Cyclohexane Lab Report

Purpose

The purpose of the experiment was to determine the molar mass of unknown solute number 1. This was done by using colligative properties of solutions specifically, freezing point depression. Colligative properties depend on the number of molecules that are present in the solution rather than the nature of the molecules [1]. This fact is useful because knowing this allows one to use the properties of the number of molecule in the solution without needing to worry too much about the nature of the molecules. Using this knowledge, the experiment consisted of freezing cyclohexane over 4 trials, 3 trials involved increasing amount of salt while the first was pure cyclohexane. From the data collected from freezing the solutions one can apply colligative properties to figure out the average molar mass of the unknown solute number 1.
∆T=m K_fp [1]
The main equation used, where ∆T is equal to the difference in freezing temperature for the pure solvent and solution, m is equal to molality and Kfp is equal to the freezing point constant of cyclohexane.

Experimental Method

Ice bath was prepared with ice and salt, in one 400 mL beaker placed in a larger 600 mL beaker. Approximately 12 mL of cyclohexane was put into a test tube and measured to be 9.09g. The test tube was placed in the ice bath and the temperature was measured with a thermometer in intervals of two seconds. The recording stopped once the stirring rod could not move anymore and the temperature was constant for 10