Problem set #2 (Meeting 2)

ATTN: answers to the below questions are due at the start of meeting 2; these answers should be part of your pre-lab write-up.

1. What is the function of the phosphoric acid in this experiment?

2. What is the expected alkene product formed from the dehydration of the following alcohols? Show major products only. help

3. The reaction of alkenes with bromine is used as a qualitative test in this experiment. Which product is formed in this reaction? How do you explain its stereochemistry?

4. As discussed in the lecture, the elimination reaction underlies an equilibrium. How is the experimental yield for the cyclohexene optimize in this reaction?

5. What are the most important changes in the IR spectrum going from cyclohexanol to cyclohexene (functional groups and wavenumbers)?

6. How do you know that you added enough drying agent?

7. Why is it important that the reaction mixture is homogeneous in the benzoin condensation?

8. Using PC Spartan 2002 at the Science Learning Center (4th Floor Young Hall) do the following:

a. Do the following calculations for the alkenes that you drew in meeting 1.

b. Select Calculations from the Setup menu.

The following window should appear. Select the options shown.

Verify that the Charge is Neutral and Multiplicity is Singlet. Click OK.

Select Submit from Setup menu.

Then click OK to exit dialog. Close the previous window.

Select Submit from Setup menu. When the calculation is completed you will be notified. It should not take more than 2-3 minutes for the calculation to complete under normal circumstances. Make sure that you have only one window open at this point. The messages are usually displayed in the first window, and often not in the window you are working in at this point.

Under the Display menu, select Properties. Record the value for the Energy.

1. Based in the observed trends in trends in the heat of formation (=energy), which alkene is the most stable one?

2. Can you explain the product distribution observed for the elimination of water from a-terpinol (see page 22)?

Problems: Check here