CHM-102 CHM-102 UNCW UNCW Intermolecular Forces: Evaporation of Alcohols and Alkanes General Chemistry 101/102 Laboratory Manual University of North Carolina Wilmington

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Purpose Purpose  To study the effects of Intermolecular Forces, the forces of attraction between molecules, on the physical properties of alcohols and alkanes. Safety Considerations Safety Considerations  Avoid inhaling the fumes from the alcohols and alkanes.  Wash the affected area thoroughly if you contact any of the alcohols or alkanes.  Dispose of all liquid waste materials in the bottle labeled “organic wastes” in the fume hood.

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Procedure Procedure  Connect the Tablet computer, Microlab unit, and the temperature probe as shown in the illustration below.

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Procedure Procedure  To open the Intermolecular Forces experiment on the computer, click on the Applications folder, and select the Microlab prompt. Then double click the “Time and Temperature” prompt as shown below.

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Procedure Procedure  Click on the experiment entitled “Intermolecular Forces-Evaporative Cooling”, as shown below.

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Procedure Procedure  Place the temperature probe in the appropriate sample liquid and wait 45 seconds before starting data collection.  Wrap 1” square of filter paper around temperature probe and secure it with a small rubber band.

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Procedure Procedure  Click the “Start” prompt to begin data collection while the temperature probe remains in the liquid for another 45 seconds.

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Procedure Procedure  Remove the probe from the liquid and place it where it will remain undisturbed, such as on the lab bench or towards the inside of the sink, with the tip extending past the bench about 5 cm. Do not touch the temperature probe while the liquid is evaporating.

CHM-102 CHM-102 UNCW UNCW Intermolecular Forces Calculation Calculation  Stop data collection when a minimum temperature has been reached. A B ΔTΔT The difference intemperaturebetween point A and point B is ΔT for the sample solution.