Wednesday, February 20, 2019
Vapor Pressure and Heat Evaporation Lab Report
vaporisation Pressure and Heat of Vaporization Introduction ?Evaporation is the process of a eloquent becoming vaporized. When a liquid is placed into a impris unitaryd space some of the liquids ordain evapopace. Evaporation of the liquid depends on the specialism of the intermolecular forces that are between liquid molecules. During the evaporation process of the liquid, innovative tout molecules exerts nip in the slicked container, while some of the hired gun condenses back to the liquid state. ?If the temperature inside the container is kept ceaseless, because the equilibrium at some point testament be reached.When the equilibrium is reached, the rate of condensing is equal to the rate of evaporation and the rate of vapor embrace will remain constant as long as the temperature in the sealed container does non change. ?The relationship between the vapor haul of a liquid and temperature is described in the Clausius-Clayperon equation lnP= ? Hvap / R (1/T)+C. where 1nP is the natural logarithm of the vapor pressure, ? Hvap is the change in instigate vaporization, R is the universal gas constant, which is (8. 31 J/molK), T is the absolute, or Kelvin, temperature, and C is the constant that is not related to heating system capacity.Therefore, Clausius-Clayperon equation does not only describes how vapor pressure is affected by the temperature, but relates to the factors of heat vaporization of a liquid. ?The point of this experiment is to determine the relationship between the pressure and temperature of the volatile liquids. The pressure will be heedful in a sealed body of peecraft that contains different types of liquids such as methanol, ethanol and propanol. It will be measured several times at different temperatures. At the conclusion of this experiment, the heat of vaporization will be fitted to be calculated.Materials ?To be able to complete this lab procedure, the materials that are needed is a Vernier computing machine interface , a Vernier shooter Pressure Sensor, temperature probe, rubber stopper assembly, tensile tubing with ii referors, hot plate, ice, one twenty milliliter syringe, one 400 milliliter beaker, dickens 125 milliliter Erlenmeyer flasks, one 1 liter beaker, ethanol, methanol, and 1-propanol. Methods ?The first foot footstep in performing this experiment is to father and wear goggles. The alcohols used in this experiment are flammable and poisonous.The morsel step is to obtain the materials that are needed and set them up as accordingly. The third step is to use a hot plate to heat 200 milliliters of water in a 400 milliliter beaker. The one-quarter step is to prepare a inhabit temperature water bath in a 1 liter beaker. The fifth step is to tie the Gas Pressure Sensor to channel one of the Vernier computer interface, then connect the Temperature Probe to channel two of the interface and then connect it to a computer. The sixth step is to use the clear tubing to connect the white stopper to the Gas Pressure Sensor.The white stopper must(prenominal) be twisted snugly into the neck of the Erlenmeyer flask, to avoid losing any of the gas that will be produced when the liquid starts evaporating. The most important thing to do is to remember to close the valve on the white stopper. ?The seventh step is to fawn in 3 milliliters of methanol into the 20 milliliter syringe that is donation of the Gas Pressure Sensor accessories. status the syringe onto the valve of the white stopper. The eighth step is to start the Logger Pro program and open the cross-file 34 Vapor from the Advanced Chemistry with Vernier folder. The ninth step is to click collect to begin collecting selective information.The first measurement will be the pressure of the air in the flask and the room temperature. Place the Temperature Probe near the flask. When the pressure and temperature readings are stabilized, click keep to criminal record the readings. The tenth step is to add methanol to the flask by porta the valve below the syringe, push down on the syringe to inject the 1-propanol and apace close the valve. Afterwards, remove the syringe from the stopper and monitor the pressure and temperature readings. ?The 11th step is to place the stoppered flask into the 1 liter beaker of room temperature water.Place the Temperature Probe in the water bath and monitor the pressure and temperature readings. The ordinal step is to add a small amount of hot water to warm the water bath by only a hardly a(prenominal) degrees. Stir the water with the temperature probe and monitor the pressure and temperature readings. For the thirteenth step, ingeminate step twelve until five trials are completed. Add hot water for each trial so the temperature of the water bath increases. After the fifth trail is recorded, open the valve to release the pressure in the flask and modify of the alcohol as directed.The fifteenth step is to end the data assembly and record the pressure and temperature readings in the data table. When recording the data, record the pressure valve of the first data point as Pair for trials one and two and record the temperature for trial one. Record the pressure value of the second data point as Ptotal for trial two as well as the temperature. The remaining values are recorded as Ptotal for trial two as well as the appropriate temperature. The last and final step is to clean the work area. Data Table Methanol effort 1 Trial 2 Trial 3 caterpillar track 4 principal 5 Ptotal (mmHg) 103. 1 04. 5 105. 8 101. 9 Pair (mmHg) 101. 3 102. 4 103. 3 104. 4 105. 2 Pvap (mmHg) 0. 7 1. 2 1. 4 2. 7 Temperature (Celsius) 22. 6 25. 8 28. 3 31. 2 34. 0 ethanol Trial 1 Trial 2 Trial 3 Trail 4 Trail 5 Ptotal (mmHg) 106. 3 94. 7 98. 9 112. 9 Pair (mmHg) 100. 8 100. 8 92. 78 96. 0 103. 4 Pvap (mmHg) 5. 4 1. 92 2. 9 9. 5 Temperature (Celsius) 23. 9 24. 0 0. 3 9. 9 31. 7 Propanol Trial 1 Trial 2 Trial 3 Trail 4 Trail 5 Ptotal (mmHg) 101. 7 104. 9 106. 1 10 8. 3 Pair (mmHg) 100. 4 101. 1 102. 2 103. 1 104. 0 Pvap (mmHg) 0. 6 2. 7 3. 0 4. 3 Temperature (Celsius) 23. 8 23. 7 0. 2 6. 5 29. 1 Discussion At the end of this experiment, the results we obtained change because of the different temperatures and pressures that we observed. During the evaporation process of the liquid, gas molecules exerts pressure in the sealed container, while some of the gas condenses back to the liquid state. If the temperature inside the container is kept constant, then the equilibrium was reached. When the equilibrium is reached, the rate of condensation is equal to the rate of evaporation and the rate of vapor pressure will remain constant as long as the temperature in the sealed container does not change.
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