11 April 2012
The Determination of the Heat of Vaporization of n-Pentane
Introduction Section:
The purpose of the Heat of Vaporization for Normal Pentane (n-pentane) Laboratory Experiment is to determine the heat of vaporization of n-pentane. This experiment was performed as a class. Each pair of partners had to go to the monometer and take the various measurements in order to determine the heat of vaporization.
Experimental and Theory Section:
PLS (cm) PRS P mmhg T° C T (K) ln(P) -1000/RT
84.5 24.6 599 29.3 302.45 6.395261598 -0.397682418
85.55 23.7 618.5 30 303.15 6.427297192 -0.396764135
85.5 23.55 619.5 30.3 303.45 6.428912701 -0.396371881
86.2 22.8 634 30.9 304.05 6.452048954 -0.395589697
86.6 22.3 643 31.1 304.25 6.466144724 -0.395329655
86.8 22 648 31.5 304.65 6.473890696 -0.394810594
87.2 21.6 656 31.8 304.95 6.486160789 -0.394422192
87.5 21.4 661 32 305.15 6.49375384 -0.394163681
88.1 20.6 675 32.6 305.75 6.514712691 -0.39339018
88.5 20.3 682 32.9 306.05 6.525029658 -0.393004566
89.1 19.7 694 33.4 306.55 6.542471961 -0.392363554
The monometer was already pre-set up before the laboratory section started. Each group went up one by one with the aid of Professor Nelson to the collect the various measurements. Each pair of partners had to read the left and right side of the mercury pressures in the barometers and read the temperature at which the system was. Each pair of partners collected this data, which resulted in eleven different observations performed. The data numbers slowly increased between the pressure and temperature as the experiment progressed.
With this data, a graph can be created. The graph is a typical one-quadrant graph with an x-axis and y-axis. However, for this experiment, the x-axis would be _____ and the y-axis was replaced with ________.
The relationship between vapor pressure and temperature is given by the Clausius-Clapeyron: ln(P_2/P_(1 ) )=〖-∆H〗_vap/R [1/T_2 -1/T_1 ]