DRAFT: This module has unpublished changes.

Question:  How do intermolecular interactions affect physical properties?

 

The purpose of this experiment is to determine the heat of vaporization of Ethanol and Acetone to find the strength of the intermolecular reactions occurring between the molecules of the solutions.  The ethanol molecule is much lighter and its boiling point is much higher than the boiling point of acetone because of the existing hydrogen bond between the ethanol molecules.  Many physical properties of substances are determined by the molecules interactions between each other.  DD forces exist between  water molecules and polar ethanol molecules for example.  The strength of the bonds between molecules is responsible for determining the melting and boiling points, and the vapor pressure  of a substance.  The greater the bond strength, the higher the melting/boiling point because the hydrogen bonds require more energy to be broken apart.  Greater bond strength also results in lower vapor pressure because less molecules will be able to escape into the gas phase since they are held together tightly by the strong bond.  The larger the size of the molecules, the more energy is required for them to be able to escape.  The greater amount of energy needed for molecules to escape from liquid phase to gas phase is reflected by the heat of vaporization.  Heat of vaporization is the energy required for a known amount of substance to escape from the liquid to gas phase.

DRAFT: This module has unpublished changes.