3) What two methods of visualizing spots on the TLC plate will you use in this lab? Why would you predict that the...
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....
5. Two unknown samples are spotted next to each other on a TLC plate. Development of the plate with ethyl acetate and visualization using UV light gives the following data: Spot 1: Rp = 0.65 Spot 2: Rp = 0.63 These two Rf values are so close that the difference might be due to experimental error (you're still learning TLC and not yet an expert in the technique). Describe an experiment that can be run using the same developing solvent...
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...
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,...
Common solvents used in TLC analysis are hexane and ethyl acetate, the latter being more polar. A TLC has been performed on a mixture of two compounds. The solvent ran for 3 cm(plate length is 6cm) with 5% ethyl acetate in hexane. The two spots were not resolved, meaning they showed up too close to each other. What can you suggest to possible improve the results of the separation?
2. A solution containing a mixture of naphthalene, benzoic acid, and benzaldehyde is analyzed via TLC and GC. Use the structures and properties of the compounds to aid in answering the following questions. A. In the TLC experiment, the mixture is spotted on a silica TLC plate and eluted with a 1:1 mixture of hexanes and ethyl acetate. Three spots are observed on the plate, with Re values of 0.25, 0.58, and 0.74. Indicate which spot corresponds to which compound....
7. (4 pt.) What two methods were used to visualize the spots on the developed TLC plate?
can you please answer all 1. When you run a TLC of the reaction in ethyl acetate : hexanes 1:1, the plate below is produced. Give a solvent system that would be expected to produce greater separation and a BRIEF (8 words) justification about your choice. (5 points) 7 6 5 4 3 b. Calculate the R for the bottom spot. (5 points) c. Which compound on the TLC plate is the most polar? (5 points) 2. Why is it...
During the TLC plate you notice all of the spots remain on the baseline. What is the problem and how would you fix it?
1) Why do we use a mixture of ethyl acetate and hexanes as solvents in the synthesis of 5,6-endo-dicarboxylic anhydride? 2) What do the terms exo and endo refer to? 3) Why do we not do any TLC on the product in the synthesis of 5,6-endo-dicarboxylic anhydride?