Welcome
to
Chem 334
Organic Chemistry Laboratory I
334-FPBP and 334-07
M. Séquin
Instructor: Dr. Margareta Séquin
Office: Science 106 C
Office Hours:
Tu 11 – 12; Th 1 – 2 pm; Fr 1 – 2 pm
e-mail: msequin@sfsu.edu
For phone messages: 415 – 405-0315
Prerequisite: passing grade (C- or better) in C 115, C 333 or
C130 (can be taken concurrently). A student who
withdraws from C 333 or C130 must also withdraw from C
334.
Text: “Chem 334, 336, and 338 Organic Chemistry
Laboratory”, SFSU 2005, with Mayo, Pike, Trumper,
"Microscale Organic Laboratory", 4th Edition; Wiley
Custom Edition.
Laboratory Materials:
Laboratory safety glasses (ANSI Z87) or safety goggles
Laboratory notebook, must be bound (not spiral)
Exams and Grading
• Several MiniQuizzes at the end of lab lectures, 2 pts. each
• One Midterm Exam (100 points) on October 27, in your lab,
covering the material of lab and lab lecture during the first half of the
semester. The exam will be given in the respective lab sessions.
• Final Exam (150 pts.) on Dec. 15, in your lab, comprehensive. The
exam will be given in the respective lab sessions.
Please note: An exam not taken earns the grade F.
• Standard lab reports: 20 points/ lab report. Lab report Exp.9 is 30
points.
Late reports incur point deductions.
• Lab Notebooks will be checked regularly.
Total class grade will be calculated as follows:
40% Exam average (Midterm (100 pts.), Final Exam (150 pts.) and Mini
Quizzes (each 2 pts)
40% Lab reports average
20% Lab preparation, notebook, lab skills, maintaining clean work area,
observing safety rules, participation, attendance.
http://userwww.sfsu.edu/~msequin
Chem 334
An introduction to
very common organic lab techniques
• Methods to identify organic compounds
• Methods to separate organic mixtures
Lecture
Lab
SCHEDULE OF LAB EXPERIMENTS
(Refer to your text for Reading Assignments and Procedures)
9/1: CHECK IN. Safety rules. Exp.1, Melting points
9/8: Exp. 2ab; Recrystallization
9/15: Exp. 2c
9/22: Molecular Modeling. Go to SEGA lab, SCI 249
9/29: Exp. 3, Distillation and Gas Chromatography
10/6: Exp. 4, Isolation of Eugenol. IR
10/13: Exp. 10, Isolation of Caffeine
10/20: Exp. 6, Column Chromatography
10/27: MIDTERM EXAM in Lab. Complete Exp.6
11/3: Exp.8, Dehydration of 2-Butanol. GC
11/17: Exp.9, Separation of an Unknown Mixture
12/1: Exp.9 Cont.
12/8: Complete Exp.9. CHECKOUT
12/15: FINAL EXAM in Lab.
Exp.1: Melting points of organic solids
• Which has the highest melting point?
CO2, C6H12O6, NaCl, C5H10, C6H6
• Definition of “melting point”?
Measuring Melting Points
Procedure: Simple Capillary Melting Point
Measuring Melting Points
Procedure: Simple Capillary Melting Point
• Close-up view of the white
crystals in the capillary tube
before heating the apparatus.
• M.P. range is the temperature
at which solid starts to melt to
the temperature at which solid
is completely melted.
Thomas-Hoover
m.p. apparatus
Measuring Melting Points
Procedure: Simple Capillary Melting Point
• Each instrument and thermometer
have slightly different calibrations.
Use the same instrument each time.
Melt-Temp melting
point apparatus
Melting Point Measurements
T = Temperature
Measure :
m.p. range: T start melting - T completely melted
Example:
m.p. 98 - 100 oC
Expt. 1 Melting Points
Chemical Structures relevant to this experiment
o-anisic acid
phenoxyacetic acid
Acetanilide
Fluorene
Mp.: 98-99o
98-100o
113-114o
114-115o
malic acid
Urea
diphenylacetic acid
Cholesterol
131-143o
132-134o
147-149o
147-149o
Question of the Day:
How does the melting point of two compounds
compare to the melting points of the individual
compounds?
E.g. pure Phenoxyacetic acid (m.p.98-100 oC) mixed
with pure anisic acid (98-99oC)?
Or
Pure Fluorene (m.p.114-115 oC) mixed with pure anisic
acid?
?????
Expt 1. Melting Pt of Pure Sample
•You will work in teams of 4 students
•Each student will receive one unknown (1a,
1b, etc)
•Make m.p. measurement of your unknown
(pure compound). Note in your lab notebook
and on the report form.
•Once your team obtains m.p. range for each
unknown, see lab instructor to find out the
names of each unknown.
Table 2. M.p. of Pure Compds (p. 247)
Example for students in Group 1
Unkn #
1a
1b
1c
1d
Cmpd. name
Expt. M.P.
Lit. M.P.
Part A: Melting Pt of Mixture
Procedure
•Student with sample 1a will take a small amount (~10 mg or
small amount on a metal spatula) and place it on a clean
watch glass and then add a similar amount of sample 1b to
make the mixed sample. Stir the solid and break the clumps.
Mix the sample well.
•Place the mixed crystals in a melting point capillary tube to
the height of about 2 mm. Obtain the M.P. range and record
it in Table 3.
•Similarly, mix sample 1b with sample 1c etc. as shown in
Table 3 example on the next slide.
Table 3. Mixed M.P. Data (p. 247)
Expt.
Cmpd.
MP
Expt.
Cmpd.
MP
Predict. M.P.
Expt. M.P.
M.P. mix of 1a
+ 1b
1a
1b
1b
1c
1c
1d
1d
1a
1a
1c
Optional
1b
1d
Optional
Melting Behavior of a Binary Mixture
(see Reading Assignment)
m.p.
.
.
pure B
TF
pure A
Solid A
+ liquid A+B
.
Solid B
+ liquid A+B
E
A 100
0
m.p.
Solid A + Solid B
80
50
50
% Composition
m.p. of E
(TE)
0
100 B
Melting Behavior of a Binary Mixture
(see Reading Assignment)
Some key words and expressions (which you
should look up and be able to define):
Eutectic point, eutectic mixture, mole %
Next class:
• Wrap up Exp. 1: “Melting Points”
• Introduction to Exp. 2: “Recrystallization”