Cyclohexane Lab Report
Experiment 14: Molar Mass of a Solid
Angela Parra
Laboratory Partner: Eugenia Jimenez
Chemistry 1310
Instructor: Dr. Gao
Laboratory Assistant: Lauren
February 7, 2015
Abstract: The purpose of this experiment is to determine the molar mass of an unknown solid. The freezing point of a solvent (Cyclohexane) was determined, and compare to the freezing point of Cyclohexane with the addition of two different concentration of unknown solid. The pure substance of Cyclohexane has defined physical properties. However, when a solute is added these properties are determined by the amount of solute added, also known as colligative properties. The temperature of the freezing point was lowered when the solid was added and it decreased as the concentration of the solid increased. The molality of the solute was determined, which was then used to calculate the molar mass of the solid for both trials. An average of the molar mass of …show more content…
The molar mass is determined by dissolving the unknown compound into a pure liquid with defined physical properties, in this case Cyclohexane. When dissolving a solute, it forms a homogeneous solution, in which the solvent of the solution physical properties are not longer defined, but depends on the amount of solute added. Whenever a substance is dissolved in a solvent, the vapor pressure decreases. When the vapor pressure decreases, it also lowers the boiling and freezing point of the solvent and increases the osmotic pressure. These four properties are known as the colligative properties, the magnitude of the changes depends on the amount of solute dissolve; the changes are directly proportional to each other. The higher the solute concentration, the higher the changes of vapor pressure, therefore, a lower freezing point. It is hypothesized that the freezing point temperature will decreased, if there is a higher concentration of the solid added to the
Angela Parra
Laboratory Partner: Eugenia Jimenez
Chemistry 1310
Instructor: Dr. Gao
Laboratory Assistant: Lauren
February 7, 2015
Abstract: The purpose of this experiment is to determine the molar mass of an unknown solid. The freezing point of a solvent (Cyclohexane) was determined, and compare to the freezing point of Cyclohexane with the addition of two different concentration of unknown solid. The pure substance of Cyclohexane has defined physical properties. However, when a solute is added these properties are determined by the amount of solute added, also known as colligative properties. The temperature of the freezing point was lowered when the solid was added and it decreased as the concentration of the solid increased. The molality of the solute was determined, which was then used to calculate the molar mass of the solid for both trials. An average of the molar mass of …show more content…
The molar mass is determined by dissolving the unknown compound into a pure liquid with defined physical properties, in this case Cyclohexane. When dissolving a solute, it forms a homogeneous solution, in which the solvent of the solution physical properties are not longer defined, but depends on the amount of solute added. Whenever a substance is dissolved in a solvent, the vapor pressure decreases. When the vapor pressure decreases, it also lowers the boiling and freezing point of the solvent and increases the osmotic pressure. These four properties are known as the colligative properties, the magnitude of the changes depends on the amount of solute dissolve; the changes are directly proportional to each other. The higher the solute concentration, the higher the changes of vapor pressure, therefore, a lower freezing point. It is hypothesized that the freezing point temperature will decreased, if there is a higher concentration of the solid added to the