Properties of Gases

Date Performed: Name: Date Submitted: Partner: Instructor: The Properties of Gases Objective To study the dependence o f the volume of a gas on temperature and pressure. Experimental Data Part A. Charles? Law Part B. Boyle?s Law Sample Calculation Volume of air (cm3) = =2 x 4.5 = 22.1 cm3 Pressure of air (mm Hg) = 965.7 mm Hg + 317 ± 5 mm Hg = 1282.7 ± 5 mm Hg PV product = 1 mL x 1282.7 ± 5 mm Hg = 1282.7 ± 5 mm Hg Results and Conclusion Part A For the Charles? Law experiment temperature and height of air trapped in a tube were measured at different intervals. From the height of air, the volume of air in the tube at each measured temperature was calculated. The volume of air in the tube increased as temperature increased, showing a linear relationship. The value of absolute temperature found from the graph was -259.2 ?C. Part B For the Boyle?s Law experiment volumes were measured to corresponding pressures. The pressure of air was calculated by adding the pressure of the sensor with the pressure of the atmosphere. The pressure of air decreased as volume increased. The relationship of pressure to volume is not a linear function. However the relationship of volume to the inverse pressure is a linear relationship. None of the PV values were the same for the Boyle?s Law experiment. The average PV value was -265.6±5 mm Hg * mL and the standard deviation was -265.6±757508.3 mm Hg * mL. Discussion of Experimental Uncertainty Sources of experimental uncertainty include, systematic uncertainty in which the thermometer used for the Charles? Law experiment could have been miscalibrated then thrown off the accuracy of the procedure. All the values would be either too high or too low. Another source of systematic uncertainty could arise from an incorrectly labeled syringe; this too would throw off the accuracy of the measured values. As for random uncertainty, the values measured with the ruler, thermometer, or syringe which could all have been affected by systematic uncertainty, this would lead to uncertainty of air pressure calculated using the volumes obtain from the syringe in the Boyle?s Law experiment along with the overall volume of air trapped in the tube of the Charles? Law experiment. Graphs Charles? Law Boyle?s Law Temperature (?C) 7.5 23.0 35.0 50.0 65.0 75.0 93.0 Height of air (cm) 4.5 5.0 5.1 5.3 5.6 5.7 6.1 Volume (mL) 1 2 3 4 5 6 7 8 Sensor Pressure (mm Hg) 965.7 644.6 155.6 -0.1 -54.4 -173.7 -230.3 -271.4 Volume (mL) 9 11 13 14 16 17 19 Sensor Pressure (mm Hg) -313.7 -377.0 -430.5 -436.7 -476.0 -493.8 -511.1 Temperature (?C) 7.5 23.0 35.0 50.0 65.0 75.0 93.0 Height of air (cm) 4.5 5.0 5.1 5.3 5.6 5.7 6.1 Volume of air (cm3) 22.1 24.5 25.0 26.0 27.5 28.0 29.9 Volume (mL) 1 2 3 4 5 6 7 8 Sensor Pressure (mm Hg) 965.7 644.6 155.6 -0.1 -54.4 -173.7 -230.3 -271.4 Pressure of air (mm Hg) 1282.7±5 961.6±5 472.6±5 316.9±5 262.6±5 143.3±5 86.7±5 45.6±5 PV Product 1282.7±5 1923.2±5 1417.8±5 1267.6±5 1313.0±5 859.8±5 606.9±5 364.8±5 Volume (mL) 9 11 13 14 16 17 19 Sensor Pressure (mm Hg) -313.7 -377.0 -430.5 -436.7 -476.0 -493.8 -511.1 Pressure of air (mm Hg) 3.3±5 -60.0±5 -113.5±5 -119.7±5 -159.0±5 -176.8±5 -194.1±5 PV Product 29.7±5 -660.0±5 -1475.5±5 -1675.8±5 -2544.0±5 -3005.6±5 -3687.9±5