Column chromatography was performed ona mixture containing compounds A, B and Cusing silica gel as a stationary phase and a50:50 mixture of ethyl acetate:petroleum etheras the mobile phase. Six individual fractionswere collected during the separation, andTLC analysis of the fractions provided thedata shown. Evaluate and explain whetherthis column was successful in separatingcompounds A, B and C. If the column was notsuccessful, suggest what changes could bemade to provide a successful separation of thismixture.1 2 3 4 5 6

The column chromatography conducted on a mixture containing compounds A, B, and C using silica gel…

Answered: Column chromatography was performed on…

Fundamentals Of Analytical Chemistry

9th Edition

ISBN:9781285640686

Author:Skoog

Publisher:Skoog

Chapter31: Introduction To Analytical Separations

Section: Chapter Questions

Problem 31.19QAP

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A method of quantitative determination of the concentration of constituentsof a sample analyzed by gas chromatography is area normalization. Thiscomplete elution of all sample constituents is required. Thearea of each peak is measured and corrected for the detector response to the diffe- renteseluatos. This correction involves dividing the area by an empiricalcorrection factorDetermined. The concen ration of the analyte is found from the ratio between itscorrected and the total corrected area of all peaks. For a chromatogram containing threerelative areas were determined as 16.4; 45,2; and 30.2, in the order ofincreased retention time. Calculate the percentage of each compound if therelative responses from the detector are 0.65, 0.73 and 0.85, respectively.
Researchers used gas chromatography to determine the % v/v methyl salicylate in rubbing alcohol [Van Atta, R. E.; Van Atta, R. L. J. Chem. Educ. 1980, 57, 230-231]. A set of standard additions was prepared by transferring 20.00 mL of rubbing alcohol to separate 25 - mL volumetric flasks and pipeting 0.00 mL, 0.20 mL, and 0.50 mL of methyl salicylate to the flasks. All three flasks were diluted to volume using isopropanol. Analysis of the three samples gave peak heights for methyl salicylate of 57.00 mm, 88.5 mm, and 132.5 mm, respectively. Determine the % v/v methyl salicylate in the rubbing alcohol.
Next, 2.00 mL of 9.63 mM S was added to 10.00 mL of a solution of unknown concentration of X, and the mixture was diluted to 25.0mL. Chromatographic analysis of this solution produced peak areas of 4822 for X and 4099 for S. What was the concentration of 5 (in mM) of the 25.0mL solution?
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49 3. In a preliminary experiment, a solution containing 0.083M X and 0.0666M S gave peak areas of A, = 423 and As = 347. In the analysis of an unknown sample, 10.0 ml of 0.146M S was added to 10,0 ml. of the unknown and the mixture was diluted to 25 ml. in a volumetric flask. Axin the mixture was 553 and As was 582. What is the concentration of X in the unknown?
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