1. You set up a chemical reaction with two materials, but only one of which shows...
1. You set up a chemical reaction with two materials, but only one of which shows up by TLC (Compound A, Rf = 0.75). Your product is supposed to have an Rf of 0.5 in the same eluent. Draw three TLC plates that you expect to see at these times: 1) at beginning of reaction, 2) halfway through reaction, 3) when reaction is done. Try to keep the TLC plates no more than 5cm in height, and just label the spots as A and product, and be sure to indicate which time each one is representing.
2. Draw out the structures of diphenylamine and hydroquinone. Based on their structures (using silica as the absorbent), which compound would you expect to elute first (diphenylamine or hydroquinone) from a chromatography column? Which would have the lower Rf value (using silica as the absorbent)? Molecular dipoles are of NO RELEVANCE. Rather, pay attention to individual dipoles. Read this again please – the molecular dipole DOES NOT MATTER here. INDIVIDUAL dipoles determine the answer.
3. If you are running a TLC using hexanes as your eluent, which solvent(s) make sense to wash the jar with:
acetone or dichloromethane or ether or hexane or any solvent except water
Homework Answers
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1. You set up a chemical reaction with two materials, but only
one of which shows...
A student monitored the reaction progress of the reduction of 4-Nitrobenzaldehyde to 4-Nitrobenzyl alcohol using TLC....
A student monitored the reaction progress of the reduction of
4-Nitrobenzaldehyde to 4-Nitrobenzyl alcohol using TLC. 30% ethyl
acetate in petroleum ether was used as the elution solvent. TLC
plates available in the laboratory were coated with the common
absorbent silica gel (SiO2.xH2O) which
contains polar hydroxyl (OH-) groups.
c. The crude product moves slower
than the starting material with the mobile
phase in the TLC plate. Briefly
explain a possible reason for the
observation based on the chemical
structures...
can you please answer all 1. When you run a TLC of the reaction in ethyl...
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...
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...
Experiment Write Up Proposal You will write up a synthesis procedure for one reaction that could...
Experiment Write Up Proposal You will write up a synthesis procedure for one reaction that could be potentially run in a face- to-face Chem 2321 lab session. Your proposal will include an introduction and procedure. The procedure will include step-by-step instructions for running the reaction (including reaction monitoring), work-up. (product isolation and purification), and analysis (characterization). You will need to include sample calculations for percent yield and provide sample spectra analysis. You must upload your proposal as a single document...
Attached is the lab experiment. Here are the questions I need help with: 1. What is...
Attached is the lab experiment. Here are the questions I need
help with:
1. What is the purpose of each of the following steps in this
experiment?
a. Adding solid NaCl to the reaction mixture
b. Repeated washings with water, sat'd NAHCO3, and brine
c. the pipet column chromatography
2. Which compound, cyclohexanol or cyclohexanone will have a
higher Rf on a TLC plate?
3. What is the advantage of using sodium hypochlorite as an
oxidant over CrO3 or Na2Cr2O7...
1 - Provide a balanced equation for this reaction 2 - Provide a mechanism for the...
1 - Provide a balanced equation for this reaction
2 - Provide a mechanism for the transformation of cyclohexanol
into cyclohexanone
3 - Provide a flow chart for the workup procedure for isolating
cyclohexane from all the by-products, making sure to note in which
layer you expect to find your product in each extraction.
4 - Provide the theoretical yield of cyclohexane in this
experiment.
PROCEDURE OXIDATION OF CYCLOHEXANOL TO CYCLOHEXANONE Set up a water bath as the heat source...
What is the objective of this experiment? The reaction solvent for this experiment is xylene. What...
What is the objective of this experiment?
The reaction solvent for this experiment is xylene. What
property of this solvent makes it a better choice than toluene or
benzene?
Draw the orbitals involved in the 4+2 electrocyclization for
this reaction. Draw the structures of the reactants as best you
can. It may be appropriate to abbreviate the structure of
anthracene.
IR is not provided for this reaction product. Why is IR not
useful for monitoring the reaction or characterizing the...
Which method could be used to convert alkene 1 to alcohol 2? Please show the reaction...
Which method could be used to convert alkene 1 to alcohol 2?
Please show the reaction mechanism. Question number 6 is also
needed please.
Part 2 - Word problems (4 pts each) 5. Taxol (compound 3) used in the treatment of several kinds of cancer, especially breast cancer. It was discovered from the bark of the Pacific yew tree. Each yew tree contains only a very small quantity, enough for just one dose for one person, so chemists started to...
Need help, numbers 3-6 please show work. and fill out table of chemicals for all chemical...
Need help, numbers 3-6 please show work. and fill out table of
chemicals for all chemical used.
calculate mmol in the table as well show work please
and each of these must be listed in its own row. There are 10 column headings: IUPAC name OR common name, structure, CAS number (Chemical Abstract Service number) molecular mass, melting point (if applicable), boiling point (if applicable), solubility (in water, if applicable), density, amounts to be used in the experiment, and the...
QUESTIONS TO ANSWER: Prepare a table of all chemicals used with the structure and purpose of...
QUESTIONS TO ANSWER:
Prepare a table of all chemicals used with the structure and
purpose of each.
Calculate the theoretical yield by finding limiting reactant of
the experiment by converting reactants to product (remember to show
all calculations used)
Calculate the percent yield using the limiting reactant
Calculate the Rf for triphenylmethanol. If there are two dots,
determine which one is triphenylmethanol.. ( I did not provide
data. Please let me know how I Would do this if I did)...
A student monitored the reaction progress of the reduction of
4-Nitrobenzaldehyde to 4-Nitrobenzyl alcohol using TLC. 30% ethyl
acetate in petroleum ether was used as the elution solvent. TLC
plates available in the laboratory were coated with the common
absorbent silica gel (SiO2.xH2O) which
contains polar hydroxyl (OH-) groups.
c. The crude product moves slower
than the starting material with the mobile
phase in the TLC plate. Briefly
explain a possible reason for the
observation based on the chemical
structures...
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...
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...
Experiment Write Up Proposal You will write up a synthesis procedure for one reaction that could be potentially run in a face- to-face Chem 2321 lab session. Your proposal will include an introduction and procedure. The procedure will include step-by-step instructions for running the reaction (including reaction monitoring), work-up. (product isolation and purification), and analysis (characterization). You will need to include sample calculations for percent yield and provide sample spectra analysis. You must upload your proposal as a single document...
Attached is the lab experiment. Here are the questions I need
help with:
1. What is the purpose of each of the following steps in this
experiment?
a. Adding solid NaCl to the reaction mixture
b. Repeated washings with water, sat'd NAHCO3, and brine
c. the pipet column chromatography
2. Which compound, cyclohexanol or cyclohexanone will have a
higher Rf on a TLC plate?
3. What is the advantage of using sodium hypochlorite as an
oxidant over CrO3 or Na2Cr2O7...
1 - Provide a balanced equation for this reaction
2 - Provide a mechanism for the transformation of cyclohexanol
into cyclohexanone
3 - Provide a flow chart for the workup procedure for isolating
cyclohexane from all the by-products, making sure to note in which
layer you expect to find your product in each extraction.
4 - Provide the theoretical yield of cyclohexane in this
experiment.
PROCEDURE OXIDATION OF CYCLOHEXANOL TO CYCLOHEXANONE Set up a water bath as the heat source...
What is the objective of this experiment?
The reaction solvent for this experiment is xylene. What
property of this solvent makes it a better choice than toluene or
benzene?
Draw the orbitals involved in the 4+2 electrocyclization for
this reaction. Draw the structures of the reactants as best you
can. It may be appropriate to abbreviate the structure of
anthracene.
IR is not provided for this reaction product. Why is IR not
useful for monitoring the reaction or characterizing the...
Which method could be used to convert alkene 1 to alcohol 2?
Please show the reaction mechanism. Question number 6 is also
needed please.
Part 2 - Word problems (4 pts each) 5. Taxol (compound 3) used in the treatment of several kinds of cancer, especially breast cancer. It was discovered from the bark of the Pacific yew tree. Each yew tree contains only a very small quantity, enough for just one dose for one person, so chemists started to...
Need help, numbers 3-6 please show work. and fill out table of
chemicals for all chemical used.
calculate mmol in the table as well show work please
and each of these must be listed in its own row. There are 10 column headings: IUPAC name OR common name, structure, CAS number (Chemical Abstract Service number) molecular mass, melting point (if applicable), boiling point (if applicable), solubility (in water, if applicable), density, amounts to be used in the experiment, and the...
QUESTIONS TO ANSWER:
Prepare a table of all chemicals used with the structure and
purpose of each.
Calculate the theoretical yield by finding limiting reactant of
the experiment by converting reactants to product (remember to show
all calculations used)
Calculate the percent yield using the limiting reactant
Calculate the Rf for triphenylmethanol. If there are two dots,
determine which one is triphenylmethanol.. ( I did not provide
data. Please let me know how I Would do this if I did)...
Most questions answered within 3 hours.
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