Melting Point Lab

Introduction
The purpose of this lab was to observe physical properties determined by intermolecular attractive forces, such as boiling point, melting point, and solubility. During this lab the soulbility of solids were observed. While testing boiling and melting point, the solid changed to a liquid.. By using different solids, it took different times in order for the chemical to break down, due to different molecular structures. Another purpose of the lab is to identify unknown substances, a way to do this is by taking an unknown substance and comparing it to potential solids along with thier melting points. Once these are observe the liquid can now be obseerved. The melting point point experiment also determines the purity of the substance

The pure urea was a crystal, sugary like substance, with an off white color. The cinnamic acid was a powdery, yellowish color. Both the urea and cinnamic were crushed on top of a watch glass, so that the solid could melt accuratly. Five watch glasses were grabbed. On the first watch glass pure Urea was placed on it. The second contained pure cinnamic, while the third one contained 1:4 of cinnamic, and the fourth containing an 4:1 ratio of urea. The last watch glass had 1:1 ratio of both samples. Each sample was put into two seperate capillary. The capillaries were dropped down a long glass tube to help the sample drop to the bottom and be tightly compacted. Once the machine was preheated the two samples of pure urea was placed inside of the machine. Once placed in the machine, the sample was watched to observe the melting point. The melting point was noted as soon as the first drop of liquid appeared until the crystal completely

139 mL is required to dissolve 25 grams of phtalic acid. Once cooled there would be 24.3 grams of phthalic acid left.
Activated carbon should be added to absorb high moleculat weight impurities.
It is not good to use a large quantity of activated charcoal because it will absorb some of the product, which could decrease the yield.
A mixture of solvent is used when the solvent does not have the wanted properties of rendering the soluble when how and insoluble when cold.
Suction filteration causes crystals to clog the funnel, which is why gravity filtration is prefered.
Fluted filter paper is used becuae it has a larger surface area making it easier for solvent to flow.
Stemless funnels are used because the long-stem funnels will cool which will cause clogging of thr steam due to the crystals.
Vacuum filtration is more effective for removing solvsent from the crystals than the gravity filtration. Wood applicator sticks should not be used to carry out chemical reactions because it will conraminate products.
Beakers should not be used during recrystallization because the beaker is too wide, allowing the solvent to