The Recrystallization of Benzoic Acid and the Physical Properties of Melting and Boiling Points (tot

Placed in the top of the flask which then was

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placed in the top of the flask which then was followed by the thermometer being placed within the adaptor so that the head of it is just below the arm that leads to the condenser. The condenser was then followed by another tube which would allow for the collected solution to drip down into a graduated cylinder. (Huston, Liu 37-38). The temperature of the collected solution was then recorded at about every 1.00 mL. Once the collected solution reached 25.00 mL the distillation process was stopped (Huston, Liu 38-39). The crude benzoic acid, which was placed aside in the lab before, was collected into capillary tube. The pure benzoic acid was collected within a separate capillary tube. The
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collected samples were then placed within a Melt Temp Apparatus. The dial was then placed on a low-medium voltage, and the capillary tubes were observed until the melting point of the crude and pure benzoic acid was reached (Huston, Liu 34-35). Results: The weight of the crystals at the beginning of the experiment was that of 2.08g. This was calculated by subtracting the weight of the crystals with the watch glass, 57.02g by the weight of just the watch glass which is 54.94g. Once the heated water was added to the crude benzoic acid crystals the resulting solution was clear and therefore, there was no need to use charcoal to decolorize the solution. The solution was allowed to cool after hot gravity filtration was performed. As the solution’s temperature cooled small crystals could be seen forming in the center of the solution. Then when the solution was put in ice to rapidly drop the temperature the whole solution itself crystalized. Vacuum filtration was performed and the pure crystals weighed 1.63g. This was calculated by subtracting the weight of the watch glass and the crystals 56.63g by the weight of the watch glass by itself 54.90. The percent recovery was then calculated to be 78.37%. During the distillation process the temperature of the collected solution at 1.00 mL was that of 54.3 degrees Celsius. At 2.01 mL the temperature was 54.9 degrees Celsius. In the range of 3.02 mL to 22.01 mL the temperature was that of a consistent 55.1 degrees Celsius. Then once
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the amount of the collected solution reached 23.02 mL the temperature raised to that of 55.3 degrees Celsius. Then at 24.00 mL and 25.01 mL of collected solution the temperature reached its’ peak of 56.0 degrees Celsius. The unknown solution C is believed to be that of Acetone which has a boiling point 56 degrees Celsius. During the Melt Temp Apparatus part of the experiment the two capillary tubes containing the crude and pure benzoic acid were observed until the melting points of the two crystal compounds were reached. The pure benzoic acid had an observed melting point range of 124.2 degrees Celsius to 125.4 degrees Celsius. The crude benzoic acid melting point consisted of a range from 125.1 degrees Celsius to 128.3 degrees Celsius. Discussion: The water that the benzoic acid was dissolved in was heated, because heat helps break the crystal lattice energy of the structure by adding the necessary energy to accomplish this task. The resulting solution was that of a clear. The amount of soluble impurities, meaning they have similar chemical properties and mix just as well as the target compound, was not in a great enough number to cause the solution to acquire a color change. The saturated solution was
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