Chemistry 14BLSpring 2005Chemistry 14BL Spring 2005 Report Guidelines for the Synthesis of Aspirin (Experiment 4a) All parts of this lab are conducted and reported individually. WEEK 1 Pre-lab Work (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) Recrystallization 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/ (II) Prelab Assignment Questions (Week 1) Complete the three questions under WEEK 1 on pages 55 and 56 of your manual (III) Introductory Report material (Week 1). Be sure to include - The title of the experiment and date. - A reference (i.e. complete reference of the experiment including title of the lab manual, author, edition and page number of the experiment in the manual etc.) Include any changes to the procedure that you know you will make. - A short introduction (Summarize in two or three sentences the goals of the first week of the assignment. Outline the kinds of techniques that you will use in this part of the assignment) - A brief flow chart summary of the key procedures to be carried out during the first week. - MSDS information for salicylic acid (reagent grade), sulfuric acid (concentrated), and acetic anhydride (reagent grade) - A data table to record your observations during the synthesis. You MUST record all the observations into your lab notebook during your lab sessions. You will NOT receive any credit for your lab technique if you only record the weight of the chemicals for this experiment. (III) Post-lab Work for Week 1: (This is an individual report) Observations: Keep an orderly record of your data and observations during the synthesis. (See pages 58 and 58 in your lab manual for the kinds of observations you should be recording.) Data Analysis: (MUST SHOW ALL WORK FOR FULL CREDIT) Calculate the theoretical moles of aspirin from your synthesis. Identify and explain which reagent is limiting. Calculate your % crude yield Calculate your % corrected crude yield (refer to the lab manual for equation)Conclusions: Summarize your results Compare % crude yield and % corrected crude yield. Explain why they are different or slightly different. What can you conclude about the % crude yield (especially if your % crude yield is greater than 100% or less than 50%)?Report Guidelines for the Analysis of Aspirin (Experiment 4b) All parts of this lab are conducted and reported individually. WEEK 2 Pre-lab Work (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) Melting Point Determination 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/ Note: Read pages 93 – 102 in “Techniques in Organic Chemistry by Mohrig and others” for concepts in melting point theory. (II) Prelab Assignment Questions (Week 2) Complete the three questions under WEEK 2 on page 56 of your manual (III) Introductory Report material (Week 2). Be sure to include - The title of the experiment and date. - A reference (i.e. complete reference of the experiment including title of the lab manual, author, edition and page number of the experiment in the manual etc.) Include any changes to the procedure that you know you will make. - A short introduction (Summarize in two or three sentences the goals of the two analyses (titration and melting point determination) that you will be conducting. Outline the kinds of techniques that you will use in this part of the assignment) - A brief flow chart summary of the key procedures to be carried out during these analyses. - MSDS information for aspirin. - Data tables to record your observations during the titrations and the melting point determination. You MUST record all the observations into your lab notebook during your lab sessions. You will NOT receive any credit for your lab technique if you only record the weight of the chemicals for this experiment. (III) Post-lab Work for Week 2: (This is an individual report) Data and Observations (see p.59 under Analyses): - Keep an orderly record of your data. Make sure that data tables have appropriate titles and labels Data Analysis (SHOW ALL YOUR WORK) - Calculate the % recrystallized yield - Calculate the average % purity from all the trials of your titrations. Error Analysis (SHOW ALL YOUR WORK): - Calculate the % inherent error in the % purity for ONE of your trials. Identify each term in the error analysis. Conclusions: - Summarize the results from both week 1 and week 2- Based on the value of the experimental melting point (as compared to literature value), what can you conclude in terms of the purity of the product? Explain. - If your % purity is greater than 100%, explain why. If your % purity is less than 50%, explain
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