9) Measure and record the volume when the plunger stops moving. Note: Keep the syringe in the water bath the entire time. 10) Remove the syringe from the first bath and place it in the second temperature bath. Repeat steps 8 and 9 to measure the new temperature and volume of the gas. 11) Repeat steps 8 and 9 at the remaining water-bath temperatures to obtain a total of five different temperature-pressure readings. Note: It is very important that you go from coldest to hottest. Data Trial 1 Trial 2 Beaker T ( .C ) V (ml) T ( OC V (ml) #1 -5.3 13 - 6, 9 1215 #2 233 14 3.5 14 #3 22.7 16 222 6 #4 56. 2 16 47,5 15,5 #5 74. 5 16 74 16 Analysis of Data: 1. Plot your data points with Temperature on the y axis and Volume on the x axis. 2. What trend do you see? 3. Calculate the linear trendline. It will be in the form y = A . x + B 4. What does B represent? 5. Does it match the expected value of T=273.15.C? 6. If it does not within reasonable error, what adjustment can you do to get better data? 7. Discuss with your group and repeat the experiment. 8. Did it work? Why or why not? VLab 10: Charles's Law and Absolute Zero Objective: To explore the relationship between the temperature and volume of a gas and to experimentally determine the value of absolute zero Apparatus: Beakers filled with water at different temperatures, salt, thermometers, syringes, caps, hot plates, timer, grease, wooden splint, gloves. Background: Charles's Law is the relationship between temperature and volume. As the temperature of a gas increases its volume increases; as temperature decreases volume decreases. In this experiment you will measure the volume of air trapped inside sealed syringes at a variety of temperatures to determine the relationship between the temperature and volume of a gas. You will also extrapolate from your experimental data to determine absolute zero -the temperature at which gas theoretically has volume equal to 0. Absolute zero is 0 Kelvin or - 273.15. C Procedure: 1) Prepare water baths at different temperatures as follows . Add crushed ice and water (total volume 250 ml), followed by 5-6 scoop-full of salt to beaker #1 to prepare a bath at a temperature as close as possible to -10 .C. Add crushed ice and water to beaker #2 to prepare a 0 C-bath. Add 250 mL of room temperature water to beaker #3 to prepare a 20 C-bath. 2) Beaker #4 is on lower temperature plate with water at 40-50 .C-bath 3) Beaker #5 is on hot plate with water bath at about 70-80 .C. 4) Add hot water or ice as needed during the course of the experiment to maintain the temperature of each bath within 15 .C of the desired temperature. 5) Prepare the syringe. Lubricate the plunger of each syringe with silicone grease. Wearing gloves, apply a dab of grease to the black rubber gasket and use a wooden splint to spread a thin layer of grease over the surface of the gasket. 6) Fill the syringe about 1/2-full (10-15 ml) with air, seal the syringe with a syringe tip cap. 7) Quickly push down on the plunger once and wait it get back to its equilibrium position. 8) Measure and record the temperature of the coldest water bath (beaker #1). Place the first syringe in the bath and submerge the syringe just up to the bottom of the plunger (see Figure 1). Hold it there for two minutes, then quickly push down on the plunger once and release it. Figure 1