[Pharmaceutical Chemistry] Melting Point and Boiling Point Determination

2807 Words Oct 8th, 2013 12 Pages
The Melting Point and Boiling Point determination of Malic Acid and Ethyl Acetate
By: Sabrina Grace T. Aguinaldo, Jan Dominik C. Arceo, Faerie Carleen Lucile L. Almira
Department of Pharmaceutical Chemistry, College of Pharmacy
University of the Philippines Manila
The Health Sciences Center
Valenzuela Hall, Taft Avenue, corner Pedro Gil St. Ermita, Manila Philippines

Keywords:
Melting Point: temperature at which a solid changes state from solid to liquid at atmospheric pressure.
Boiling Point: temperature at which the liquid has a vapour pressure equals the pressure surrounding it.
Intermolecular forces: forces responsible for attraction or repulsion between neighboring particles.
Hydrogen bonding: electromagnetic attractive interaction
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Its molecular weight is 88.1 g/mol, and it is flammable. It forms a dipole-dipole attraction between molecules. This force is less strong than the H-bonding like malic acid but strong enough for it to be in the liquid state at room temperature. The temperature needed to overcome this force is the boiling point.

Figure 2. Chemical Structure of Ethyl Acetate
Retrieved from: http://toxipedia.org/display/toxipedia/Ethyl+Acetate

The experiment is achievable in a three-hour time frame seeing as the materials are readily available in a laboratory, however the limited Mel-temp (apparatus) available during the time the experiment was conducted proved to be a barrier to the time efficiency seeing as several groups had to take turns borrowing it.

MATERIALS AND METHODS:

We were asked to determine the melting point and boiling point of two reagents, namely, malic acid and ethyl acetate. Materials needed for this experiment were two beakers (250 mL) for the water bath and oil bath, a thermometer, rubber bands, three capillary tubes, a bulblet (5ml test tube), a paper clip or safety pin, wire gauze, forceps, a simple distillation apparatus which includes a distilling flask, iron stands, iron clamps, rubber tubing, a Liebig condenser, a receiving flask and cork stopper to properly seal the set-up.

Cooking oil and water were used as the liquids for the hot
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