Ashley DeSilva
Section 2
May 20, 2009

Title: Recrystalization of Benzoic Acid

Abstract:

Impure Benzoic Acid was recrystalized to form pure Benzoic acid. Heat and water was used as aides to make the reaction happen during a timely manner.

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Experimental: Using an Electric Balance (Ohaus Voyager, V1RR80) and weighing paper, .068 g of impure Benzoic acid was weighed out. The Benzoic acid was then put into a 50 mL Eurlenmeyer flask and placed on the Thermolyme. The solubility of .068 g of Benzoic acid is 1 mL of water. This was poured into the flask while being heated in order for the acid to dissolve. When all the Benzoic acid was dissolved, it was removed from the heat with a tongs and placed on the table to cool to room temperature. The moment room temperature was met, the flask and its contents was then placed into a bath of ice cubes. The cubes helped to form crystals at the bottom of the flask. Water was then poured into the flask and stirred with a spatula. Next, circular paper was put into the top of the filtervac which was used to filter out excess water. As the water was filtered out, crystals were left up top. The spatula was used again to scrape the crystals and they were placed in a tube to dry overnight. The crystals were hard the next day, but were few in number.

Table 1

Solubility % Recovery = Recovered x 100 Start
Temp C° g/L
0 1.7
25 3.4 .056 x 100 = 82%
99 68 .068

Results and Discussion:

A few pieces of Benzoic acid were obtained as crystals. The weight