be collected during the experiment and then analyzed. From the data and graph, you will determine what kind of mathematical relationship exists between the pressure and absolute temperature of a confined gas. You may also do the extension exercise and use your data to find a value for absolute zero on the Celsius temperature scale. OBJECTIVES In this experiment, you will • Study the relationship between the temperature of a gas sample and the pressure it exerts. • Determine from the data and graph, the mathematical relationship between the pressure and absolute temperature of a confined gas. • Find a value for absolute zero on the Celsius temperature scale. Figure 1 MATERIALS 125 mL Erlenmeyer flask Vernier LabQuest ring stand Vernier Gas Pressure Sensor utility clamp Vernier Temperature Probe hot plate four 1 liter beakers plastic tubing with two connectors glove or cloth rubber stopper assembly ice Page 45 of 77
Lab 9b PROCEDURE 1. Obtain and wear goggles. 2. Prepare a boiling-water bath. Put about 800 mL of hot tap water into a l L beaker and place it on a hot plate. Turn the hot plate to a high setting. 3. Prepare an ice-water bath. Put about 700 mL of cold tap water into a second 1 L beaker and add ice. 4. Put about 800 mL of room-temperature water into a third 1 L beaker. 5. Put about 800 mL of hot tap water into a fourth 1 L beaker. 6. Prepare the Temperature Probe and Gas Pressure Sensor for data collection. a. Plug the Gas Pressure Sensor into CH1 and the Temperature Probe into CH2 of the computer interface. b. Obtain a rubber-stopper assembly with a piece of heavy-wall plastic tubing connected to one of its two valves. Attach the connector at the free end of the plastic tubing to the open stem of the Gas Pressure Sensor with a clockwise turn. Leave its two-way valve on the rubber stopper open (lined up with the valve stem as shown in Figure 2) until Step 9. c. Insert the rubber-stopper assembly into a 125 mL Erlenmeyer flask. Important: Twist the stopper into the neck of the flask to ensure a tight fit. d. Close the 2-way valve above the rubber stopper—do this by turning the valve handle so it is perpendicular with the valve stem itself (as shown in Figure 3). The air sample to be studied is now confined in the flask. Figure 3 7. Prepare the computer for data collection by opening the file “07 Pressure-Temperature” from the Chemistry with Vernier folder of Logger Pro . 8. Click to begin data collection. 9. Collect pressure vs. temperature data for your gas sample: a. Place the flask into the ice-water bath. Make sure the entire flask is covered (see Figure 4). Stir. Page 46 of 77
Pressure-Temperature Relationship in Gases b. Place the temperature probe into the ice-water bath. c. When the pressure and temperature readings displayed in the meter stabilize, click .
- Fall '10