<p> CHEM 211 Laboratory Chemical Kinetics</p><p>Reference: General Chemistry Laboratory Experiments, Suzanne W Slayden, 1999, 3rd edition, Pages 137-143.</p><p>Purpose: The purpose of this experiment is to determine rate constant for a chemical reaction.</p><p>Procedure and Observations: Do preliminary calculations as instructed in the lab manual. Record all your data in your laboratory notebook as you proceed with the experiment.</p><p>Data: After you have measured the temperature and all the times and absorbances, enter your own data into the appropriate Web-based data entry form, using a computer in the lab. In your measurements and calculations, remember to pay attention to uncertainties and significant figures.</p><p>Results: Outside of class, retrieve your data in spreadsheet form (along with that of the entire class) from: http://chem.gmu.edu/results/. Then use Excel to calculate the densities of the various diluted solutions, stock solution and water.</p><p>Your lab report should include the following in addition to the pages from your lab notebook:  An Excel sheet “Raw Data” showing the raw data for the entire class (as downloaded).  A 2nd Excel sheet “Class Results” showing the calculated results for each student in the class – each in a separate row. The columns should include: o the elapsed times (in minutes) at which absorbances were measured o the ln(A) for each absorbance A, in the same order as the times o the slope and intercept for the ln(A) vs. time. Use the Excel functions =SLOPE(y-range, x-range) and =INTERCEPT(y-range, x-range). Note that the time values are the x-range and the ln(A) values the y-range. o the rate constant  A 3rd Excel sheet “My Results” showing your own results, only. There will be one row for each of your absorbance measurements. There should be two columns: o elapsed (minutes) o ln(A)  An Excel chart of ln(A) vs. time for your own data only, based on the “My Results” sheet described above. ln(A) should be on the y-axis and time on the x-axis. Include a linear regression fit to your points and show the equation of the line on the chart. Format your chart so that it looks like the Web example at: http://chem.gmu.edu/results/samples/Density_sample_charts/density.htm</p><p>Discussion: In your discussion section address the following points:  Why is it important to remove the sample from the spectrometer in between measurements?  Explain any deviations from linearity in your ln(A) vs. time plot.  What are the possible sources of error that could account for any difference in your value and the true rate constant value?  How consistent are the values of the rate constant obtained by the class? What is the standard deviation of the rate constants from the mean?</p>