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7.Uv active compounds must possess a certain degree of conjugation, most commonly aromatic compounds.
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7. What type of compounds are visible with UV light? 8. With a polar stationary phase...
2. What are the phases involved in TLC? 3. What is coated on the TLC plate?...
2. What are the phases involved in TLC? 3. What is coated on the TLC plate? 4. What is the purpose of lining the wall of the TLC chamber with paper? 5. Why is it important to use a small amount of the mobile phase? 6. Why should you remove the TLC plate before the mobile phase reaches the top? 7. What type of compounds are visible with UV light? 8. With a polar stationary phase and non-polar mobile phase,...
1. What is the purpose of Thin-Layer Chromatography (TLC)? 2. What are the phases involved in...
1. What is the purpose of Thin-Layer Chromatography (TLC)? 2. What are the phases involved in TLC? 3. What is coated on the TLC plate? 4. What is the purpose of lining the wall of the TLC chamber with paper? 5. Why is it important to use a small amount of the mobile phase? 6. Why should you remove the TLC plate before the mobile phase reaches the top? 7. What type of compounds are visible with UV light? 8....
A type of chromatography known as reverse phase chromatography uses a non-polar stationary phase instead of...
A type of chromatography known as reverse phase chromatography uses a non-polar stationary phase instead of a polar stationary phase. How do you predict this will alter Rf values of the molecules shown above? Explain. This is a qeustion for the Chromatograph lab.
7. Given a non-polar stationary phase C18 (reverse phase) and a slightly polar mobile phase (15%...
7. Given a non-polar stationary phase C18 (reverse phase) and a slightly polar mobile phase (15% water 85% acetonitrile) predict the order of elution for the following compounds (with 1 being the fastest and 4 being the slowest) (6 pts) Methanol CH OH 1-florobutane CH CH CH2CH2F Butanol CH,CH CHCHOH Cyclohexane CoH12 Briefly justify how you made your choice(s) Now increase the polarity of the mobile phase to 85% water and 15 % acetonitrile. Explain the relative shifts in retention...
Ok, so what would happen if you are working with TLC and have a polar stationary...
Ok, so what would happen if you are working with TLC and have a polar stationary phase (silica) and a mobile phase ( polar eluting solution) and you spot a nonpolar compound? Would the Rf values be greater than in a nonpolar mobile phase? I know in general if you are using TLC with polar silica and spot a nonpolar compound the nonpolar compound travels further (higher Rf values) because its chemical structure is different than the stationary phase compared...
14. The chromatogram below was prepared using HPL.C with a polar stationary phase and OCH CH:NH2),...
14. The chromatogram below was prepared using HPL.C with a polar stationary phase and OCH CH:NH2), and pentanol (CsHiOH) polar mobile phase. (a) If the compounds in the sample were octanol (CsHi-OH), benzene (CHo), ethanolamine (H ( and please correlate the numbered peaks below with the compounds. (b) Please describe how you might improve the resolution of compounds 2 and 3 without changing the stationary phase. (8 points) 0.8 s 0.4 03 0.2 0.1 10 12 16 18 20 Time...
Using a nonpolar stationary phase and a mobile phase consisting of a 50:50 mixture of aqueous...
Using a nonpolar stationary phase and a mobile phase consisting of a 50:50 mixture of aqueous acetic acid and methanol, rank the following compounds in order of elution off of a HPLC column: Acetaminophen, caffeine, aspirin and benzoic acid
Huie Turva polar better with higher solvent stationary phase Study Problem: A mixture of organic compounds...
Huie Turva polar better with higher solvent stationary phase Study Problem: A mixture of organic compounds was analyzed by TLC using different solvent mixtures as mobile pha and the results are presented in the diagram below. Compare the TLC plates A-D with the one on the left and answer th questions: a) How is the polarity of the mobile phase used to TLC plate A comparative with plate on the left? b) How are the Ri's value on the plate...
Please draw a thin chromatography plate with the following terms labelled 1. Origin 2. Stationary Phase...
Please draw a thin chromatography plate with the following
terms labelled
1. Origin 2. Stationary Phase 3. Mobile Phase 4. Solvent Front 5. Component "spot" 6. Rf value 7. Development 8. Visualization of spots Define questions 9 and 10 9. What is meant by differential partitioning between stationary and mobile phase? 10. What is the recommended procedure for cleaning a TLC spotting capillary?
Which of the following compounds absorbs the shortest wavelength of UV visible light? О а Oь...
Which of the following compounds absorbs the shortest wavelength of UV visible light? О а Oь О с (E)-2-butene (Z)-2-butene butane (Z)-1,3-hexadiene O d o e (E)-1,3,5-hexatriene
2. What are the phases involved in TLC? 3. What is coated on the TLC plate? 4. What is the purpose of lining the wall of the TLC chamber with paper? 5. Why is it important to use a small amount of the mobile phase? 6. Why should you remove the TLC plate before the mobile phase reaches the top? 7. What type of compounds are visible with UV light? 8. With a polar stationary phase and non-polar mobile phase,...
1. What is the purpose of Thin-Layer Chromatography (TLC)? 2. What are the phases involved in TLC? 3. What is coated on the TLC plate? 4. What is the purpose of lining the wall of the TLC chamber with paper? 5. Why is it important to use a small amount of the mobile phase? 6. Why should you remove the TLC plate before the mobile phase reaches the top? 7. What type of compounds are visible with UV light? 8....
7. Given a non-polar stationary phase C18 (reverse phase) and a slightly polar mobile phase (15% water 85% acetonitrile) predict the order of elution for the following compounds (with 1 being the fastest and 4 being the slowest) (6 pts) Methanol CH OH 1-florobutane CH CH CH2CH2F Butanol CH,CH CHCHOH Cyclohexane CoH12 Briefly justify how you made your choice(s) Now increase the polarity of the mobile phase to 85% water and 15 % acetonitrile. Explain the relative shifts in retention...
14. The chromatogram below was prepared using HPL.C with a polar stationary phase and OCH CH:NH2), and pentanol (CsHiOH) polar mobile phase. (a) If the compounds in the sample were octanol (CsHi-OH), benzene (CHo), ethanolamine (H ( and please correlate the numbered peaks below with the compounds. (b) Please describe how you might improve the resolution of compounds 2 and 3 without changing the stationary phase. (8 points) 0.8 s 0.4 03 0.2 0.1 10 12 16 18 20 Time...
Huie Turva polar better with higher solvent stationary phase Study Problem: A mixture of organic compounds was analyzed by TLC using different solvent mixtures as mobile pha and the results are presented in the diagram below. Compare the TLC plates A-D with the one on the left and answer th questions: a) How is the polarity of the mobile phase used to TLC plate A comparative with plate on the left? b) How are the Ri's value on the plate...
Please draw a thin chromatography plate with the following
terms labelled
1. Origin 2. Stationary Phase 3. Mobile Phase 4. Solvent Front 5. Component "spot" 6. Rf value 7. Development 8. Visualization of spots Define questions 9 and 10 9. What is meant by differential partitioning between stationary and mobile phase? 10. What is the recommended procedure for cleaning a TLC spotting capillary?
Which of the following compounds absorbs the shortest wavelength of UV visible light? О а Oь О с (E)-2-butene (Z)-2-butene butane (Z)-1,3-hexadiene O d o e (E)-1,3,5-hexatriene
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