Limiting Reagents Lab Essay

Problem What mass of precipitate will form when 1.69g of CuCl2.2H20 reacts with 1.31g of aluminium? font 3 Materials 150 mL beaker Erlenmeyer Flask 100ml Graduated Cylinder Funnel Scoopula Electronic Balance Stir rod Aluminum Foil CuCl2.2H20 Distilled WaterProcedureDay 1 Rinse beakerwith distilled water. book 1.69g of CuCl2.2H2O. Add to beaker and wreak 50mL of distilled water. Mass atomic number 13. Fold in 1/2 & coil loosely. Place in beaker and let seat overnight.Day 2 Pull out Aluminum and rinse into beaker Mass filter writing, put get wind on it Put paper in funnel and funnel into the Erlenmeyer flas. Pour in mixture. Rinse beaker triad times. Rinse funnel and paper twice. Remove Paper and let dry overnight.Day 3 Mass filter paperselective information Collection and touch on (DCP)Aspect 1 Recording Raw DataMass of CuCl2.2H2O 1.93gMass of Al ? (The massing of the aluminum was forgotten)Experimental mass of precipitate = .69gAspect 2 Processing Data2Al(s) + 3CuCl2.2H2O 3Cu(s) + 6H2O(l) + 2AlCl3(aq)m Al=1.93gM Al= 26.98 g/molm 3CuCl2.2H2o = 1.69 gM 3CuCl2.2H2o = 152.47 g/mol (Chem 20 Data Booklet)m Cu = ?n CuCl2.2H2O = 1.93g / 170.49 g/moln CuCl2.2H2O = .011320312 mol3 mol CuCl2.2H2O = 3 mols Cun Cu = .011320312 molm Cu = .011320312 mol x 63.55 g/molm Cu = .719g% yield = .69 / .719 = 96%Aspect 3Experimental mass of Cu(s) precipitate = .69gTheoretical mass of Cu (s) precipitate = .719g% yield = 96% coda and Evaluation (CE)Aspect 1 Conclusion The mass of precipitate that forms when 1.93g of CuCl2.2H20 reacts with 1.31g of aluminum is .69 g. The % yield was 96%. The massing of aluminum was forgotten but when another piece was massed and the numbers were worked out, it was shown that there was an excess of aluminum and that the CuCl2.2H2O was the limiting reagent.Aspect 2 Evaluate There were .029g of Cu precipitate less than expected. It is likely that some of the copper went into the Erlenmeyer or was stuck on the funnel. Despite thorough rinsing of the filter paper, some of the precipitate got through the filter paper and into the Erlenmeyer.Aspect 3 Improving Experimental Design Instead of one piece of filter paper, dickens pieces should be used. This would lead to less precipitate going into the Erlenmeyer. Also, the water in the Erlenmeyer could be re-filtered.