You received an unsolicited proposal from a self-declared inventor who is seeking investors for the development of his latest idea: a device that uses heat extracted from the ground by heat pump to boil water into steam that is used to heat a home and to power a steam engine that drives the heat pump. This procedure is potentially very lucrative because after an initial extraction of energy from the ground no fossil fuels would be required to keep the device running indefinitely. Would you invest in this idea? State your conclusion clearly and present detailed arguments to support it.

1. During the extraction of trimyristin from nutmeg, two students were given different samples of nutmeg. They noticed that one sample was very fragrant with the characteristic odor of nutmeg, while the other one looked old and was not very fragrant at all. When they asked their instructor about it, she told them it would be OK to proceed with both samples. Still skeptical, they performed the experiment and compared their results. It seemed that there was not much difference: they had approximately identical quantities of the isolated product, with almost identical melting point. Explain. (2 points)

2. During the extraction of trimyristin from nutmeg, the ground nutmeg is refluxed with ether for some time and then filtered to remove the insoluble solids. After subsequent removal of most of the ether by distillation, acetone is added to the concentrated ether extract- after some time, crystals of trimyristin separate out.

a. Explain the need for “reflux” in this procedure.

b. Why is acetone added to the concentrated ether extract? Why not simply allow all the ether to evaporate and leave behind the extracted trimyristin? Explain clearly. (1 point)

c. Where do you expect the impurities to be found? Explain clearly. (1 point)

3. Predict what you would expect to observe when each of the following substances is mixed with NaI/acetone. Would you expect a difference in their relative rates of reaction? Explain. (1 point)

a. 2-chloro-4-ethylheptane

b. 3-chloro-3-ethylheptane

c. 1-bromo-5-ethylheptane

Organic Chemistry lab QUESTIONS Extraction of Caffiene Lab

•Procedure

1) Use hot water to extract the caffeine from the tea leaves.

- tannins and chlorophyll will extract along with caffeine

2) Use dichloromethane to extract caffeine from water using extraction

techniques from last weeks lab.

- dichloromethane is more dense than water and will be the

bottom layer in the separatory funnel.

- perform 3 x 20 mL extractions with dichloromethane

3) Wash the 2 x 20 mL 6M NaOH solution with base to remove acidic

tannins. Tannins will deprotonate and preferentially partition into

the aqueous phase.

4) Dry organic phase with drying agent (CaCl2) to remove residual water.

5) Transfer dichloromethane to flask and evaporate in hood.

6) Recrystallize caffeine from 2mL hexanes and 0.5 mL acetone. Filter, mass product and determine % by weight of caffeine from tea.

7) Analyze for purity via TLC and compare to that that extracted from coke and pure caffeine..