Name:                                                                         Block:

Water Properties Lab

Water has many unique properties that are critical to life on Earth.  The goal of this lab is to study the properties of water and connect each property to a function of life that depends on that property.  Specific Properties to be studied: Surface tensions, Adhesion, Density, Cohesion, & Evaporation

A stalk of celery was placed in a beaker containing water with food coloring 24 hours prior to the lab.  Compare the celery stalk in food coloring water with that in non food coloring water.  Additionally, examine what occurs when a paper towel is bent to connect two beakers, one with liquid and one without.

Analyze what you observe and explain what caused it to happen.

Observations:

Explanation:

Part B: Water Property Stations

Your group will select and conduct an investigation for one of the following water properties.  You will plan, conduct, and evaluate data collected during the investigation; only one group per class will be able to conduct Station 3.

Station 1: Factors Affecting Water Evaporation

Water has a very high heat of vaporization.  This property is important to life on Earth.  In this investigation you will determine the affect that two factors have on the rate of evaporation.

1. Construct a list of possible factors that might affect the rate of evaporation.  Choose two factors to investigate.  A collection of usable supplies are provided on the lab table.
2. Write out the purpose (question), hypothesis (in the if…then form), and procedure for this lab.
4. Record your results and display them effectively by creating a graph; create this in Google Spreadsheets or Excel and staple to this lab packet.

Station 2: Density of Water

1. Construct a list of factors that might affect the density of liquids.
2. The following is a description of how this can be tested; you will need to write a formal procedure.
3. Select water and a second liquid to test densities
4. Write out the purpose (question), hypothesis (in the if…then form), and procedure for this lab.
6. Record your results and display them effectively by creating a graph; create this in Google Spreadsheets or Excel and staple to this lab packet.

General Process for Testing Density:

Add 90 ml of liquid to a 100mL graduated cylinder.  Add enough ice to bring the water level to the top edge of the cylinder.  Immediately measure the temperature of the top (above 100mL mark), middle (60mL mark) and bottom (10mL) of cylinder.  Repeat the measurements after 4 minutes and when the ice is melted

Station 3: Oxygen Capacity of Water

1. Construct a list of factors that might affect the oxygen capacity of water.
2. This is a detailed process and a procedure has been provided.
3. Write out the purpose (question), hypothesis (in the if…then form), and procedure for this lab.
5. Record your results and display them effectively by creating a graph; create this in Google Spreadsheets or Excel and staple to this lab packet.

MATERIALS

 Power Macintosh or Windows PC 100-mL beaker Vernier computer interface two 250-mL beakers Vernier Dissolved Oxygen Probe hot and cold water Vernier Temperature Probe 1 gallon plastic milk container Logger Pro Styrofoam cup

PROCEDURE

1. Plug the Dissolved Oxygen Probe into USB Port 1 on the Mac. Connect the Temperature Probe to USB Port 2.
2. Prepare the computer for data collection by opening clicking “File,” “Open” and select Experiment 19 from the Biology with Computers folder of Logger Pro. The vertical axis of the graph has dissolved oxygen scaled from 0 to 14 mg/L. The horizontal axis of the graph has temperature scaled from 0 to 50C. The Meter window displays the dissolved oxygen and temperature readings.
3. It is necessary to warm up the Dissolved Oxygen Probe for 10 minutes before taking readings. To warm up the probe, leave it connected to the interface, with Logger Pro running, for 10 minutes. The probe must stay connected at all times to keep it warmed up. If disconnected for a few minutes, it will be necessary to warm up the probe again.  As long as you don’t discount the probe, your instructor has done this for you.
4. You are now ready to calibrate the Dissolved Oxygen Probe.  Your instructor has previously calibrated the dissolved oxygen sensor.
5. Obtain two 250-mL beakers. Fill one beaker with ice and cold water. Fill the second beaker with warm water about 40 – 50C.
6. Place approximately 100 mL of cold water and a couple small pieces of ice, from the beaker filled with ice, into a clean plastic one-gallon milk container. Seal the container and vigorously shake the water for a period of 2 minutes. This will allow the air inside the container to dissolve into the water sample.
7. Pour the water from the milk container into the Styrofoam cup.
8. Place the Temperature Probe in the Styrofoam cup as shown in Figure 4. Place the shaft of the Dissolved Oxygen Probe into the water and gently stir. Avoid hitting the edge of the cup with the probe or touching the probes.
9. Monitor the dissolved oxygen readings in the Meter window. Give the dissolved oxygen readings ample time to stabilize (90 – 120 seconds). At colder temperatures the probe will require a greater amount of time to stabilize. When the readings have stabilized, click .
10. Remove the probes from the water sample and place the Dissolved Oxygen Probe into a beaker filled with distilled water.
11. Pour the water from the Styrofoam cup back into the milk container. Seal the container and shake the water vigorously for 1 minute.
12. Repeat Steps 9 – 12 until the water sample reaches room temperature. When room temperature has been reached then begin adding about 25 mL of warm water (40°C – 50°C) prior to shaking the water sample. This will allow you to take warmer water readings. Take dissolved oxygen readings until the water temperature reaches 35°C.
13. When all readings have been taken click .
14. In Table 2, record the dissolved oxygen and temperature readings from the Table window.
15. Save an image of the graph by clicking “Shift + Command + 4” at the same time.  This will allow you to select a portion of the screen to save as an image.  Select the region of the screen that contains both the data table and graph in Logger Pro.  Save the file to the “Documents” folder in the following format: “Last Name_First Name_Properties of Water Lab”  You can now email this image to yourself or upload it go Google Drive.  Print this graph and staple to your lab.

Purpose:

Hypothesis:

Procedure (Not necessary for Station 3):

Data Collection (create a data table):

Analysis and conclusion (preferred typed analysis):

Conclusion/Discussion

Examine the data from each station from the lab.  Discuss and analyze your observation of the various properties as well as their importance to the survival of organisms.