petri dish. Place a full dropper of water. Observe the distribution of the
water in the dish
 Into the other half of the petri dish, place a full dropper of isopropyl alcohol. Once again,
observe the distribution of the solution in the dish.
Questions:
5) What physical intensive property of water was demonstrated by its distribution in the petri dish?
Support your answer with a brief diagram of the water molecules below.
6) Why did the behavior of the alcohol differ? Explain this on a molecular level of organization.
Station G/H: PLEASE DISPOSE OF PAPER TOWELS IN WASTEBUCKET PROVIDED
 Take a dry paper towel and dip one edge into the container of water. Observe the
movement of the water
 Repeat this action using the large class tube. Observe the location of the water
 Repeat again, using the small diameter glass tubes.
Questions:
7) What physical intensive property of water was illustrated by the behavior of the water? Why does
this occur? Support your answer with a diagram of the water molecules and the microscopic
openings in the paper towel.
8) Trees are able to move water 200+ feet against the force of gravity without a pump. The cross
section of a tree you see at this station is actually comprised of millions of tubes with very small
diameters. How does this form of the tree assist the function of moving water in regards to this
physical intensive property.
Station I/J: PLEASE HANDLE THIS APPARATUS CAREFULLY

Gently hold the glass apparatus in your hands and observe the liquid inside.
Questions:
9) The liquid inside the glass apparatus is an alcohol solution that vaporizes (i.e. turns from liquid to
gaseous state) at body temperature. If you were to repeat this process using a similar glass
apparatus filled with water, it would not produce the same results. Why? Explain the concept of
water’s high heat of vaporization based on its molecular structure. Contrast this with the low heat
of vaporization for alcohol.
10) Why does the high heat of vaporization explain the relative stability of aquatic ecosystems?
Station K/L: WEAR GOGGLES DURING AND WASH YOUR HANDS AFTER THIS STATION
 The fungus Lycopodium reproduces by producing thousands of spores. These spores will
germinate when they contact water. However, if they contact water before the optimal
environmental temperature is reached, the spores will fail to germinate.
 Gently take your index finger and stick it through the layer of Lycopodium spores into the water.
Observe.
Questions:
11) The strange phenomenon you just experienced is due to Lycopodium’s secretion of a protein that
enhances the cohesive properties of water, creating high surface tension. Why does Lycopodium
need to secrete this protein and enhance the already high surface tension of water?
12) How have other forms of life (hint: think pond insects) also exploited the high surface tension of
water for their niche? How does their form differ (yet still match the same function)?