In thin layer chromatography, why must 1mL of dichloromethane be added to a mixture of Lycopene and carotene after the d...
In thin layer chromatography, why must 1mL of dichloromethane be added to a mixture of Lycopene and carotene after the dichloromethane was removed using the rotary evaporator?
Homework Answers
After the complete removal of DCM from the mixture using rotary evaporator, 1 mL of Dichloromethane (DCM) is added to make the compounds soluble in order to spot in TLC plate for the separation ans isolation of the compounds.
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In thin layer chromatography, why must 1mL of dichloromethane be added to a mixture of Lycopene and carotene after the d...
Thin Layer Chromatography: One spot with an RF of .62 is observed after you develop the...
Thin Layer Chromatography: One spot with an RF of .62 is observed after you develop the TLC of a reaction mixture. Does this prove that you have only one product present? Explain.
11. Why should you use pencil instead of pen when marking on a thin layer chromatography...
11. Why should you use pencil instead of pen when marking on a thin layer chromatography plate? a. Pencil lead isn't as dark. b. The components of pen ink will separate along with your sample, while pencil lead will not. c. Pen ink will not mark on a TLC plate. d. Pen ink will undergo a chemical reaction with the solvent. 12. Which of the following is not a reason to use thin-layer chromatography? a. To determine the number of...
6. Why is it necessary to perform a thin layer chromatography (TLC) before carrying out the...
6. Why is it necessary to perform a thin layer chromatography (TLC) before carrying out the Column chromatography? (0.75 points)
Why is thin layer chromatography used to determine the purity of a sample when you could...
Why is thin layer chromatography used to determine the purity of a sample when you could use an IR spectrum? How does TLC confirm the purity?
2. The diagram below shows the results of a simple thin layer chromatography experiment. height reached...
2. The diagram below shows the results of a simple thin layer chromatography experiment. height reached by the solvent the "solvent font a) Describe briefly, but precisely, what you would have done in order to get to this stage. You can assume that you have been given a suitable thin layer chromatography plate. b) Why is there a cover on the beaker? c) In order to help identify the things in a chromatogram, you can measure the Rf value for...
2. An unknown compound was analyzed using thin layer chromatography, its constituted of two components (A...
2. An unknown compound was analyzed using thin layer chromatography, its constituted of two components (A and B) as shown in the TLC (Silica coated stationary phase; Chloroform and Ethyl acetate as mobile phase). The mixture was then loaded onto column with silica as the stationary phase and the same solvent system was used. (2 points) Column Chromatography TLC time A В Predict the order of elution of the compounds (A and B). which one would be eluted first/last and...
A chemist runs a thin–layer chromatography (TLC) plate and, after development, forgets to mark the solvent...
A chemist runs a thin–layer chromatography (TLC) plate and, after development, forgets to mark the solvent front. The chemist doesn\'t realize this until the solvent has evaporated. Assuming that accurate Rf values are needed, select the correct course of action for the chemist. a. Assume that the solvent front is at the top of the plate. b. Dip the plate in phosphomolybdic acid (PMA) and heat the plate with a heat gun. c. Run the TLC analysis of these samples...
Example 3. Consider a Thin layer chromatography experiment of compounds A, B, C and D using...
Example 3. Consider a Thin layer chromatography experiment of compounds A, B, C and D using 50:50 Acetone Ether showed four spots under UV light (3 points) a) Calculate the Rf values for all spots A, B and C-show your work b) Match spots A, B, C and D with the four compounds below? solvent front A С В Но Но ОН ОН
Laboratory Instructor STUDENT REPORT A. Data Sheet EXPERIMENT 28 Aspartame 1. Thin-layer chromatography Distance traveled by...
Laboratory Instructor STUDENT REPORT A. Data Sheet EXPERIMENT 28 Aspartame 1. Thin-layer chromatography Distance traveled by solvent (1) Substance Distance teweled DR value Calculations: 2. KMnO, test Observations 10 min. 15 min. Reaction? 5 min. Substance 1092 330 Exploring Chemistry 3. Cari nitrate test B. Reflective Exercises and phenylalanine columns on the 1. How many spots should be seen for each of the aspartic acid and price chromatogram? Why? 2. Referring to the chromatogram, what did you here and what...
4. a) In the reductive amination reaction why is the NaBH, only added 15 minutes after...
4. a) In the reductive amination reaction why is the NaBH, only added 15 minutes after the amine and the aldehyde have been mixed, and not right away? b) What is a rotary evaporator (Rotovap) used for? c) In the Williamson Ether Synthesis, why did we use a reflux assembly and not just boil the reactants in a beaker or flask? d) Would you expect the melting point of a crude product to be higher or lower than the melting...
6. Why is it necessary to perform a thin layer chromatography (TLC) before carrying out the Column chromatography? (0.75 points)
2. The diagram below shows the results of a simple thin layer chromatography experiment. height reached by the solvent the "solvent font a) Describe briefly, but precisely, what you would have done in order to get to this stage. You can assume that you have been given a suitable thin layer chromatography plate. b) Why is there a cover on the beaker? c) In order to help identify the things in a chromatogram, you can measure the Rf value for...
2. An unknown compound was analyzed using thin layer chromatography, its constituted of two components (A and B) as shown in the TLC (Silica coated stationary phase; Chloroform and Ethyl acetate as mobile phase). The mixture was then loaded onto column with silica as the stationary phase and the same solvent system was used. (2 points) Column Chromatography TLC time A В Predict the order of elution of the compounds (A and B). which one would be eluted first/last and...
Example 3. Consider a Thin layer chromatography experiment of compounds A, B, C and D using 50:50 Acetone Ether showed four spots under UV light (3 points) a) Calculate the Rf values for all spots A, B and C-show your work b) Match spots A, B, C and D with the four compounds below? solvent front A С В Но Но ОН ОН
Laboratory Instructor STUDENT REPORT A. Data Sheet EXPERIMENT 28 Aspartame 1. Thin-layer chromatography Distance traveled by solvent (1) Substance Distance teweled DR value Calculations: 2. KMnO, test Observations 10 min. 15 min. Reaction? 5 min. Substance 1092 330 Exploring Chemistry 3. Cari nitrate test B. Reflective Exercises and phenylalanine columns on the 1. How many spots should be seen for each of the aspartic acid and price chromatogram? Why? 2. Referring to the chromatogram, what did you here and what...
4. a) In the reductive amination reaction why is the NaBH, only added 15 minutes after the amine and the aldehyde have been mixed, and not right away? b) What is a rotary evaporator (Rotovap) used for? c) In the Williamson Ether Synthesis, why did we use a reflux assembly and not just boil the reactants in a beaker or flask? d) Would you expect the melting point of a crude product to be higher or lower than the melting...
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