Llab

Determining the Percentage Yield of a Chemical Reaction Name: Whitby Phuong Teacher: Ms. Li Course Code: SCH-3U1 Introduction Experiments carried out in real life may differ from the results based on theory. Reasons may include incontrollable work environments, competing reactions (where other reactions may occur at the same time as the principle reaction, the experimental design and techniques, and also due to impure reactants, since theoretical yield assumes that reactants are pure. (SCH-3U1 chemistry notes, Ms. Li) This lab is to identify the results that are determined by doing real life experiments, and compare the data based on theoretical results, which is then used to determine the percentage yield, or the accuracy of the real life experiment. In this lab, we will be using copper chloride dihydrate, and mixing it with water and iron, causing a single displacement reaction (Fe + CuCl2  FeCl2 + Cu). The purpose of this lab is to investigate the amount of copper that is displaced and compare the actual amount to the theoretical amount, and finding the percentage yield of copper using that information to determine its accuracy. (Chemistry 11. Canada: 2001.) Analysis Fe + CuCl2  FeCl2 + Cu {draw:frame} A. Using the mass of the iron (steel wool) you used, calculate the theoretical yield of the copper, in grams. Amount of steel wool used: 1.004 grams MFe= 55.845g/mol nFe= 1.004 grams/55.845 nFe= 0.01798 mol of Fe ∴ The percentage yield of copper is 5.071g by theory. B. How does the mass of the copper you collected compared with the expected theoretical yield? The amount of copper collected after evaporating the waste water was 1.183 grams, compared to the amount of copper theoretically that is supposed to be produced, which is 1.142g. The amount of copper tends to weigh slightly more than it is intentionally, by a difference of 0.041 grams heavier. Amount of CuCl2 · 2H2O used: 5.00 g MCuCl2 · 2H2O = 170.45g/mol MCuCl2= 134.45g/mol