Name: ___________________
Class/Period: ______
Date: ________
Water Station Lab: What Makes Water Special?
Directions: In the left column, run the mini-experiment for that water property. In the right column, record all
observations, data, and pictures. Can you identify the property of water? (This is due at the end of the lab). You have 5
minutes at each station!
Property of water!
Station 1 – Uniqueness of Water
Water is a polar covalent molecular compound with ionic
characteristics that make it perfect to support life processes. In fact,
organisms are made up of 40 to 95 % water. The following lab will
introduce you to some of the characteristics of this precious liquid.
Observations/Results/pictures
Draw a water molecule. Label the atoms that make up the
water molecule with their Chemical symbol. If there is
an electrical charge or a partial electrical charge on any of
the atoms, indicate that by writing the symbols on the
atoms:
1. In the Holt Bio Textbook, skim pages 27-30:
2. Define the following
Covalent Bond
Ionic Bond
Hydrogen bond
Station 2- Part I Density – Part I - Water is one of the few
substances that are less dense as a solid than as a liquid. While most
substances contract when they solidify, water expands. This
property is due to the hydrogen bonding between water molecules.
Station 2 Part I Density
Draw what happens when you place an ice cube in a cup
of water.
Density continued (solid vs liquid). Use the ice cube and a
beaker of tap water to answer the following questions
a. Place 1 ice cube into a beaker of Tap water. What
happened AND Why?
Station 2 Part II- Heat of Vaporization
Trial
b. What do you think the definition of Density is?
c. Explain why this property is important to aquatic
organisms.
Clean up: put the ice cube and tap water down the drain
Station 2 Part II- Heat of Vaporization Water has a high heat of
vaporization - the energy required to convert liquid water to a gas.
Water's high heat of vaporization helps moderate the earth's
climate.
Evaporation of
Water (min)
Evaporation of
Ethanol (min)
1
2
3
Average
A. Which substance had the higher heat of vaporization?
(use your data from part A to explain)
Evaporation rates of Water vs. Alcohol. Materials: water,
alcohol, 2- cotton swab, stopwatch
Let’s examine the relative heats of vaporization of water and
Alcohol as follows:
B. Based on your results explain why water is a much
more effective coolant than alcohol for the body.
1. Simultaneously stick one cotton swab into a beaker of water
while doing the same with a second cotton swab in a beaker of
alcohol
2. Gently draw thin lines of liquid (a few cm long) with each swab
on your bench top and
3. Record in Chart how long it takes for each to evaporate. No more
than 4 minutes. If it takes longer than 4minutes use (4+) Record
your data. Repeat for 3X trials.
C. Think about what happens when you boil water for
pasta. Which becomes hot first, the pot or the water in
the pot?
Water has a high specific heat capacity. Specific heat is a
measure of heat capacity, is the heat required to raise the
temperature of 1 gram of water 1°C. Water, with its high heat
capacity, therefore, changes temperature more slowly than other
compounds.
Station 3- Surface Tension: Pennies & Water
Water is attracted to other water molecules like magnets. This is
called cohesion Related to cohesion is surface tension, a measure of
how difficult it is to stretch or break the surface of a liquid.
1. Predict how many drops you will be able to put on the
penny before it overflows by having each person at your
table guess. Write out your hypothesis:
______________________________________________
2.
3.
Now, let’s see how many drops of water you can place on
the surface of the penny before it overflows. Drop water
from the dropper onto the penny, keeping a careful count
of each drop. Do this 3 times and record your data in the
table
Station 3: Penny and Water
Materials: Penny
Water Medicine Dropper
Trial
# of
Drops
1
2
3
Average:
Draw a diagram showing the shape of the water on the
penny after one drop, when the penny is half full and just
before it looks like it is going to overflow.
How many total drops did you get on the penny?
__________________
4. If the number of drops is different from your prediction,
explain your results in terms of cohesion.
Clean up: Be sure to dry the table.
Station 4- Surface Tension: Pennies & Water & Detergent
1. With your finger, spread one drop of detergent on the
surface of a dry penny.
2. Predict how many drops you think this penny will hold
after being smeared with detergent.
3. Write your hypothesis
________________________________
4. Using a dropper, add drops of water to the penny surface.
Station 4- Surface Tension: Pennies & Water &
Detergent Materials: Penny, water, pipette, detergent
Draw a diagram showing the shape of the water on the
penny after one drop, when the penny is half full and just
before it looks like it is going to overflow.
5. Repeat steps 1, 2, & 4 two more times. Record your data in
the table keeping a careful count of each drop.
6. Compare results from Station 3. Did the detergent have an
effect on the outcome?
7. How does the detergent affect the water? (Look back at the
definition for surface tension)
8. Explain how detergents act as cleaning agents.
Station 5: Adhesion & Cohesion. Use beaker A, beaker B, one
marker and 2 strips of filter paper
Trial
# of
Drops
1
2
3
Average:
Use this extra space for answering questions
A. Fill beaker A up with 100mL of water. No water in beaker B!
B. Using a water-based marker make a dot in the center at the
bottom of BOTH pieces of the strip paper
C. Carefully place the strip of paper in each cup. Be sure it sits
straight. (Should not be leaning on the sides of the cup)
-Draw what you observed on each strip:
D. Observe and record what happens by drawing the strip of paper
Strip from beaker A
Strip from beaker B
1. Relate this to what happens when you water a plant.
2. What do you think the definition of adhesion is?
3. Relate this phenomenon to the water property of adhesion
Clean up: Rinse water and dry the water from the beaker. Wipe
down the table if any water spilled onto it. Lay out the strip on a
paper towel to dry.
Station 6 Cohesion: - Use Petri lined under paper towel &the
paper clip to answer the following: * Cover the table with plenty
of paper towel!
1. Fill the petri dish with water. Use the beaker to carefully overfill
(see bubble) with water.
2. As you are pouring, try to get the paper clip to “float” on top of
the surface tension of water. Did you get it? (This can be
challenging)
3. Think of the insect on the water. It is not floating. How does it
stay on top of the water then?
4. What do you think the definition of cohesion is?
Clean up: If the paper clip is dirty or unusable, place it in the
plastic bag. Pour the water from the petri dish down the drain. Dry
your table.
Station 6: Cohesion (Surface Tension)
Record your observations. Draw a picture of your
floating paper clip in the petri dish
Station 7: Universal Solvent- Because of its high polarity, water is
called the universal solvent. A solvent is a substance that dissolves,
or breaks apart, another substance (known as a solute). A general
rule that determines whether a substance will dissolve in a solvent
depends upon its polarity. Polar solvents dissolve polar solutes and
nonpolar solvents dissolve nonpolar solutes.
Station 7: Universal Solvent - Record your
observations
Beaker C-
Materials: Use Water, salt, oil, and beaker C & beaker D
1. Fill beaker C with 30 mL of tap water. Take 3 pinches of salt and
place them into beaker C. Then stir.
Beaker D-
2. What do you notice happens to the salt? Why did this occur?
3. Fill beaker D with 30 mL of tap water. Add 5 to 10 drops of oil
into beaker D.
Predict if the substance will dissolve in water and note
whether each substance is polar, nonpolar, or ionic:
4. What do you notice happens to the oil? Why did this occur?
a. 0.5 grams of NaCl, also known as “table salt” (ionic)
5. What do you think the definition of Solvent ability is?
b. 0.5 grams of sucrose, also known as “table sugar”
(polar)
6. Which substance(s) should not dissolve completely in water?
Why?
c. 5 ml of ethanol (polar)
Clean up: Pour the contents down the drain. Rinse the beakers out
with tap water. Re-set the station.
Station 8 pH- use the pH test strips - Tear off 3 pH test strips.
Use one drop from each sample and place it on the pH test strip
Use your textbook to help you answer the following:
1. What is the pH of an Acid?
1. Using your litmus papers, test the pH of salt water and of fresh
water from the tap. Compare your results.
2. What is the pH of a Base?
2. Which solution is a Base? Neutral?
3. What is the pH of Vinegar? Is it an Acid or Base?
3. What type of solution is the ocean?
4. What is the PH of Ammonia? Is it an Acid or Base?
4. What do you think the definition of an Acid & Base is?
Clean up: throw pH test strips in the trash.
Conclusion - Responses will be graded according to the rubric below:
4
Has a claim directly answering the
question, apt textual evidence
supporting answer, and evidence is
clearly explained tying the examples
to the topic sentence. No
grammatical errors.
3
Has a weakness in the
claim, evidence, or the
explanation. Few
grammatical errors.
2
Weaknesses in two of the
three categories: claim,
evidence, or explanation.
Some grammatical errors.
1
Has weaknesses in all
categories and serious
multiple grammatical
errors.
Conclusion - In a well-formed paragraph, answer the following question: Life depends on water. Pick three
properties of water that you think are the most important for life to exist. Explain how each property works and why it is
one of the most important properties to sustain life.
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________
__________________________________________________________________________________________________