Chemistry, 02.07.2019 18:50 madisynivy6

Astudent dissolved a sample in hexane, spotted it on to a tlc plate and eluted using ethyl acetate. after visualizing the tlc plate under a uv lamp, the student found their sample had two spots corresponding to rf values of 0.31 and 0.85. they ran the tlc plate again, this time dissolving the compound in dicholoroacetic acid and using ethyl acetate as the eluent. what will be the rf values for each spot?

Answers: 1

Show answers

Answers

Answer from: brutalgitaffe

1) Consider the following silica gel TLC plate of compounds A, B, and C developed in hexanes:

Determine the Rf values of compounds A, B, and C run on a silica gel TLC plate using hexanes as the solvent.Which compound, A, B, or C, is the most polar?What would you expect to happen to the Rf values if you used acetone instead of hexanes as the eluting solvent?How would the Rf values change if eluted with hexanes using an alumina TLC plate?

Show answer

2) You are trying to determine a TLC solvent system which will separate the compounds X, Y, and Z. You ran the compounds on a TLC plate using hexanes/ethyl acetate 95:5 as the eluting solvent and obtained the chromatogram below. How could you change the solvent system to give better separation of these three compounds?

Show answer

3) After a rather lengthy organic chemistry synthesis procedure, a student ran the product of the reaction on a TLC plate and obtained the result below. What might he/she have done wrong, if anything?

Show answer

4) A student spots an unknown sample on a TLC plate. After developing in hexanes/ethyl acetate 50:50, he/she saw a single spot with an Rf of 0.55. Does this indicate that the unknown material is a pure compound? What can be done to verify the purity of the sample?

Show answer

5) Consider a sample that is a mixture composed of biphenyl, benzoic acid, and benzyl alcohol. The sample is spotted on a TLC plate and developed in a hexanes/ethyl acetate solvent mixture. Predict the relative Rf values for the three compounds in the sample.

Show answer

6) Plate A, below, represents the TLC chromatogram of a compound run in hexanes. The same compound was then spotted on a large TLC plate and again run in hexanes. Which TLC plate, B, C, or D, correctly represents how far the compound would run on the longer plate?

Show answer

Back to TLC

Original content © University of Colorado at Boulder, Department of Chemistry and Biochemistry.
The information on these pages is available for academic use without restriction.

Answer from: Quest

i think slash and

Answer from: Quest

elements make up everything, and they combine to make compounds.

the answer is c

Another question on Chemistry

Chemistry, 22.06.2019 00:00

For ai it's atomic number is 13 and it's mass number is 27 how many neutrons does it have

Answers: 1

Answer

Chemistry, 22.06.2019 02:30

What does the cell nucleus do or, how does it function?

Answers: 1

Answer

Chemistry, 22.06.2019 09:10

How have the greenhouse gasses increased from the year 2000 to 2018

Answers: 2

Answer

Chemistry, 22.06.2019 21:30

Plzz a sample of table sugar (sucrose, c12h22o11) has a mass of 7.801 g. ● a) calculate the number of moles of c12h22o11 in the sample b) calculate the number of moles of each element in c12h22o11 (number of moles of c, number of moles of h & number of moles of o) in the sample. (use your answer from part a as your starting point.) show your work and highlight your final answer. calculate the number of atoms of each element in c12h22o11 (number of atoms of c, number of atoms of h & number of atoms of o) in the sample. (use your answers from part b as your starting for each element.) show your work and highlight your final answer.

Answers: 1

Answer

You know the right answer?

Astudent dissolved a sample in hexane, spotted it on to a tlc plate and eluted using ethyl acetate....

Questions