Melting Point and Boiling Point of Organic Compounds
Sample Lab Report
for CHM 152
Name
Lab Partner(s)
Abstract:
The physical properties, including the boiling point, density, and refractive index were measured for unknown liquid #16. The infrared (IR) spectrum of the compound was also taken. Based on the data collected, it was determined that the compound was likely to be salicylaldehyde.
Introduction
The purpose of this experiment was to determine the identity of an unknown organic liquid by measuring some of its physical properties. The properties were then compared to those of known compound to make an identification. The properties determined included density, boiling point, refractive index, and important absorption bands in the infrared spectrum.
Experimental
Unknown number 16 was obtained for the experiment. The unknown was an oily, colorless liquid which had a strong fruity odor. Measurement of the properties was conducted over a period of two lab classes.
Density was determined by weighing an empty vial along with its cap. After recording the mass, exactly 1.0 mL of unknown was transferred to the vial using an automatic pipetting device. The vial was then quickly capped to minimize evaporation and weighed. The mass of 1.0 mL of liquid was calculated as the difference in the two weighings. This procedure was repeated two more times and the average of the three measurements was recorded as the density.
The boiling point was measured using a microscale device consisting of a capillary tube, a microcapillary tube and a melting point apparatus. The microcapillary tube was sealed on one end by rotating the end gently in a Bunsen burner flame until it was sealed. Care was taken to avoid overheating the tube which would cause it to bend. The larger capillary tube was heated gently in the flame on its sealed end. While still hot, its open end was dipped into the unknown liquid. As the tube cooled, a small amount of liquid was drawn into it. The liquid in the tube
for CHM 152
Name
Lab Partner(s)
Abstract:
The physical properties, including the boiling point, density, and refractive index were measured for unknown liquid #16. The infrared (IR) spectrum of the compound was also taken. Based on the data collected, it was determined that the compound was likely to be salicylaldehyde.
Introduction
The purpose of this experiment was to determine the identity of an unknown organic liquid by measuring some of its physical properties. The properties were then compared to those of known compound to make an identification. The properties determined included density, boiling point, refractive index, and important absorption bands in the infrared spectrum.
Experimental
Unknown number 16 was obtained for the experiment. The unknown was an oily, colorless liquid which had a strong fruity odor. Measurement of the properties was conducted over a period of two lab classes.
Density was determined by weighing an empty vial along with its cap. After recording the mass, exactly 1.0 mL of unknown was transferred to the vial using an automatic pipetting device. The vial was then quickly capped to minimize evaporation and weighed. The mass of 1.0 mL of liquid was calculated as the difference in the two weighings. This procedure was repeated two more times and the average of the three measurements was recorded as the density.
The boiling point was measured using a microscale device consisting of a capillary tube, a microcapillary tube and a melting point apparatus. The microcapillary tube was sealed on one end by rotating the end gently in a Bunsen burner flame until it was sealed. Care was taken to avoid overheating the tube which would cause it to bend. The larger capillary tube was heated gently in the flame on its sealed end. While still hot, its open end was dipped into the unknown liquid. As the tube cooled, a small amount of liquid was drawn into it. The liquid in the tube