1. Organic Chemistry Lab 318
Spring, 2012

2. DUE DATES Today Next Week Two Weeks
At beginning of lab – Nitration of Methyl Benzoate Report
Spectroscopy Problem Set, Part II 3.
at end of lab -- copy of laboratory notebook pages for today's work (do not turn in your pre-lab notes or in-class notes).
Next Week
At beginning of lab – Friedel-Crafts Alkylation Report
Spectroscopy Problem Set, Part II 4.
Bring a laptop if you have one. We will go over some of the on-line sites and narrow down your unknown.
Print link from Chem 318 web page (NMR Instructions)
Two Weeks
Identification of Unknown Report

3. Report for next week
The Friedel-Crafts alkylation report + Sep. Scheme are due
Please review the errors you might have made on the Nitration Separation Scheme. There will be more of these this semester (20 points toward total report grade).
Main points:
all starting materials, products and potential by-products should be included (usually mentioned in the exp’t.)
every compound present at the beginning must be separated out from the final product
“separations” include extraction; filtration/decantation; distillation/evaporation/air-drying
it is helpful to print the flow chart provided on the web site
If you have questions about how it was graded, please ask.

4. In Lab Today Product from the Nitration experiment
Write label information on vial containing methyl m-nitrobenzoate (including the % yield you calculated for the report today).
Turn in the product to me.

5. In Lab Today Begin Identification of Unknown experiment
Determine boiling point by simple distillation
Test for water solubility and relative density
Take refractive index
Take IR
Next week, take NMR

6. Experiment Notes Simple Distillation See Pavia p. 720
Distillation gives b.pt.
and purifies compound
I must approve your
set-up before you begin
heating your flask.

7. Experiment Notes Use boiling stone
Receiving flask immersed in ice bath
You may need wrap the apparatus in Al foil.
Do not distill to dryness
Use Al heating block and
hot plate.
Transfer distillate to clean vial.

8. Experiment Notes Refractive Index See Pavia p. 847. Keep text open.
Clean prisms very gently with methanol and tissues.
Do not touch prism with fingers, droppers or other hard objects.
Use 3 – 4 drops of sample
Close hinged prisms together - Gently
Turn on the lamp and move it up toward prisms.

9. Experiment Notes Refractive Index Adjustments: eyepiece to focus;
adjustment knob to move light field dividing line between cross-hairs;
drum to remove colored horizontal band between light and dark field

10. Experiment Notes Refractive Index
Use toggle switch (or button) to view numerical scale.
nD = The last digit is estimated.
Remember to record the temperature of the measurement.
Then correct to the temperature reported in the literature measurement ( per degree). It’s not always 20o. You must report the lit. temp.
Expect to reproduce a literature value to at least the first two decimal places.

11. Experiment Notes Water solubility and relative density
See Pavia, p
This will give you some idea of what functional group is present and/or the number of carbons that are present
It will tell you whether the density is approximately >1 or <1

12. Experiment Notes IR and NMR Take an IR
IR (and all tests) must be done on the distilled compound.
When you are finished distilling, and cleaned up, you can put your name on the blackboard to take your turn at the spectrometer.
Next week you will take an NMR.

13. Experiment Notes
Report is due in two weeks (not counting Spring Break week)
Clean-up today: Escalier and Garland