Chelsea Woo Lab #1 2/9/11 Synthesis of Alum The objective of this lab was to carry out the experiment using procedures of weighing, vacuum filtration, and crystallization. Our goal was to be able to calculate the theoretical yield and percent yield of the synthesis reaction. We found our percent yield to be 93%, a fairly accurate finding because the closer to 100%, the more accurate your experiment was. Our preparation of the Aluminum sample was crucial to our accuracy. Cleaning the aluminum was the first important step. It was important to sandpaper the aluminum in order to remove oxidation from the surface of the metal. We then rinsed and cut the aluminum into very tiny pieces in order for the reaction to occur faster. After dissolving the pieces, making a solution, and using vacuum filtration, we formed crystals. To form these crystals, we slowly added H 2 SO 4 . This addition of H 2 SO 4 caused an exothermic reaction. It is exothermic because heat is flowing out of the system as it’s being added.
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This note was uploaded on 02/23/2011 for the course CHEM 150 taught by Professor Griffin during the Spring '11 term at Chapman University .