Your new supervisor at Barry Specialty Chemicals, LLC, Tim Smith, has just learned that yet another batch of labels has gone missing - he has become livid. You were supposed to have resolved the label problem after the last fiasco! Again, fortunately, the cases are marked with the bottling date. This time, the only analyses available for chemicals bottled on that date are NMR analyses. You have seven possible unlabeled chemicals to match with their 1H NMR spectrum before shipment:
methyl butanoate
benzaldehyde
- 1-chlorobutane
- 1-chloro-2-methylpropane
- butan-2-one
- propan-2-ol
- propanal
- Based on your knowledge of how NMR spectroscopy probes molecules, author a brief outline of how you would identify each of the unlabeled chemicals. Provide a drawing of each molecule with reasonable signal shifts and descriptions to complete your identification outline. Be specific. Also, identify anything that would stop you from making a unique, positive identification of any of the chemicals. You may also use your knowledge of other tests or chemistries to help ID these chemicals.
- 5.METHYL BUTANOATE
PROVIDE AN IDENTIFICATION SCHEME FOR METHYL BUTANOATE
INCLUDE A BRIEF OUTLINE OF HOW YOU WOULD IDENTIFY METHYL BUTANOATE
INSERT A DRAWING OF METHYL BUTANOATE AS WELL WITH REASONABLE SIGNAL SHIFTS AND DESCRIPTIONS. BE SPECIFIC. WHEN INSERTING THE IMAGE, RESIZE THE IMAGE AND USE THE IMAGE EDITING TOOLS (SELECT IMAGE AND CLICK ON RED BUTTON THAT APPEARS) TO CROP AND ROTATE THE IMAGE AS NEEDED.
YOU MAY ALSO USE YOUR KNOWLEDGE OF OTHER TESTS OR CHEMISTRIES TO HELP ID METHYL BUTANOATE.
ALSO, IDENTIFY ANYTHING THAT WOULD STOP YOU FROM MAKING A UNIQUE, POSITIVE IDENTIFICATION OF METHYL BUTANOATE
- BENZALDEHYDE
- PROVIDE AN IDENTIFICATION SCHEME FOR BENZALDEHYDE
- INCLUDE A BRIEF OUTLINE OF HOW YOU WOULD IDENTIFY BENZALDEHYDE
- INSERT A DRAWING OF BENZALDEHYDE AS WELL WITH REASONABLE SIGNAL SHIFTS AND DESCRIPTIONS. BE SPECIFIC. WHEN INSERTING THE IMAGE, RESIZE THE IMAGE AND USE THE IMAGE EDITING TOOLS (SELECT IMAGE AND CLICK ON RED BUTTON THAT APPEARS) TO CROP AND ROTATE THE IMAGE AS NEEDED.
YOU MAY ALSO USE YOUR KNOWLEDGE OF OTHER TESTS OR CHEMISTRIES TO HELP ID BENZALDEHYDE.
ALSO, IDENTIFY ANYTHING THAT WOULD STOP YOU FROM MAKING A UNIQUE, POSITIVE IDENTIFICATION OF BENZALDEHYDE.
1-CHLOROBUTANE
- PROVIDE AN IDENTIFICATION SCHEME FOR 1-CHLOROBUTANE
- INCLUDE A BRIEF OUTLINE OF HOW YOU WOULD IDENTIFY 1-CHLOROBUTANE
- INSERT A DRAWING OF 1-CHLOROBUTANE AS WELL WITH REASONABLE SIGNAL SHIFTS AND DESCRIPTIONS. BE SPECIFIC. WHEN INSERTING THE IMAGE, RESIZE THE IMAGE AND USE THE IMAGE EDITING TOOLS (SELECT IMAGE AND CLICK ON RED BUTTON THAT APPEARS) TO CROP AND ROTATE THE IMAGE AS NEEDED.
- YOU MAY ALSO USE YOUR KNOWLEDGE OF OTHER TESTS OR CHEMISTRIES TO HELP ID 1-CHLOROBUTANE.
ALSO, IDENTIFY ANYTHING THAT WOULD STOP YOU FROM MAKING A UNIQUE, POSITIVE IDENTIFICATION OF 1-CHLOROBUTANE.
1-CHLORO-2-METHYLPROPANE
PROVIDE AN IDENTIFICATION SCHEME FOR 1-CHLORO-2-METHYLPROPANE
- INCLUDE A BRIEF OUTLINE OF HOW YOU WOULD IDENTIFY 1-CHLORO-2-METHYLPROPANE
- INSERT A DRAWING OF 1-CHLORO-2-METHYLPROPANE AS WELL WITH REASONABLE SIGNAL SHIFTS AND DESCRIPTIONS. BE SPECIFIC. WHEN INSERTING THE IMAGE, RESIZE THE IMAGE AND USE THE IMAGE EDITING TOOLS (SELECT IMAGE AND CLICK ON RED BUTTON THAT APPEARS) TO CROP AND ROTATE THE IMAGE AS NEEDED.
- YOU MAY ALSO USE YOUR KNOWLEDGE OF OTHER TESTS OR CHEMISTRIES TO HELP ID 1-CHLORO-2-METHYLPROPANE.
- ALSO, IDENTIFY ANYTHING THAT WOULD STOP YOU FROM MAKING A UNIQUE, POSITIVE IDENTIFICATION OF 1-CHLORO-2-METHYLPROPANE.
BUTAN-2-ONE
PROVIDE AN IDENTIFICATION SCHEME FOR BUTAN-2-ONE
INCLUDE A BRIEF OUTLINE OF HOW YOU WOULD IDENTIFY BUTAN-2-ONE
- INSERT A DRAWING OF BUTAN-2-ONE AS WELL WITH REASONABLE SIGNAL SHIFTS AND DESCRIPTIONS. BE SPECIFIC. WHEN INSERTING THE IMAGE, RESIZE THE IMAGE AND USE THE IMAGE EDITING TOOLS (SELECT IMAGE AND CLICK ON RED BUTTON THAT APPEARS) TO CROP AND ROTATE THE IMAGE AS NEEDED.
- YOU MAY ALSO USE YOUR KNOWLEDGE OF OTHER TESTS OR CHEMISTRIES TO HELP ID BUTAN-2-ONE.
- ALSO, IDENTIFY ANYTHING THAT WOULD STOP YOU FROM MAKING A UNIQUE, POSITIVE IDENTIFICATION OF BUTAN-2-ONE.
- PROPAN-2-OL
PROVIDE AN IDENTIFICATION SCHEME FOR PROPAN-2-OL
INCLUDE A BRIEF OUTLINE OF HOW YOU WOULD IDENTIFY PROPAN-2-OL
INSERT A DRAWING OF PROPAN-2-OL AS WELL WITH REASONABLE SIGNAL SHIFTS AND DESCRIPTIONS. BE SPECIFIC. WHEN INSERTING THE IMAGE, RESIZE THE IMAGE AND USE THE IMAGE EDITING TOOLS (SELECT IMAGE AND CLICK ON RED BUTTON THAT APPEARS) TO CROP AND ROTATE THE IMAGE AS NEEDED.
- YOU MAY ALSO USE YOUR KNOWLEDGE OF OTHER TESTS OR CHEMISTRIES TO HELP ID PROPAN-2-OL.
- ALSO, IDENTIFY ANYTHING THAT WOULD STOP YOU FROM MAKING A UNIQUE, POSITIVE IDENTIFICATION OF PROPAN-2-OL.PROPANAL
PROVIDE AN IDENTIFICATION SCHEME FOR PROPANAL - INCLUDE A BRIEF OUTLINE OF HOW YOU WOULD IDENTIFY PROPANAL
- INSERT A DRAWING OF PROPANAL AS WELL WITH REASONABLE SIGNAL SHIFTS AND DESCRIPTIONS. BE SPECIFIC. WHEN INSERTING THE IMAGE, RESIZE THE IMAGE AND USE THE IMAGE EDITING TOOLS (SELECT IMAGE AND CLICK ON RED BUTTON THAT APPEARS) TO CROP AND ROTATE THE IMAGE AS NEEDED.
YOU MAY ALSO USE YOUR KNOWLEDGE OF OTHER TESTS OR CHEMISTRIES TO HELP ID PROPANAL.
ALSO, IDENTIFY ANYTHING THAT WOULD STOP YOU FROM MAKING A UNIQUE, POSITIVE IDENTIFICATION OF PROPANAL.
review the missing Label spectra, labeled A-J, and match them to each unlabeled chemical. Leave the box for an unlabeled chemical spectrum empty if you cannot provide a reasonable determination. Explain why the spectra belong to the chemical in the bottle. Did the spectra you picked to match your initial description? FiLL out a table with your NMR analysis for each chemical.
Post lab questions:
- 1. Were there any compounds that you could not positively ID based on the information you had available to you? Explain if needed.
- 2. Explain your thoughts on whether or not using solely NMR is a good method to make positive IDs of chemicals.
- 3. How would you use NMR to distinguish between bromomethane and iodomethane? Explain.
- When the spectra used in this lab were obtained, your colleague had the followng chemicals and equipment:
300 MHz NMR
NMR tubes
Test tubes
- DI water
- Disposable pipets
- Solvents: CHCl3, C6D12, and CDCl3
- CRC Handbook (reference)
Use this information to answer questions 4 and 5.
4. Is there a solvent listed above that is inappropriate for NMR? Explain.
5. Which solvent would you order if you determined that a sample required a more polar solvent than what was available when the samples were collected? Explain.
6. A common experiment in organic chemistry labs involves the dehydration of cyclohexanol (an alcohol) to form cyclohexene. Would NMR spectroscopy have helped in determining if your reaction was successful? Explain.
7. 7. Draw a representative NMR spectrum of acetic anhydride. Explain the number of signals.