Chemistry 30AL Assignment 13: Extraction of Caffeine Report Guideline, Assignments of Chemistry

Download Chemistry 30AL Assignment 13: Extraction of Caffeine Report Guideline and more Assignments Chemistry in PDF only on Docsity! Chemistry 30AL Winter 2002 Report Guideline for Assignment 13, Extraction of Caffeine The prelab is due at the beginning of the lab section. Refer to the laboratory syllabus for the due date of the postlab. Both the written prelab and postlab parts of the report are to be done individually. Prelab guideline: Preparation for lab (individual work; due at the beginning of the lab) The Landgrebe questions will be part of the final report. They are not required prior to the beginning of the assignment. Introductory material must include (a) Title of the experiment, date, etc (b) Reference to procedures. Include any changes to the procedure (Note: UV, IR, and MS analysis will be required; sublimation will not be required) (c) A brief description of the purpose of the assignment (d) A detailed flow chart of the procedure showing the location of the caffeine at each step in the procedure. (e) MSDS data for caffeine, Ca(OH)2 and 1-propanol. Include: Product Name, Chemical Formula, Formula Weight , Melting Point or Boiling Point and Density (if a liquid), Health Hazard Data (summarize in your own words), Spill and Disposal procedures (summarize in your own words) Data and Observations (due at the end of the lab period) Be sure to describe what the system looks like at each stage. Are there any temperature changes when you added reagents? Postlab Report Data Analysis Use equations to help explain any chemical reactions.or explain the phenomenon (physical changes) behind each of your other observations. Calculations: Calculate the % caffeine that you recovered from tea. Compare your % caffeine value to the reported value of caffeine content in tea leaves in Landgrebe (see page. 380 - 381). Explain any differences. Spectral analyses: Compare your experimental IR spectrum to the literature IR spectrum (provided) with the IR worksheets. What can you conclude about the purity of your product? Based on the data that you obtained with the Spartan program, and table 10.1 in Landgrebe, identify the main peaks in the spectrum. Mass Spectrum of caffeine: (i) identify the base peak. (ii) identify the molecular ion peak. (iii) is the molecular ion peak the same as the base peak in the spectrum? UV spectrum of caffeine. Calculate the molar extinction coefficient of caffeine at λmax 272 nm Conclusions: Summarize your results. Estimate and discuss sources of error that could give rise to the yield that you obtained and the differences between your spectra and the reference IR and MS. Complete the prelab questions assigned in Landgrebe