Purpose: Hypothesis: Procedure:

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1 Name: Block: Properties of Water Lab As we have discussed in class and on notes, 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 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. This experiment should be designed and conducted individually. 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. 3. Carry out your investigation. 4. Record your results and display them effectively. 5. Write a conclusion that answers your question. 6. Evaluate your experiment. Purpose: Hypothesis: Procedure: 1

2 Data Collection: Analysis & Conclusion: Station 2: Part A:Cohesion/Adhesion 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. Analyze what you observe and explain what caused it to happen. Observations: Explanation: Part B: Density of Water 1. Add 90 ml of water to a 100mL graduated cylinder 2. Add enough ice to bring the water level to the top edge of the cylinder 3. Immediately measure the temperature of the top (above 100mL mark), middle (60mL mark) and bottom (10mL) of cylinder 4. Repeat the measurements after 4 minutes and when the ice is melted 5. Graph your results using Google Spreadsheets or Excel and staple to this lab. 6. Evaluate your results from the graph and experiement on a separate piece of paper (same as graph?) 2

3 Station 3: Oxygen Capacity of Water OBJECTIVES In this experiment, you will use a Dissolved Oxygen Probe to measure the concentration of dissolved oxygen in water. study the effect of temperature on the amount of dissolved oxygen in water. predict the effect of water temperature on aquatic life. MATERIALS Power Macintosh or Windows PC Vernier computer interface Vernier Dissolved Oxygen Probe Vernier Temperature Probe Logger Pro 100- ml beaker two 250- ml beakers hot and cold water 1 gallon plastic milk container Styrofoam cup PROCEDURE 1. Plug the Dissolved Oxygen Probe into USB Port 1 on the Mac. Connect the Temperature Probe to USB Port 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 C. 3

4 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 ( seconds). At colder temperatures the probe will require a greater amount of time to stabilize. When the readings have stabilized, click Keep. 10. Remove the probes from the water sample and place the Dissolved Oxygen Probe into a beaker filled with distilled water. Figure 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 Stop. 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 this image to yourself or upload it go Google Drive. Print this graph and staple to your lab. 4

5 Data Table 2. Dissolved Oxygen per Temperature Temperature ( C) Dissolved Oxygen (mg/l) 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 survivial of organisms. 5

6 Conclusion & Evaluation Aspect 1: Concluding Aspect 2: Evaluating Aspect 3: Improving the investigation Exceeds (Complete) States a conclusion, with justification, based on a reasonable interpretation of the data Evaluates weaknesses and limitations Suggests realistic improvements in respect of identified weaknesses and limitations Meets (Partial) States a conclusion based on a reasonable interpretation of the data Identifies some weaknesses and limitations, but the evaluation is weak or missing Suggests only superficial improvements Not Proficient (Not at all) States no conclusion or the conclusion is based on an unreasonable interpretation of the data Identifies irrelevant weaknesses and limitations Suggests unrealistic improvements Classroom Skills Classroom Skills Exceeds (Complete) Includes most of the following: Student helps to clean common areas OR Student assists other students when appropriate OR Student attempts to find solutions to problems or questions independently, with group members, or research Discussion fully connects findings or implications to class concepts or real world events with at least one external citation.. Appropriate scientific vocabulary used extensively and accurately At least two (2) credible and appropriate citations used accurately when necessary or directed by assignment Meets (Partial) Includes most of the following: Student is on task and works consistently to complete lab during class period Student leaves lab area clean and prepared for next class Work is completed on time Answers fully address question Limited grammatical errors and conventions Uses scientific language (avoid the use of pronouns like I, you, me, we, our, etc.) and is concise but detailed At least one (1) credible and appropriate citations used accurately when necessary or directed by assignment Not Proficient (Not at all) Any of the following: Missing elements listed in proficient JEOPARDIZES SAFETY Work is late 6