CHEM 142 Lab 2 Report
CHEM 142 Lab 2 Report CHEM 142
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This 4 page Class Notes was uploaded by Angel Lee on Saturday October 31, 2015. The Class Notes belongs to CHEM 142 at University of Washington taught by David Ginger in Fall 2015. Since its upload, it has received 173 views. For similar materials see General Chemistry in Chemistry at University of Washington.
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Date Created: 10/31/15
NAME QUIZ SECTION STUDENT ID LAB PARTNER Chem 142 Experiment 2 Stoichiometry I l Reaction of Hydrogen Peroxide and Bleach ll Reaction of Fe2 with 110 Phenanthroline Grading 55 pts total 45 pts for this template 10 pts for notebook pages Notebook pages PurposeMethod section complete Are they organized and legible Have you plotted your data as instructed Note ALL sections of this report MUST be typed With this and all future Excelbased reports make sure that the report prints correctly graphs tables and text boxes are not split across page breaks before you turn it in If you print it and it doesn39t look okay use the tools in Excel to adjust the page breaks and then reprint the report before submitting it By signing below you certify that you have not falsified data that you have not plagiarized any part of this lab report and that all calculations and responses other than the reporting of raw data are your own independent work Failure to sign this declaration will result in 5 points being deducted from your report score Signature DATA CALCULATIONS AND GRAPHS Part I Reaction of hydrogen peroxide and bleach Concentration of stock solutions 2pts Bleach NaOCl a 300 mm NaOCl Hydrogen Peroxide H202aq 6oo mm H202 Measurement Mass of 0500 mL 1 2 3 4 Type your calculation of the density of bleach using the mass data from measurement 1 2pts 0577 g Bleach 0500 mL Bleach 115 gmL Type your calculation of the average density of bleach using the mass data from all four measurements 0577 g Bleach 0534 g Bleach 0568 g Bleach 0541 g Bleach 2220 g Bleach 444 gmL 0500 mL Bleach 0500 mL Bleach 0500 mL Bleach 0500 mL Bleach 0500 mL Bleach 1pt mL of Oxygen mL of Bleach Grams of Peroxide Generated 4 245 350 480 570 715 795 790 800 Vo ume 1001 0102 175 Mass g 0111202 900 800 o 0 o 700 Hydrogen Peroxide is in excess 5 600 a o X 9 500 2 is g 40390 Hydrogen Peroxide is 3 the limiting reactant gt 300 200 100 00 0000 0500 1000 1500 2000 2500 3000 3500 4000 4500 Mass g of Hydrogen Peroxide Grams of H202 solution at the Eqv Point 344 9 1m Moles H202 at the Eqv Point 607503 moies Moles NaOCI at the Eqv Point 716E03 moles Stoichiometry moles H202moles NaOCI 0848 1 pts Type your calculation for the moles of H202 at the equivalence point 344 9 H202 solution 6 g of Hgg2 02064 g H202 1 mol HQ 607 10quot3 mol H202 g of H202 solution 21008 215999 g g H202 Type your calculation for the moles NaOCI at the equivalence point 4 mL NaOCL solution 444 gmL 178 g of NaOCI solution g of NaOCI 0533 g of NaOCI 1 mol NaOCI 716 1043 mol NaOCI g of NaOCI solution 2299 15999 3545 g NaOCI Part II lronll Phenanthroine Reaction Concentration of stock 110 phenanthroline solution 360E03 M Concentration of stock Fe2 solution 250E03 M Volume of stock 110 phenanthroline solution you obtained 5000 mL 4 pts 3 pts 4pt 1pt 1pt Total Volume of Absorbance vs mL Fe2 0300 Iron is in excess U 0250 iron is the limiting reactant 0200 5 pts Absorbance O 1 1 U1 0 0100 0050 0000 0 01 02 03 04 05 06 07 08 09 Volume of Fe added mL uL of Fel at the Equivalence Point 17o IHI 1pt Moles phen at the Eqv Point 360E06 moles Moles Ferquot at the Eqv Point 425E07 moles Stoichiometry moles phenmoles Fe2 847 1 pt Type your calculation of the moles of 110 phenanthroline that you transferred to the 50 mL volumetric flask 3 ts 36 10quot 3 M 1 mL 00036 mol L 0001 L 36 10A 6 mol 1 10 phenanthroline p Type your calculation for the moles Fe2 at the equivalence point 3 pts 25 10A3 M 017 mL 00025 mol L 000017 L 43 10quot7 mol ir0n Type your calculation for the ratio of moles of phen to moles of Fe2 1pt 36 10quot6 mol 110 phenanthroline 847 43 10quot7 mol ironl Results and Discussmn Part 1 The expected stoichiometry is 1 1 How does your result compare calculate the error between your mole ratio and the expected value Are you within 5 of this value 2 pts 0848 1000 100 152 My result has a percent error of 152 percent In order to be within 5 percent of the true value the measured 1000 stoichiometric ratio must be between 0950 and 1050 Because I am not within these values I am not within 5 percent of the true value 2 What is your biggest source of error in this part of the experiment 2 pts The biggest source of error in this part of the experiment was probably not having enough sample It the sample was larger the results could have come closer to the true value 3 On the basis of the stoichiometry above predict the other two products 02 was one of the products and write a balanced equation for the reaction between H202 and NaOCl 2 pts H202 NaOCl gt 02 NaCl H20 Part II 1 The expected stoichiometry is 3 phen1 Fe2 How does your result compare calculate the error between your mole ratio and the expected Are you within 5 of this value 2 pts 847 300 100 182 My result has a percent error of 182 percent In order to be within 5 percent of the true value the measured stoichiometric ratio must 300 between 285 and 315 However because the percent error is not within these values my result is not within 5 percent of the expected value 2 What is your biggest source of error in this part of the experiment 2 pts The biggest source of error in this part of the experiment is probably the way in which the experiment was conducted During the experime nt not enough time was alloted tor the phen solution to react with the Fe Another source of error for our results could have been the incorrect use of the digital pipet Laboratory Waste Evaluation 1 pt Laboratory waste is considered anything generated during an experiment that is disposed of down the sewer drain thrown in the garbage collected in a container for disposal by the UW Environmental Health amp Safety department or released into the environment Based on the written lab procedure and your actions during the lab list the identity and approximate amount mass or volume of waste that you generated while performing this experiment Hydrogen peroxide 60 mL Bleach 32 mL for experiment Bleach 4 mL for measuring density Oxygen gas 4745 mL Water 1 L 1 10 Phenanthroline 1 mL Deionized water 49 mL ron solution 06 mL Water 1 L