4. The chromatogram below shows the separation of a mixture obtained by gas chromatography (GC) using a column temperature of 70C. The column used contains a polar stationary phase (polyethylene glycol) and the length is 15m. REPORT (all times in minutes) Peak Ret. Time Width @ Base tu 1.44 1 2.33 0.102 2 2.45 0.119 3 2.93 0.127 4 4.22 0.144 5 6.01 0.221 6 9.50 0.510 0 1 2 3 4 5 6 7 8 9 10 Time (min) The mixture separated contains the following six analytes: butanol, heptane, pentane, pentanol, octane and propanol. a. Explain the principle of separation taking place using GC. Predict the elution order of these compounds (assign them numbers 1-6) using the chromatographic conditions stated above. Justify your answer. [5pts] b. Calculate the resolution (Rs) and selectivity (a) factors for the two overlapping peaks. [4pts] c. Calculate the number of theoretical plates (N) and plate height (H) for Peak 4. [4pts] d. Suggest how improvements could be made to the chromatography to improve the separation. State the conditions you would use. Explain your answer. [3pts]

4. The chromatogram below shows the separation of a mixture obtained by gas chromatography (GC) using a column temperature of 70C. The column used contains a polar stationary phase (polyethylene glycol) and the length is 15m. REPORT (all times in minutes) Peak Ret. Time Width @ Base tu 1.44 1 2.33 0.102 2 2.45 0.119 3 2.93 0.127 4 4.22 0.144 5 6.01 0.221 6 9.50 0.510 0 1 2 3 4 5 6 7 8 9 10 Time (min) The mixture separated contains the following six analytes: butanol, heptane, pentane, pentanol, octane and propanol. a. Explain the principle of separation taking place using GC. Predict the elution order of these compounds (assign them numbers 1-6) using the chromatographic conditions stated above. Justify your answer. [5pts] b. Calculate the resolution (Rs) and selectivity (a) factors for the two overlapping peaks. [4pts] c. Calculate the number of theoretical plates (N) and plate height (H) for Peak 4. [4pts] d. Suggest how improvements could be made to the chromatography to improve the separation. State the conditions you would use. Explain your answer. [3pts]

Chemistry

10th Edition

ISBN:9781305957404

Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste

Chapter1: Chemical Foundations

Section: Chapter Questions

Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...

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