Draw a detailed separation scheme for the isolation of caffeine from the ground tablets.

**Procedure:**

1. Obtain 2 uncoated Vivarin tablets and measure and record their combined mass.
2. Crush the tablets into a powder using a clean mortar and pestle.
3. Place the crushed tablets in a beaker containing about 60 mL of distilled water and about 8 g of sodium carbonate.
4. Add one boiling stone to the beaker and heat the mixture to boiling on a hot plate. Maintain the mixture at boiling for 2 minutes, then stop the heating and allow the contents of the beaker to settle. There will be tablet binder material remaining undissolved.
5. Assemble an iron ring and glass funnel on the ring stand above a 125-mL separatory funnel so that the stem of the glass funnel is positioned in the middle of the separatory funnel.
6. Place a medium-sized wad of glass wool into the bottom of the glass funnel to create a filter.
7. Quickly but carefully filter the Vivarin mixture through the glass wool in the glass funnel directly into the separatory funnel. Rinse the glass wool in the funnel with a small amount of water.
8. Allow the aqueous filtrate in the separatory funnel to cool to room temperature. Do not add volatile dichloromethane to a warm solution in the separatory funnel!
9. Add 8 mL of dichloromethane to the separatory funnel. As you add the dichloromethane, note whether the dichloromethane is the top or bottom layer.
10. Place the stopper in the neck of the separatory funnel. Shake gently, invert the funnel while holding the stopper securely in the neck, and vent the separatory funnel through the stopcock. The caffeine will be extracted from the aqueous phase into the organic phase.
11. Drain the organic layer into a small Erlenmeyer flask.
12. Add two more portions of 8 mL of dichloromethane, repeating the extraction and draining the organic layer into the same small Erlenmeyer flask after each addition.
13. Once the 3 extracts have been collected, add sufficient sodium sulfate as a drying agent. Let the extracts and sodium sulfate sit undisturbed for several minutes after adding sufficient drying agent.
14. Carefully decant the dried dichloromethane solution into a clean and pre-weighed small beaker (50 mL) and then gently evaporate the solvent away in the hood on the low setting of a hot plate.
15. After evaporation, measure the mass of the crude product in the beaker.

**To Recrystallize:**

1. Dissolve the crude material in a minimum amount of hot acetone in a small Erlenmeyer flask.
2. Begin by adding cold acetone (about 12-15 mL) and then gently warming on a hot plate until the crude product dissolves. If the solid has not completely dissolved at the boiling point of acetone, take it off the hot plate and add more acetone, in 2 mL aliquots, then reheat, until a clear, pale-yellow solution is obtained. It may be required to add up to 20 mL or so to achieve this.
3. Remove the acetone solution from the hot plate and allow to cool slightly.
4. Begin adding petroleum ether, one drop at a time, starting with the full amount of a plastic disposable pipet. Keep adding one drop at a time, with swirling after each addition, until the first appearance of a pervasive cloudiness throughout the solution.
5. Recover the recrystallized product by vacuum filtration using a Hirsch funnel. Pull some air through the Hirsch funnel for several minutes after separation to help dry the solid.
6. Transfer the product to a much larger piece of filter paper and allow it to air dry for 20 minutes.
7. After drying, determine the mass and melting point of the final recrystallized product.