CHEM 20L Must show all work for FULL creditCHEM 20L Fall 2006 Report Guideline for The Analysis of Acetic Acid Experiment Pre-lab report MUST be written in your lab notebook. Type written reports will NOT be accepted. (I) On-line Technique Videos For This Experiment Click on the title below to download the video (require Real Player) (1) Laboratory Safety (this video was shown on the first day of the lab) (2) Solution Preparation (3) Use of a Buret If you have trouble downloading the videos, go to the following Web site and click on the appropriate title to download the video. http://oid.ucla.edu/Webcast/Chemistry/ Guides for Writing Lab Reports On-line resources for acid-base chemistry (II) Pre-lab Report Guideline (Week 1 ONLY) IMPORTANT: Make sure that you follow the proper laboratory safety protocol (refer to the course syllabus) BEFORE going to the lab. A laboratory safety check will be conducted at the beginning of the lab. You will be dismissed from the laboratory if you do not have the proper safety protocol. Please also make sure that you show up to the lab on time. Any pre-lab reports that are NOT turned in within the first ten minutes of the lab section will not be accepted for grading. (i) Title (ii) Reference (iii) Introduction (iv) Procedures (flow chart format) (week 1 ONLY) (v) MSDS information (refer to the MSDS handout for details) The following chemicals will require you to use the MSDS database on the Web (refer to the MSDS handout for details on how to do the search): Acetic Acid (0.8 M); NaOH (2M) Note: Select the site that gives you the MSDS information closest to the concentration or grade listed above for each individual chemical. You should record the following MSDS information in your notebook for the chemicals listed above. Printouts directly from Web pages will NOT be accepted for grading. Important: Reference the site (i.e. write down the URL address) that you used for each of the chemical. (a) Product Name (b) Chemical Formula (c) Formula Weight (d) Melting Point; Boiling Point and Density (e) Health Hazard Data (summarize in your own words) (f) Spill and Disposal procedures (summarize in your own words)CHEM 20L Fall 2006 Report Guideline for The Analysis of Acetic Acid Experiment Pre-lab report MUST be written in your lab notebook. Type written reports will NOT be accepted. (II) Pre-lab Report Guideline (Continued) (vi) Pre-lab study questions (refer to page 68). Under WEEK 1 complete questions #1 ONLY Must show all work for FULL credit (vii) Data/observations (Use a NEW page for this) Set up tables but leave blank.CHEM 20L Fall 2006 Report Guideline for The Analysis of Acetic Acid Experiment Post-lab report must be written in the lab notebook with the exception of graphs. IMPORTANT: Refer to the lab schedule for the due date of this post-lab. This is an INDIVIDUAL report. (I) Data and Data Analysis (Must show all work for full credit) All your calculated values should have the correct units and number of significant figures. - Using EXCEL or other spreadsheet program, organize ALL the data that you collected during the experiment in table format (printouts of data tables from EXCEL are acceptable) - Your data table should include ALL the raw data (i.e. not just the ones you use to plot the graphs) as well as all the calculated values for the derivative graphs. Refer to the lecture guide for sample data. - Each data table should have a title - Label all data entries clearly - Calculate the concentration of the standard solution - Determine the equivalence point from the expanded first derivative graphs and calculate the concentration of the unknown vinegar solution. You MUST label the equivalence point clearly on your graphs. - Calculate the relative average deviation for the concentration of your vinegar solution - Using the full titration curve of the vinegar, determine the pH at half the volume required to reach the equivalence point. This corresponds to the pKa of the vinegar. Make sure you label the pKa clearly on your full titration graph. (II) Graphs (Use EXCEL to plot the titration graphs) If you completed 3 trials, you should have a total of SEVEN graphs. Refer to the lecture guide for the general plot of sample titration graphs. - EXPANDED first derivative graph and EXPANDED titration graph for EACH trial. Note: you should plot NO MORE than 2.00mL total for the EXPANDED graphs. This means that you will need to zoom in to the equivalence point region for the expanded graphs. - ONE full titration graph (pick the best trial) of your vinegar with standard base titration. You will use this graph to determine the pKa. Make sure you print EACH GRAPH ON A SEPARATE PIECE OF PAPER. CHECK THE GRIDLINES for appropriate scaling. For EXPANDED graphs, the MINOR GRID increments should be no more than 0.05mL. Your graphs should have: - correct scales and full use of paper - axes (Labeled with units) - appropriate titles and labels - determine the equivalence point volume from the expanded first derivative graph for EACH trial. - graphical determination of pKunknown(vinegar)CHEM 20L Fall 2006 Report Guideline for The Analysis of Acetic Acid Experiment Post-lab report must be written inside the lab notebook with the exception of graphs. IMPORTANT: Refer to the lab schedule for the due date of this post-lab. This is an INDIVIDUAL report. (III) Error Analysis - Calculate the % inherent error for ONE of your vinegar titrations. Show all your work and identify each term clearly in your calculations. - Calculate the % difference between the calculated concentration of your unknown vinegar solution with the 5% (w/v%) vinegar solution (see week 1 pre-lab question 1). (IV) Conclusion - summarize results - Comment on the % difference between the experimental vinegar concentration with that of a concentration of 5% (w/v%). Is the % difference with the limit of the inherent error? - Compare the relative average deviation of your trials with the inherent error. What can you conclude? - possible sources of systematic
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