Vapor Pressure and Heat Evaporation Lab Report

Vapor Pressure and Heat of Vaporization Introduction: Evaporation is the process of a liquid becoming vaporized. When a liquid is placed into a confined space some of the liquids will evaporate. Evaporation of the liquid depends on the strength of the intermolecular forces that are between liquid molecules. During the evaporation process of the liquid, new 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 at some point will be 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. The relationship between the vapor pressure 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 heat vaporization, R is the universal gas constant, which is (8.31 J/mol∙K), T is the absolute, or Kelvin, temperature, and C is the constant that is not related to heat 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 purpose of this experiment is to determine the relationship between the pressure and temperature of the volatile liquids. The pressure will be measured in a sealed vessel 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 able to be calculated.
Materials:
To be able to complete this lab procedure, the materials that are needed is a Vernier computer interface, a Vernier Gas Pressure Sensor, temperature probe, rubber stopper assembly,