Your preparation for the lecture and laboratory section:

Get a lab notebook (you can use the one from Chem 30AL if you still have pages left), a lab coat, goggles and nitrile gloves (the blue or purple version) before you come to the lab e.g. AXE (YH1275, http://www.chem.ucla.edu/~AXE/labsupplies.html). The first lecture will be held on Monday, March 30, 2009 at 4 pm in CS50. Please make sure to show up on time even though the lecture is going to be podcasted this quarter as well. The labs will start on Tuesday, March 31, 2009 at 1:00 pm (for those of you that are enrolled in these labs). Make sure to bring your lab coat (flame retardant preferentially, cotton absolute minimum, no polyester (!) and knee length) and goggles with you as well since you will handle chemicals. Attendance during your first meeting is mandatory. If you do not attend during the first 30 minutes, you will automatically lose your spot in the course. Wait-listed students will be signed up then based on priority (Chem&Biochem majors first, then according to seniority, extension students very unlikely this quarter. Sorry!). Nobody enters the lab before being approved by the instructor!

Required texts are the Course Reader (Organic Chemistry 30BL Reader, Spring 2009), the techniques and spectroscopy reader ("A Short Survival Kit for O=Chem Lab",Spring 2009), the Exam Collection Reader for Chem 30 BL (Spring 2009) and the textbook from J. Mohrig et al. (Techniques in Organic Chemistry, 2^nd edition). The readers are available as bundle at Course Reader Materials in Westwood (1080 Westwood Boulevard, near Rite Aid starting March 23, 2009. They are open from M-F 9-6 pm and the first two Saturdays in the quarter from 10-4 pm (phone number: (310)443-3303). It is in your best interest to have the latest edition of the readers, since this is the source your TA and the instructor use for lectures, quizzes and exams. This is the wrong place and time to save a few dollars. Look at it as an investment of passing the course by having the up-to-date information available to you.

Lecture attendance is mandatory. There will be pop quizes throughout the class in lecture. It is also highly advisable to read the lecture material before hand since it makes it easier for you to understand the material covered in lecture. The lecture time allotted for this class does not permit to discuss every little aspect of this class in great detail. This also means that you will hold responsible to read up on certain aspects on your own in the readers and other sources. However, the instructor will offer additional work-shops on Mondays from 5-6 pm (starting on 3/30/2009) to review spectroscopy (IR, NMR, UV-Vis) and other topics of interest (check web site for schedule and topics).

Please make sure that you registered a working email address with URSA (Note: Hotmail addresses seem to cause problems lately!) and that you actually check it on a regular basis. The instructor frequently uses this method of communication to make general announcements and inform students about changes and other topics.


1. Check-in

Before you come to the lab, make yourself familiar with the names and function of the equipment (see reader) that you will use during this lab course. It will make it easier for you to communicate with your teaching assistant and/or instructor during the check-in procedure and throughout the laboratory course. Please make sure to read the syllabus and any additional material pertaining to the experiment in the lab as well. The final exam will most likely be administered on Friday, June 12, 2009, 11:30am-1:30pm. There will be no make-up exam! Make sure that the time does not conflict with your other classes or your vacation plans for summer break!

Important pieces of glassware i.e. conical vials, Hickman head, and the air condenser should be crack free. Conical vials have to have a ground glass joint, which allows the condenser or Hickman head fit in there tight. If you have a Hickman head with a side port, make sure that you have the appropriate compression cap and flat septum as well. If not, try to obtain it from the lab support (YH 1072) or exchange it. Some pieces of the glassware (i.e. beakers, Erlenmeyer flasks) might have a minor chip at the top, which usually does not interfere with their functionality. If you are in doubt, ask your teaching assistant. Place all extra glassware at a location previously determined by the teaching assistant i.e. hood or separate bench or bin. It is very likely that one of your fellow students is missing it. This speeds up the check-in process significantly, because you and your fellow students do not have to stand in the long line in front of the lab support to get the missing glassware.

The instructor and/or the teaching assistant will discuss different aspects of safety before you start your in-lab work. It is very important that you are aware of the dangers in this laboratory course. This does not mean that you have to 'freak out' handling chemicals. In this course you will encounter more dangerous chemicals than in general chemistry. Some of them are very corrosive i.e. concentrated acids and bases, and some of them are highly flammable i.e. diethyl ether, or other organic solvents. It is part of your preparation to inform yourself about the hazards of a particular compound that you will be using and how to handle it properly in the lab. It is important to develop a consciousness for safety in order to be safe and efficient in the lab. The teaching assistant will show you where the safety related equipment i.e. emergency shower, eye wash, and fire extinguisher is located, and how it is used. Whenever possible try to place your setup underneath the shelf in the middle part of the bench. It is connected to a ventilation system that will remove the majority of the evolved fumes. Proper clothing (closed-toed shoes, low heels, long pants, shirts or sweaters with long sleeves, a lab coat (as described above), goggles and gloves) is still the best protection if an accident does occur and you plan on getting through this lab course unharmed. The"proper dresscode" will be strictly enforced in this course to ensure your own safety. If you are seen without goggles, the teaching assistant will take off points from your in-lab evaluation. If you wear sandals, shorts, short skirts, etc you will be sent home immediately, which means that you will not be allowed to take the quiz and also will lose 10 points for your in-lab evaluation since this shows very poor preparation.

The teaching assistant will discuss the specific format of the lab reports. Please make sure that you read the appropriate chapter in the reader before hand. If something is not clear, feel free to ask the teaching assistant or instructor. Bottom line is that the pre-lab report should show that you have a clear understanding about the experiment that you are about to perform in the lab. Copying from the reader or prelabs from your friends alone is not enough! The post-lab write-up has to demonstrate that you are able to explain your observations and can analyse the obtained data correctly. There are many students who do well in the lab (based on their scores in the reports) and end up getting poor grades in the class, because they just copied reports from friends/roommates/etc. The exam will show if you mastered the material or not. If you fail the exam, it does not matter how well you do in the lab anymore since you have to pass both parts independently from each other.

For the first meeting only you will be allowed to use the reader. Afterwards, you will be deducted points because the use of the reader shows that you are not prepared enough for the lab section. You should include all the information that you need to perform the experiment in the lab in your pre-lab i.e. IR data, physical properties, etc. This rule applies already in meeting 2, which means that you will have to prepare the entire prelab for meeting 1 and meeting 2 for the second meeting.


2. Boiling point determination

Check out a digital thermometer and thermocouple from the lab support (YH 1072). Please make sure that it works properly (T~20-25 ^oC) right when it is handed to you. It will save you the hassle to get in line several times. The device will be used to measure the temperature of the boiling liquid (more accurately the vapor temperature above the boiling liquid). You will need to return both after you are done. Do not lock it up in your desk! The same thing applies to hardware like clamps, etc since this is shared equipment!!

Make sure that the compression cap (=plastic ring in various colors) and the O-ring connect the air-condenser tightly with the conical vial during the reflux. Why?

Even though the determination should be done relatively quickly, the hotplate should not be set to a very high setting right from the start. Why?

Safety note: Do not breathe the vapors of the unknown compound that you get assigned. Some of these compounds are irritant and can cause headaches and/or other problems! Dispose of the liquid in the organic waste container located in the community hood. The same applies to (unknown) samples that you find in your desk during the check-in.


3. Coenzyme synthesis of Benzoin

General comments:

You will also have to start the coenzyme synthesis during meeting 1 (and finish it up during meeting 2. Prepare a prelab for the entire experiment by then since you will not be allowed to use the reader anymore!). It will be the first step of a multistep synthesis project that will follow you throughout the course. During meeting 4, you are going to oxidize benzoin to benzil using bleach. After an aldol condensation (leading to 1,2,3,4-Tetraphenylcyclopentadienone, TPCP), the final product of the sequence will be 1,2,3,4-tetraphenylnaphthalene (TPN). It is imperative that you get a good yield in all of these steps in order to be able to receive a reasonable yield for the final product of this project. You will also use benzoin in the last experiment (Grignard reaction). So please make sure that you get a decent quantity (~1.5 g) of the product.

Experiment:

The addition of NaOH (2N) should be done slowly in order to avoid an excess of base. Why? The color only has to change from yellow to pale yellow. Make sure that you have a homogeneous mixture after you added the benzaldehyde. Make sure that you seal the flask tightly with parafilm. This step will reduce oxidation of the benzaldehyde! You should come back the next day and check if crystals have formed. If not, scratch the inside of the flask to initiate the crystallization. If you do not obtain a solid after scratching and cooling, consult your teaching assistant. If s/he cannot help you, try to consult the instructor as well before you discard the mixture.


4. Critical thinking

a.Which factors determine the boiling point of a compound (Hint: read chapter in SKR)?
b.Why is extended heating not resulting in a more accurate value for the boiling point of a compound?
c.When does a compound "boil" (Hint: How is the normal boiling point defined?)
d.Why is it necessary to add a spin vane, boiling stone (chip) or boiling stick when you boil or reflux a compound/mixture?
e.What does 'heating under reflux' mean? Which purpose does it generally serve?
f. Is an air condenser alone a "useful" piece of equipment for an extended reflux or a reflux for mixture with low boiling points (<50 ^oC)? How can the efficiency of a condenser be improved?
g. Why does benzaldehyde have to be 'fresh' for the experiment?
h. How does the 'scratching the inside of the flask' promote the crystallization process?
i. Predict the missing parameter using the nomograph from the reader: