DUE%20DATES

1
Organic Chemistry Lab 315 Fall, 2016
2
DUE DATES

• Today
• At beginning of lab Distillation of a Mixture
  Report
• At end of lab - copy of laboratory notebook pages
  for today's experiment
• Next Week
• GC of Distillate Report see my web page for
  instructions.
• Be prepared to calculate a theoretical and
  percent yield for a synthesis reaction. Review
  significant figures.
• Be prepared to give a complete and correct
  literature citation for physical properties of
  compounds used in next weeks experiment.

3
In Lab Today

• Last week for the Distillation experiment
• you distilled a mixture of ethyl and butyl
  acetate by two different methods (simple and
  fractional distillation).
• from the graphs of volume distillate vs.
  temperature, you deduced the mole of the two
  components of the unknown mixture.
• presumably, this was easier for the fractional
  distillation, which should have shown a better
  separation of vol. vs. temp.

4
In Lab Today

• GC Analysis Unknown acetate mixture
• Now you will compare that analysis with the
  results from todays GC analysis.
• Inject a sample of your unknown mixture (A or B).
  Assuming the components elute according to b.pt.,
  you can identify the two components. (You also
  have the retention times from the GC-acetates
  experiment to compare.)
• By calculating the peak areas, you can directly
  determine the mole composition of the unknown.
  
• Compare this result with your conclusions
  derived by graphing the distillation data from
  last week (simple and fractional).

5
(No Transcript)
6
(No Transcript)
7
In Lab Today

• GC Analysis Distillation Efficiency
• Inject the three saved distillate fractions for
  the simple and fractional distillations pure
  EtOAc, pure BuOAC, and a middle fraction.
• Six fractions altogether from Simple and
  Fractional
• Data shared among 4 students
• Compare the GC results with what you hypothesized
  on the basis of the distillation temp. vs. volume
  results.
• For example, is the pure EtOAC fraction as
  seen on the chromatogram really pure, or is there
  a bit of BuOAc?

8
Notes

• Work at the GC in the same group of 4 as for the
  distillation experiment.
• Each student should inject at least once.
• No one may leave the lab until all students have
  finished using the GCs.
• For Report on this GC please pay attention to
  the corrections and remarks that appear on the GC
  of Acetates Report that I have returned to you.

9
Lab Clean-up

• Goodman, Emily E.