CHEM 14BL Winter 2004Note: any plots that are generated from computer software will NOT be accepted for grading for this experimentCHEM 14BL Winter 2004 Report Guideline for Experiment #2 Pre-lab Report is due at the beginning of the lab section. Refer to the laboratory syllabus for the due date for both the pre-lab and post-lab report. Both pre-lab and post-lab reports MUST be written inside your LAB NOTEBOOK. The procedure for this experiment is provided as a handout (NOT THE ONE IN THE MANUAL). (I) Pre-lab Guideline (i) Title of the experiment (ii) 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. (iii) Short introduction (Summarize in a few sentences about the background and the goal of the experiment. Outline the kinds of technique that you will use in the experiment) (iv) Procedures (flowchart format) (v) Pre-lab study questions (MUST show ALL your work) (complete ONLY#1,2,4,5 & 6 on page 4 of the handouts) Note: For question 2, you may assume that for EACH dilution process, each piece of equipment can ONLY be used once and you can also assume that no combinations are allowed for the same kind of equipment (i.e. you don't need to worry about the combination of a 10-mL and a 5-mL pipet). (vi) MSDS information (refer to the MSDS handout on how to use this resource on-line) Look up the following properties for Brilliant Blue FCF Note: for this compound, use the CS ChemFinder Web site (refer to the MSDS handout for the Web address) You should record the following MSDS information in your notebook. (Printouts directly from the Web pages will NOT be accepted!!) (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) (vii) Data/observations (start a NEW page in your notebook for this section) Note: Start a NEW page in your notebook for this section. The previous material will be turned in at the beginning of the period; this page will be turned in at the end of the lab period (refer to item #10 on page 5 of the handouts)CHEM 14BL Winter 2004 Report Guideline for Experiment #2 Refer to the laboratory syllabus for the due date of the post-lab report. Post-lab report MUST be written inside your LAB NOTEBOOK. The procedure for this experiment is provided as a handout. Post-lab Guideline (This is a GROUP Report) (i.e. TURN IN ONLY ONE POST-LAB PER GROUP) Useful definitions for the report: w/v% is defined as weight (in grams) of solute/100 mL of solution ppm is defined as mg of solute/ L of solution ppb is defined as µg of solute / L of solution (A) Data & Data Analysis Write out the name of each group member on your report as well as the individual responsibility when performing the experiment and writing the report (i) Set up a data table with columns for wavelengths you collected for your spectrum and the absorbances for the solutions you collected. Fill in the experimental data on the data table. At this point, you will only have data entries for one row and one column of the data table. You will fill in the rest of the data table later on in the report. (ii) Description of the serial dilution procedure and rationale for the design of the dilution procedures (iii) Calculate the concentrations (only molarity , ppm and w/v%) for all the solutions based only on the procedures that you designed. (iv) The value for the molar extinction coefficient for the Brilliant Blue FCF is reported in the literature (at 620nm) as 1.38X105 M-1 cm-1. Using this value and the measured absorbances (at 620nm) you collected in the lab, calculate the experimental concentrations (M) for each of the 3 most diluted solutions. You may assume L=1cm. (B) Graphs Note: any plots that are generated from computer software will NOT be accepted for grading for this experiment (i) Using millimeter graph paper, plot a Beer’s law calibration curve (concentration (M) as x-axis and absorbance as y-axis) based only on the calculated concentrations and measured absorbance for the three most diluted solutions at 620nm. (ii) Using millimeter graph paper, plot the spectrum (use absorbance as y-axis and wavelengths as x-axis) for one of the diluted solutions that you chose to measure during the lab. Note: DO NOT use the papers inside your lab notebook to plot the graphs. You MUST use mm graph papers to plot the graphs. You can purchase the mm graph papers in the ASUCLA bookstore. If you have questions about the proper type of graph papers, check with your teaching assistant or the course instructor.CHEM 14BL Winter 2004 Report Guideline for Experiment #2 Refer to the laboratory syllabus for the due date of the post-lab report. Post-lab report MUST be written inside your LAB NOTEBOOK. The procedure for this experiment is provided as a handout. Post-lab Guideline (This is a GROUP Report) (i.e. TURN IN ONLY ONE POST-LAB PER GROUP) (C) Error Analysis (refer to example in lecture guide #1) (i) Calculate the % Inherent Error (molarity only) for the FINAL (i.e. the most diluted one) solution that you prepared (Must show all work for full credit) Note: Absolute errors for all the lab equipment are listed on p.27 of the manual. (ii) Calculate the % difference between the calculated concentrations (part (iii) under Data and Data Analysis) and the measured values (part (iv) under Data and Data Analysis) for the three most diluted solutions at 620nm. (D) Complete all the items listed under “Discussions and Extrapolation” (refer to page 7 of the handout) (E) Complete all the items listed under ”Practical Considerations” (refer to page 8 of the handout) (F) Conclusions - Summarize data - Explain the effect of different wavelengths on the Beer’s law calibration graph (i.e. the one with absorbances and
View Full Document
Unlocking...