Circle which, if any, of the following compounds would show up as dark spots under a UV lamp when spotted on a TLC plate that contains a fluorescent indicator:
Homework Answers
Hello there,
Actually,I depends upon the choice of your indicator.
The more conjugated the compound, more it will absorb uv-light...thus the circled choices have enough conjugation so that they are potentially strong absorbents of uv light that no light reaches the indicator and hence the concerned spots appear dark spots.
cheers
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Circle which, if any, of the following compounds would show up
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Rank the following compounds form most polar to most non-polar, amide, either carboxylic acid, hydrocarbon, and...
Rank the following compounds form most polar to most non-polar, amide, either carboxylic acid, hydrocarbon, and ketone. Which of these compounds is NOT UV active? Circle all that quality. March the spots to the compounds How would you fix this TLC plate? How would you fix this TLC plate?
Possible Quiz Questions 1 What two methods of visualizing spots on a TLC plate will you...
Possible Quiz Questions 1 What two methods of visualizing spots on a TLC plate will you use in this Give two reasons why would you predict that the elution solvents (hexanes or acetate) would not be visible under UV visualization? week's lab? ethyl 2. Define R 3. Calculate the R of the spot on the following TLC plate. 4. Which compound in each pair is predicted to have the higher Ri? a. CH3CH2CH2CH2OH and CH3CH2CH2CH28r b. CH3CH2CH2CH2OH and CH3CH2CH2CH2CH2CH2CH3 c....
I need help with my pre and post lab questions. The three compounds below were spotted...
I need help with my pre and post lab questions.
The three compounds below were spotted on a TLC plate and developed to give the TLC plate shown. Which compound corresponds to which spot? Calculate the Rf value for spot B in the TLC plate shown above. When using polarity to determine the relative rates at which organic compounds travel up the TLC plate, we are considering compounds of similar molecular weight. It should also be noted that Rf values...
4. Consider the following silica gel TLC plac or compounds A, B, and hexines: developed in...
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Place approximately 10 mg of each of the four reference compounds in labeled vials or 10 X 75-mm ...
can you solve this for me,
please
Place approximately 10 mg of each of the four reference compounds in labeled vials or 10 X 75-mm test tubes and dissolve the samples in a few drops of methanol. In a fifth tube place a quarter of an analgesic tablet and add 1 mL of methanol. Crush the tablet with a rod, stir well, and allow the insoluble material to settle. Note that aspirin is not stable in methanol, so fresh solutions...
D Question 14 3.5 ts What is the line of solvent that moves up the TLC...
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Which of the following compounds would you expect to have the lowest Rf value on a...
Which of the following compounds would you expect to have the lowest Rf value on a silica gel TLC plate developed with dichloromethane? O A. Naphthalene O B. Phenyl acetate OC Butyric acid QUESTION 3 Which of the following compounds would you expect to have the highest Rf value on a silica gel TLC plate developed with dichloromethane? O A 2-octanone O B. Acetic acid C. 1-butanol OD. decane E. acetaldehyde
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Which of the following compounds would have the lowest Rfvalue on a TLC plate? HO OH...
Which of the following compounds would have the lowest Rfvalue on a TLC plate? HO OH A. B. C. D. E.
Help with the chem question in the picture, 11-15. 230 C at 16 mmHg) at atmospheric...
Help with the chem question in
the picture, 11-15.
230 C at 16 mmHg) at atmospheric pressure 11. A mixture of compounds A and B was run on TLC using 10% ethyl ac- etate/90% hexanes, and the R, values of 0.05 and 0.12 were obtained. Is this optimal? How can the separation be improved? 12. A mixture ofphenol and cyclohexanol is run on a TLC plate using 30% ethyl sing a UV lamp. Does this mean acetate/70% hexanes. Only one...
Rank the following compounds form most polar to most non-polar, amide, either carboxylic acid, hydrocarbon, and ketone. Which of these compounds is NOT UV active? Circle all that quality. March the spots to the compounds How would you fix this TLC plate? How would you fix this TLC plate?
Possible Quiz Questions 1 What two methods of visualizing spots on a TLC plate will you use in this Give two reasons why would you predict that the elution solvents (hexanes or acetate) would not be visible under UV visualization? week's lab? ethyl 2. Define R 3. Calculate the R of the spot on the following TLC plate. 4. Which compound in each pair is predicted to have the higher Ri? a. CH3CH2CH2CH2OH and CH3CH2CH2CH28r b. CH3CH2CH2CH2OH and CH3CH2CH2CH2CH2CH2CH3 c....
I need help with my pre and post lab questions.
The three compounds below were spotted on a TLC plate and developed to give the TLC plate shown. Which compound corresponds to which spot? Calculate the Rf value for spot B in the TLC plate shown above. When using polarity to determine the relative rates at which organic compounds travel up the TLC plate, we are considering compounds of similar molecular weight. It should also be noted that Rf values...
4. Consider the following silica gel TLC plac or compounds A, B, and hexines: developed in Fo-o- og a) Determine the Rr values of compounds A, B, and C run on a silica gel TLC plate using hexanes as the solvent b) Which compound, A, B, or C. is the most polar? values if you used acetone instead c) What would you expect to happen to the of hexanes as the eluting solvent? 5) Consider a sample that is a...
can you solve this for me,
please
Place approximately 10 mg of each of the four reference compounds in labeled vials or 10 X 75-mm test tubes and dissolve the samples in a few drops of methanol. In a fifth tube place a quarter of an analgesic tablet and add 1 mL of methanol. Crush the tablet with a rod, stir well, and allow the insoluble material to settle. Note that aspirin is not stable in methanol, so fresh solutions...
D Question 14 3.5 ts What is the line of solvent that moves up the TLC plate referred to as? O Solvent front O Capillary front Resolving factor Chromatographic boundary Question 15 3.5 pts Most organic compouds are colorless or white. A UV lamp assists in seeing your separation on TLC plates by: Making the organic sample spots glow and leaving the stationary phase dark Making the stationary phase glow, leaving dark spots where your sample is located Showing how...
Which of the following compounds would you expect to have the lowest Rf value on a silica gel TLC plate developed with dichloromethane? O A. Naphthalene O B. Phenyl acetate OC Butyric acid QUESTION 3 Which of the following compounds would you expect to have the highest Rf value on a silica gel TLC plate developed with dichloromethane? O A 2-octanone O B. Acetic acid C. 1-butanol OD. decane E. acetaldehyde
8 (7 pts) Which of the following pieces of glassware is best used for the process known as gravity filtration? Circle the BEST answer. 9. (12 pts) Owing to their structural similarity, separation of mixtures of organic compounds (such as the isomers 2-t-butyl-, 3-t-butyl-, and 4-t-butylcyclohexene) often proves difficult. Silica gel chromatography, however, can be used with some success provided that sufficient silica gel is used to provide optimal separation. Consider the TLC plate pictured at right after developing and...
Which of the following compounds would have the lowest Rfvalue on a TLC plate? HO OH A. B. C. D. E.
Help with the chem question in
the picture, 11-15.
230 C at 16 mmHg) at atmospheric pressure 11. A mixture of compounds A and B was run on TLC using 10% ethyl ac- etate/90% hexanes, and the R, values of 0.05 and 0.12 were obtained. Is this optimal? How can the separation be improved? 12. A mixture ofphenol and cyclohexanol is run on a TLC plate using 30% ethyl sing a UV lamp. Does this mean acetate/70% hexanes. Only one...
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