A student was given an unknown mixture andwas asked to determine its composition bythin layer chromatography using silica gel as astationary phase and a 50:50 mixture of ethylacetate:petroleum ether as the mobile phase.The unknown mixture could be composed ofcompounds A-E. The student ran one TLC platecontaining compounds A-E, and a second TLCplate of their unknown mixture. Calculate theR, values for all components identified in theseTLC analyses and use this data to determine thecomposition of the unknown mixture.-+-+-+-+-+-ABCDEUnk

I used a ruler to measure the distance as shown in my monitor.Distance travelled by solvent = 5.3 cm…

Answered: A student was given an unknown mixture…

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...

See similar textbooks

Similar questions

Explain how Thin Layer Chromatography allows for the separation of the components of a mixture on a TLC plate? Please include these words: equilibrium, stationary and mobile phase, nonpolar and polar analytes, affinitity...which analytes (polar/nonpolar) have greater affinity for stationary or mobile phase?
The write-up says “A C18-silica column is used in this experiment, a 0.46 x 15 cm column with 5-µm particles. Equilibrate the column with 20 empty column volumes of 0.010 M phosphate buffer (pH 7.2) at a flow rate of 1.2 mL/min before beginning chromatography.” Show the calculation for how much mobile phase you would use (volume) and how long it will take to equilibrate the column.
In a 1.10 m gas-liquid chromatographic column the following results were obtained: air, 18.0 s; methyl acetate, 1.98 min.; methyl propionate, 2.24 min; methyl n-butyrate, 7.93 min. The base widths of the last three peaks were: 0.19; 0.23 and 0.79 min, respectively. Calculate the theoretical number of plates and the plate height of each column.
The following data are for a GLC column: L= 35.5 cm, flow rate = 0.303 mL/min A chromatogram of a mixture of the following compounds provide the following data: (min) (min) Air 0.9 | Benzene 5.0 0.71 Toluene 7.9 0.82 Xylene 8.4 1.16 Calculate: a. The number of plates from each peak. b. The mean for N. C. The plate height H. From the data above, calculate the resolution for d. Benzene and toluene. e. Toluene and xylene. F. Benzene and xylene. g. The length of column required to achieve an average resolution of 4.50.
4 You were assigned to determine the concentration of an unknown starch solution. [This unknown is different from Dr. Ford's unknown.] So you prepared a cuvette by mixing 5 drops of your unknown starch solution + 5 drops of water +3 mL buffer + 1 drop of iodine. You used the same spectrophotometer Dr. Ford used to measure the absorbance of your unknown starch mixture and the absorbance was 0.127. What is the concentration (in micro-g starch/micro-L) of your unknown starch solution? Assume that 1 drop of the unknown out of starch solution = 40 micro-L. Give a numerical answer with 3 sig figs without any unit. Answer:
tras 12. A standard stock solution is diluted to generate three working standard solutions containing ethyl acetate (EA) at 50 ppm, 400 ppm, and 800 ppm. An internal standard, n-butanol (nB), is added so its concentration is 1500 ppm in each of the working standard solutions. The solutions are analyzed using GC- FID. The peak area data for the peak corresponding to ethyl acetate from the standard chromatograms 50 ppm (EA area = 5.05, nB area = 124.37) 400 ppm (EA area = 47.98, nB area = 125.31) 800 ppm (EA area = 98.21, nB area = 98.21, nB area = 130.63) The results for the linear regression analysis for the data set using Excel are: m = 0.7065, b = 0.002134 m = 1.4251, b = -0.003901 m = 1.4215, b = -0.003091 m = 0.7015, b = 0.002231
For quantitative analysis with gas chromatography: O the area of a peak reported by the instrument for a compound is proportional to the quantity of that compound. O the calculated response factor value for a compound is proportional to the quantity of that compound. O the retention time reported by the instrument for a compound is proportional to the quantity of that compound. O the peak height reported by the instrument for a compound is inversely proportional to the quantity of that compound. O the peak shape reported by the instrument for a compound is proportional to the quantity of that compound.
You must separate three different compounds with reversed phase HPLC. Compound 1 is an acid (pKa = 4.3), compound 2 is neutral compounds and compound 3 is a base (pKa = 9.6). As eluent, use 30/70 (v / v)% methanol / pH 3.0 formic acid buffer. The retention time and the top width at the base of the top for the three components are presented below. You can assume the dead time to 1.2 minutes in your calculations.Compound Retention time [minutes] Peak width [seconds] 1 10.1 282 5.0 143 6.1 17a) Calculate the efficiency (number of theoretical bases) for component 1.b) Calculate the selectivity and resolution between components 1 and 2.c) When you increase the pH of your eluent to pH 6, how will the retention be affected (increase, decreaseor unchanged) for the different associations (1, 2 and 3) ?, justify your answer.d) How retention factors are generally affected by an increase in the proportion organicallymobile phase solvents for reversed phase HPLC separations ?, justify your…
A mixture of three components is separated using paper chromatography, and each component is analyzed using absorption. With standards containing 100 ppm of each component run simultaneously, the following data were obtained: cmpd A, 0.72 absorbance; B, 0.55; C, 0.80. For the unknown mixture, the data obtined when run under identical conditions were as follows: cmpd A, .0.15 absorbance, B, 0.84; C, 0.75. a) Calculate the relative percentage composition of the unknown mixture. b) The distances traveled by the three components were 8.5, 6.3, and 5.5 cm, respectively. Sketch the appearance of the paper chromatogram. Label each spot. c) Calculate the Rf values if the solvent front is 18 cm.
Give the solution of question
Please don't provide handwritten solution ....
Consider the following chromatographic data for the separation of methylparaben from ethylparaben in a sunscreen sample. Compound Methylparaben Retention time, tr (min). Width at base of peak, Wb (min) 3.2 4.2 0.55 0.60 Ethylparaben A compound not retained by the column in this analysis had a tm of 0.75 minutes. The column used was a C18 column with a mobile phase mixture of 75% methanol and 25% water. Calculate the number of theoretical plates for ethylparaben.

SEE MORE QUESTIONS

Recommended textbooks for you

Chemistry

ISBN:

9781305957404

Author:

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

Publisher:

Cengage Learning

Chemistry

ISBN:

9781259911156

Author:

Raymond Chang Dr., Jason Overby Professor

Publisher:

McGraw-Hill Education

Principles of Instrumental Analysis

Chemistry

ISBN:

9781305577213

Author:

Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:

Cengage Learning

Chemistry

ISBN:

9781305957404

Author:

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

Publisher:

Cengage Learning

Chemistry

ISBN:

9781259911156

Author:

Raymond Chang Dr., Jason Overby Professor

Publisher:

McGraw-Hill Education

Principles of Instrumental Analysis

Chemistry

ISBN:

9781305577213

Author:

Douglas A. Skoog, F. James Holler, Stanley R. Crouch

Publisher:

Cengage Learning

Organic Chemistry

Chemistry

ISBN:

9780078021558

Author:

Janice Gorzynski Smith Dr.

Publisher:

McGraw-Hill Education

Chemistry: Principles and Reactions

Chemistry

ISBN:

9781305079373

Author:

William L. Masterton, Cecile N. Hurley

Publisher:

Cengage Learning

Elementary Principles of Chemical Processes, Bind…

Chemistry

ISBN:

9781118431221

Author:

Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard

Publisher:

WILEY

SEE MORE TEXTBOOKS