Tuesday, Feb 26, 2008 - 4B

Went over diagram, set-up, procedure, safety precautions for Day Two of Distillation of Wood Lab.
Important points to consider when writing procedure and safety:
1. Be sure to put 4-5 boiling chips in the burning test tube BEFORE boiling.
2. Place the bottom of the test tube 5-10 cm above the alcohol lamp. You may need to adjust the height depending on your alcohol lamp. Use the wire screen on the iron ring to help regulate the boiling. Do NOT over boil!!
3. There is no rubber stopper in the collection test tube. Keep the tubing above the level of the collected liquid but below the level of the ice water in the Erlenmeyer flask.
4. Stop boiling when you still have 1.5 cm of liquid left in the boiling test tube. Before shutting off the alcohol lamp, make sure the rubber tubing is above the level of the collected liquid. Turn off lamp.
5. Observe any differences between the two liquids. Are they the same or different? How can you tell?
6. Wait ~5 minutes for the burning test tube to cool down then mix the two liquids back together. Do you get back what you started with? How can you tell?
7. Dump liquids into the designated container. Do NOT dump the liquids into the sink!!
8. Rinse equipment and put away.

If students did not have enough liquid for the Day Two distillation (needed at least 3 cm in test tube) then they ran through another Day One collection.

Shut down and clean up started at 2:30.

For homework, students should complete and type up the write-up for Day One. Students should write up the procedure, material list, diagram, and safety for Day 2.