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Lab Report Limiting Reactant

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Limiting Reactant Lab
Abstract
The purpose of this lab was to use stoichiometry (fixed molar ratios) to determine quantitatively how Copper (II) Chloride and metallic aluminum react, known as an oxidation-reduction reaction. By varying the quantities of CuCl2H2O and Al and observing the reaction we were able to determine the limiting and excess reactants, and were also able to use stoichiometric calculations to determine the theoretical yield of Cu and then compare it to the actual yield of Cu to determine the percent yield of the reaction, which was found to be 22.5%. The percent yield of this experiment was less than desirable due to the fact that not enough Al was added to fully react all of the Cu. Using stoichiometry it was determined …show more content…

This experiment was designed to illustrate the relationship between quantities of reactants and the amount of product produced by a chemical reaction. When a chemical reaction occurs, there is usually a limiting reagent, which is the chemical that is totally consumed at the end of the chemical reaction, and the reagent that limits the amount of product that can be formed. The purpose of this lab was to determine which reactant was the limiting reagent and to see how much of the other reactant was used.
The reaction tested in this experiment was between Copper (II) Chloride and Aluminum metal. The principals of stoichiometry and limiting reagents were used to predict that amount of product that is produced when mixing two solutions to produce an insoluble product. We were able to determine this information by starting with a balanced chemical equation: 3CuCl2 2H2O +2Al  3Cu +2AlCl3 …show more content…

Using these concepts, in beaker 3, we were able to determine the exact amount Aluminum needed to react with 100% of the Copper present. During this experiment we used 0.707 g of CuCl22H2O to determine how much Aluminum is needed to react we use the equation below: As you can see from the equation above exactly 0.074 g of Aluminum is needed to fully react 0.707 g of Copper, however as you can see in table 1, 0.077 g of Aluminum was used. This can create a small amount of error due to the fact that it is extremely hard to measure an exact amount of Aluminum, although all the Copper was reacted in beaker 3, as could be seen by its clear solution with a small amount of grainy precipitate (Copper), Aluminum is in a small amount of excess, which could possibly affect the weight of the end product thus possibly causing error if the percent yield was

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