The Determination of Boiling and Melting Points in an Organic Compound

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The Determination of Boiling Points and Melting Points Introduction: An unknown sample can be identified through certain methods, one of which would be identifying its boiling and melting points. The boiling point of a liquid is a physical characteristic of a chemical as is the melting point a solid. Distillation is the method that will be used in this experiment to identify an unknown liquid and solid. Objectives 1. Identify the unknowns by its melting and boiling points. 2. Learn to set up a proper distillation apparatus. Theory: Intermolecular forces play a large part in identifying unknowns when conducting a distillation experiment. The stronger the bond, the higher boiling and melting points will be. This is because it takes a greater amount of kinetic energy to break apart the molecules, allowing them to boil off. The strongest of these is called the hydrogen-bond. These types of bonds have a high electronegativity, making them very stable and more difficult to break. Therefore, the boiling points and melting points are greater because more energy (through heat) is needed to break the bonds. The van der Waal forces will also aid in the identification of an unknown. These forces are dipole-dipole and dispersion, the latter being the weakest of the intermolecular forces. Although not as strongly bonded as the hydrogen bond, the it takes a high amount of energy to break them apart, causing high melting and boiling points. Molecular weight influences how strong the intermolecular forces can be. This because as the molecular weight increases, the surface area increases as well, making it more difficult to break the molecules apart (creating a stronger bond and a higher boiling and melting point). Experimental: The distillation apparatus was assembled as per page 2 of this lab report. An unknown solid, sample B, was collected and placed into
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