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Title: Limiting Reactant LabDate: October 26th, 2020Name: Mr. ScullyResearch Question: To What extent does stoichiometry predict the mass of product that will be produced in a single displacement reaction?Purpose: To precipitate and collect a mass of silver metal which will allow for quantitative analysis and comparison of the theoretical and actual yields of the silver metal product. Cu (s) + 2 AgNO3 (aq) → Cu(NO3)2 (aq) + 2 Ag (s)Data:Chemical materialMass (grams) ± 0.001Copper metal7.462Silver nitrate5.882Filter paper1.449Filter paper and silver4.567Copper remaining after reaction6.210Qualitative Data:Day 1-The starting copper wire appeared to have an orange-red luster.-Silver nitrate appeared as a white crystalline powder which formed a clear colorless solution when added to water. -The starting copper wire was completely submerged in solution prior to allowing the reaction to sit for the night. -A slight white coating could be observed shortly after the copper was placed in the silver nitrate solution.Day 2-The copper wire was covered in shiny crystals with a silver metallic luster. -The solution had shifted to a light blue in color (suggesting copper ions in solution).-Some silver metal was lost during the transfer from the reaction flask to the filter. -The luster of the silver increased when washed with Nitric acid.-Silver particles were observed in the filtrate (wash) after the filtration process was complete. Day 3 -The dry product appears to have some copper residue remaining-Slight blue/green discoloration on filter paper. Calculations:Limiting Reactant Determination7.463 g Ag x 1 mol Cu63.55 g Cux 2 mol AgNO31 mol Cu x 169.87 g AgNO31 mol AgNO3 = 39.892 g AgNO3 (Need)*We only have 5.882 g of AgNO3 so it is our limiting reactant.Theoretical yield of Silver metal5.882 g AgNO3 x 1 mol AgNO3169.87 g AgNO3 x 2 mol Ag2 mol AgNO3 x 107.87 g Ag1 mol Ag = 3.735 g AgActual yield of silver metalMass of filter paper with silver – Mass of blank filter paper4.567 g ± 0.001 g - 1.449 g ± 0.001 g = 3.118 g ± 0.002 g Calculation of Percent Yield for silver metal % yield = Actual Theoretical x 100%% yield = 3.118 g Ag3.735 g Ag x 100%% yield = 83.48 % for silver metal.Calculation for experimental error100% - 83.48% = 16.52% experimental errorTotal measurement uncertainty calculation for silver metal3.118 g Ag ± 0.002 gRelative uncertainty 0.002g3.118 g x 100% = 0.064% total measurement uncertainty.Conclusion: This experiment demonstrates the extent to which stoichiometry can predict the mass of a final product in a single displacement reaction. The results show the final mass of silver can be predicted with an accuracy of 83.48%. The result of this experiment suggest stoichiometry is only moderately accurate when it comes to predicting the mass of a product. Realistically, the experimental yield result for this experiment should be much higher. A loss of silver precipitate was observed during the filtration and collection procedures of the experiment. If the silver could be collected, it would serve to reduce the experimental error and give even greater alignment between the actual and theoretical values for the experiment. After considering the impact of measurement uncertainties in this experiment it becomes clear that random errors originating from the use of electronic balances only comprise 0.064% of the error in this experiment. The majority of the 16.52% experimental error is due to systematic errors. (Specific systematic errors appropriate to your personal lab experience can be identified here)A clear strength of this experimental approach is that it relies on the use of stoichiometry. This mathematical methodology is well accepted and highly appropriate for performing quantitative calculations involving matter in the field of chemistry. A weakness of this experiment was that the filter paper available had a pore size too large to retain the smallest of the silver particles formed during the reaction. This means silver was certain to be lost regardless of the care taken in handling the material during filtration and washing.The most obvious improvement would be to obtain filter paper with the appropriate pore size to ensure no loss of silver during the filtering and washing stages of the experiment. ................
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