The purpose of this experiment is to determine the molecular weight of a compound by measuring the freezing point. In order to perform this lab, the freezing point of a pure substance, lauric acid (dodecanoic acid), will be measured by first melting and then freezing it. The freezing point of a mixture of lauric acid and an unknown solute will also be measured, using the same melting and freezing process. As the solute is added to the solution, the freezing point of the resulting solution is lowered. Then, using the freezing point change, the formula weight of the solute can be calculated. The melted solvent and the melted solution must be cooled very slowly in order to obtain a cooling curve. As stated, the results of this lab will inevitably allow the determination of the molecular weight of the unknown solute.