CHEMISTRY 3221
Fall 2011
Lab Coordinator: Dr. Mary Bean, 118 Fleming, 713-743-2761
Your TA’s name:_______________________ Office:______ Office hours:_________________
For the laboratory you will need the following items:
1. The textbook: “Signature Lab Series: Chemistry 3221/3222”. This is a
custom manual published by Cengage Learning.
2. A laboratory notebook which is permanently bound, has serially numbered
pages, and which allows you to make a removable carbon copy which can be
turned in for grading.
3. A laboratory coat - long-sleeved and knee length
4. Sturdy, closed-toed shoes that cover the entire foot. No sandals are
allowed!!
5. Safety goggles (NOT SAFETY GLASSES). The laboratory coat and
goggles must be worn in the laboratory at all times anyone in the laboratory
is doing experimental work.
6. A STRONG, RELIABLE lock for your laboratory drawer. Lock your drawer
whenever you leave your bench, even if you are only walking across the
room! Lock your drawer at the end of every lab period. You are responsible
for any broken, missing, or stolen glassware and equipment.
NOTE: Few lab manuals are perfect! Sometimes adjustments in procedure need to be made for
the best results. The syllabus describes most of these changes, but additional changes may be
necessary. It is the responsibility of the student to make note of any such change when given by
the TA.
SPECIAL NOTE: For safety reasons, if you are more than 15 minutes late to prelab lecture, you
may not perform the experiment.
August 22-27
Orientation, check-in. Wash glassware and watch films on safety and using
standard equipment.
Aug.29-Sept. 3 Meet in the classroom specified by your TA for prelab lecture before going
to the labotatory. Remember to bring your lab coat, goggles, lab manual,
lab notebook (with sections I-V of the Laboratory Format Handout already
completed), and lock. You will not be allowed to participate without the
proper shoes, labcoat and goggles.
Prelaboratory preparation: Read pages 1 – 30 and 45 – 54 of the lab text. You
may disregard the microscale distillation procedures of TECH 0704. Answer in
your laboratory notebook the Safety Quiz on pages 11 – 12 and the Prelab
Questions 1, 2a, 2b, 3 -5, pp. 67 - 68.
EXPERIMENT:
TECH 0704, Distillation, macroscale technique only, simple and fractional:
Substitute a mixture of 25 mL ethanol and 25 mL water for the
toluene/cyclohexane mixture. Record the temperature at 2 mL intervals of
distillate. Use glass beads to pack the fractionating column.
Construct a graph of temperature vs volume for each distillation in your lab
notebook. Compare the efficiencies of the two distillation methods in your lab
notebook.
Postlab questions: 1,3 on p. 65.
Sept. 5
Labor Day Holiday (After today Monday is the last day of the “lab week”.)
Sept. 6-12
Prelaboratory preparation:
Read TECH 0701, Measuring Melting points, pp. 31-44. You may disregard the
procedure described in Part 2. Answer in you laboratory notebook Prelaboratory
questions 1-4, pp. 43-44.
Read TECH 0703, Recrystallization, pp 69-82. Answer in your laboratory
notebook Prelaboratory questions 1-4, pp. 81-82.
EXPERIMENTS:
TECH 0701, Melting points
Part 1: You will use benzoic acid only.
Part 2: omit (You are responsible for the concept.)
Part 3: Perform as written. The possible unknown compounds will be written on
the board.
TECH 0703, Recrystallization: Perform as written. The starting amount of
acetanilide may be changed.
Note Carefully: Retain the products of all experiments until you are given
instructions about what to do with them. In this case, retain the recrystallized
acetanilide for determination of its melting point after it is completely dry (one
week).
Additional notes:
In an experimental procedure, the specification of a quantity as, for example, “60
mg of benzoic acid” does not mean precisely 60 mg, but rather about 60 mg
weighed to the precision of the balance. Always record the actual mass weighed
for use (example 59.51 mg), not the mass specified in the procedure (60 mg). To
insure reproducibility in weighing, always use the same balance when you tare
the container and later when you weigh the container plus the recrystallized
material.
Postlab questions: 4-6, p. 41 and 1- 3, p. 79.
Sept. 13-19
Prelab preparation: Read TECH 0707, Thin Layer Chromatography, pp. 99-108;
TECH 0708, Column Chromatography, pp. 82-90
Prelab questions: 1-3, pp. 111-112 and 1-5, p. 97.
Experiments:
TECH 0707: Part 1: Omit (Microliter pipets will be provided.)
Part 2: omit dichloromethane and methanol
Part 3: Only 3 slides are necessary.
NOTE: Sketch each TLC plate in your notebook. All TLC plates must be turned
in with the lab report. Place them in a sealed envelope and staple it to your lab
report. An evaluation of these plates for appropriate sample application and
concentration, proper marking of developed spots, and correct Rf values will
contribute to the grade.
TECH 0708: Be prepared to perform the dry pack method. Your TA will give you
additional instructions.
Postlab questions: 2-4, p. 95 and 1-4, p. 109.
Sept. 20-26
Prelab preparation: Read TECH 0705, Extraction, pp. 129-135, 139-143
Prelab questions: 1-4, pp. 147-148.
Experiment: You will perform the macroscale procedure only.
Note Carefully: In this and all subsequent experiments, ether is to be removed
by rotary evaporator, not by evaporation into the atmosphere. The TA will
demonstrate the use of this instrument.
Important addition: After isolation, the purity of each compound will be checked
by melting point and TLC. Consider the evidence provided by MP and TLC and
comment on the efficiency of each step of the extraction in your lab report.
Postlab questions: 1-6, p. 145.
Sept. 27-Oct.3 Prelab preparation: Read TECH 0722 (Steam Distillation), pp. 149-155.
Prelab questions: 1-3, p. 169.
Experiment: The semi-microscale procedure will be performed.
Note the following changes: 10 g of ground cloves and a 500 mL round-bottom
flask will be used. Collect at least 100 mL of distillate. Ether, not methylene
chloride, will be used to extract the clove oil (eugenol). With this change the
organic layer is the top layer, and the aqueous layer is the bottom layer. The
ether is removed by rotary evaporator as described earlier.
The experiments described in the section “Characterizing the Product” will be
omitted. A handout describing the conversion of eugenol to a derivative will be
provided.
Oct. 4-10
Finish steam distillation. Post lab question #1, p. 167 should be included in the
Calculations and Results sections of your lab report.
Prelab preparation: Read Properties of Hydrocarbons, pp. 171-172 and TECH
0709, Gas Chromatography, pp. 113-124.
Prelab questions: 1-5, pp. 173 and 1-3, pp.127-128.
Experiments:
Properties of Hydrocarbons: Perform as written. Omit part C.
Gas Chromatography: A mixture of alkanes will be substituted for the mixture
esters on pp. 123-124.
Postlab questions: 1-6, pp. 172-173 and 3-4, p.125.
Oct. 11-17
MIDTERM EXAM
Prelab preparation: Read Nucleophilic Substitution of Alkyl Halides, pp. 175-177.
Prelab questions: 1, 2, 4, p 180.
Experiment: Part A – Perform as written except substitute bromobenzene for
crotyl chloride.
Postlab questions: 1 and 2, p. 180.
Oct. 18-24
Prelab preparation: Handout: SYNT 719, Brominating Alkenes
Prelab questions: 1-4, p. 119.
Experiments: Cis-stilbene and trans-stilbene will be brominated using microscale
techniques.
Postlab questions: 1-4, p. 118.
Oct. 25--31
Prelab preparation: Read Dehydration of Alcohols, pp. 185-189.
Prelab questions: 1 – 5, pp. 188-189.
Experiment: Part B. will be performed as written.
The bromine test on p. 172, Part D. will be used to characterize the product. GC
will be used to determine the ratio of products produced.
Postlab questions (Questons): 1-6, p. 188.
IMPORTANT NOTE: Wash all glassware needed for next week’s experiment
before you leave the lab. Do not wait until next week!
Nov. 1-7
Read the introduction to Triphenycarbinol on pp. 191-192 of the lab manual and
the related lecture text material: Wade, pp. 437-449. The experimental procedure
will be provided in a handout.
Answer the questions in the handout.
Note: The key to success in this reaction is a dry environment! Carefully dry all
glassware as described by the TA. Immediately replace the caps on all reagents
used, especially the ether.
Nov. 8-14
Finish Grignard Reaction
Read ANAL 0729, Identifying an Unknown Alcohol , pp. 197-203.
Prelab questions: 1-6, pp. 207-208.
Experiments: Parts 1-4, pp. 201-203.
Postlab questions: 1-5, p. 205.
Important Note: Wash all glassware and make sure that all of the necessary
equipment is in your drawer for check-out next week. It is your responsibility to
replace anything broken during the semester.
Nov. 15-21
Final Exam (Cumulative) and Check-out.