updated Thursday, July 09, 2015

Rules and Hints for the Laboratory work

1. Keep all bottles closed if not needed. Many chemicals are moisture sensitive and deteriorate fast e.g. concentrated acids or absolute ethanol absorb water which is a problem for other students' work.

2. The experiments have to be completed successfully, which means that they might have to be repeated if they failed or a very low yield was obtained (<25 %, most of the reactions run in 80-90 % yield based on the literature and experience from the past quarters)

3. Keep your work area clean and organized. However, never discard anything before you are 100 % sure that you isolated the final (desired) product. Huh?

4. Follow the procedure in the reader or the advise of your TA/instructor. They usually know the experiment better than you do and have much more experience as well.

5. Come prepared to the lab. If you have important questions in regard of the procedure, ask them before you enter the lab. The TA will have to supervise 12-20 students, which means that s/he does not have time to go over the experiment in great detail with every student. Most of the questions can be answered during office hours or via email/VOH. There are several questions that will definitively have a significant negative impact on your evaluation for the in-lab work:

• Do I have to add a spin vane/spin bar to my flask? Huh?
  
• What does ‘reflux’ mean? Huh?
  
• Is this enough drying agent? Huh?
  
• Is this enough solvent? Huh?
  
• Which setting do I need on my hotplate? Huh?
  
• Is the solution long enough in the ice bath? Huh?
  
• Does this IR spectrum look ok? Huh?
  
• How do I separate the solid from the liquid? Huh
  
• Which one is the organic layer? Huh?
  

The more competent you are in the lab, the higher the lab evaluation will be.

6. Keep in mind that you are enrolled in an advanced level class. This implies that you are expected to do more work on your own (besides that’s the best way to learn the material). It is up to you to find the relevant information for your experiment i.e., safety data, reference spectra, etc., if it is not already in the reader.

7. Formost parts, you work alone on a given project. It is your responsibility to complete the project in the allotted time. The TA is not there to do the work for you.

8. There are two types of tubing: thick-walled tubing (for vacuum and high pressure applications) and thin-walled tubing (used as water tubing). Huh?

9. Use clamps of appropriate size to secure your flasks, vials, filter flasks and other setups, so that they cannot flip over or fall off the hotplate.

10. Use a funnel size that is appropriate for the material that you are handling. Make sure that the filter paper is big enough to cover all the holes, but does not run up the walls. A clean filter flask for each filtration would not hurt either (in case something goes wrong)!

11. When you wash a precipitate, use only a small amount of chilled solvent. Huh?

12. Add a boiling stone, boiling stick or a spin bar into your solution when you boil a solution to prevent bumping. Never fill a container more than half when you plan to boil off the solvent. Huh?

13. If you destroy equipment due to negligence to follow given procedures, you will be hold financially responsible. The current lab fee for the course (currently $60) does not cover this. UCLA will usually charge this fee to the student’s bar account after the 4^th week of the quarter.

14. Make sure that you clean your glassware before you leave for the day, so that you get started faster during the next lab period!