CHEM 1B
Dr. R. Rinehart
Laboratory Safety
You are strongly advised to check out the following sites:
as well as the specific
CHEMISTRY LABORATORY CONDUCT
regulations presented below, which have been compiled to promote
safety and efficiency..
General Regulations
Handling of Reagents and Apparatus
Safety and First Aid
Cleanliness
Specific Pointers for Organic Chemistry
GENERAL REGULATIONS
1. Work is permitted in the laboratory only when there is an
instructor in charge. You are urged to perform your experiments during
regular laboratory sessions. Consult your instructor if you want to work in the
laboratory at other times.
2.
Carry out all experiments independently unless directed
otherwise.
3. Record your individual observations directly in your
lab notebook.
4.
Follow directions carefully. This is important for
your own safety and the safety of others.
5. Read the
assigned experiment before coming to lab and write the procedure in your lab
notebook as previously directed. Be prepared to ask questions about any part
of the experiment that is not clear to you. If it becomes apparent that you are
not prepared to perform the experiment, you may be asked to leave.
HANDLING OF REAGENTS AND APPARATUS
1. Chemicals will
be found either on the reagent bench, in the fume hoods, at the center of the
benches, or by the balances. Please leave the chemical containers where you
find them at the beginning of the lab so others can find them easily.
2.
Read labels twice before taking any chemical to be sure it
is the correct one.
3. Never insert an instrument of your own into a chemical
container.
4. Never return chemicals to their original container.
5. When pouring liquids, hold the palm of your hand over the
label. If some of the liquid runs down the outside of the bottle, wash it
with water and dry it.
6.
Always replace the lids on the chemical containers
immediately after use.
7. Set stoppers and lids on the bench in such a way as to
avoid contamination.
8. Be economical in the use of reagents, detergent, deionized
water, and acetone. .
9. Graduated cylinders, burettes and other glassware with
fine graduations should not be heated. Graduated flasks and beakers can be
heated.
10. Be
careful with hot objects. Hot objects should never be placed directly on the
bench. Put them on your ceramic tile.
SAFETY AND FIRST AID
1.
Safety goggles are to be worn at all times in the
lab. It is not only what you are doing but also what your neighbors
are doing that could threaten your eyes. If you get chemicals in your eyes,
flush your eyes out immediately with lots of water for a minimum of 15 minutes.
Notify your instructor.
2. If you have long hair, you should tie it back. Hair
burns easily.
3. Avoid direct contact with all chemicals.
4.
If you spill a strong acid or base, notify your instructor,
who will direct you how to clean it up.
5.
Do not eat or drink anything in the laboratory.
6. In case of fire to clothing, use the safety shower.
7. In case of fire in containers or on the bench, step back,
warn your instructor and others, and allow your instructor to take the
appropriate action. There are fire extinguishers available.
8.
Report
all accidents, including all cuts and burns, promptly to your instructor.
CLEANLINESS
1. You might want
to provide yourself with an apron or laboratory coat. Even skilled workers
cannot always avoid spilling corrosive substances on their clothing.
2. Wash your equipment as soon as you finish using it.
3. Equipment returned to the stockroom should be clean, dry on
the outside, and in good condition.
4. The cleaning procedure usually involves (1) cleaning first
with tap water, detergent and a brush, (2) rinsing with tap water, (3) rinsing
with deionized water, and (4) drying the outside with a paper towel. Do not use
acetone unless directed to do so by your instructor.
5. If you have trouble cleaning something, consult your
instructor.
6.
It is your responsibility to immediately clean up any
chemicals you spill in the lab. If you are not certain how to do this, consult
your instructor.
7.
Dispose of waste in the appropriate place. If you are
unsure where to dispose of something, ask your instructor. General waste
disposal guidelines:
a. WASTE BASKET:
for paper only, no glass or chemicals
b. SINK:
Only water soluble, nontoxic substances. Flush with tap water.
c. SPECIAL DISPOSAL
CONTAINERS: Your instructor
will tell you which substances to place here. For the organic lab, there will be
a minimum of four such containers:
►
halogenated organics: dichloromethane, 2-bromobutane,
bromobenzene, etc.
►
nonhalogenated organic solvents and solutions: alcohols,
aldehydes, aromatics, ketones
►
organic solids: solid products and contaminated items. NOT for
TLC plates, gloves, ....
►
metals waste:
aqueous solutions containing transition metal or
heavy metal ions, such as Cu, Ag,
Mn, Pb, etc
d. GLASS
DISPOSAL CONTAINER: For all
glass waste
8.
Before
leaving the laboratory, clean the sink nearest you and wash and dry your table
top. Be sure that you have not left any apparatus out, that your locker is
locked, and that your key is back on the keyboard.
Specific Advisories
for Organic Chemistry
1.
Use of heating mantles/sand baths
a.
flammability => don’t spill organics onto equipment (clean
thoroughly if you do)
b.
always use controller with heaters
c.
allow to cool before putting away (leave on bench top if you have
to, but good planning counts!)
d.
NEVER HEAT A CLOSED SYSTEM!!!
2.
Common lab setups: DISTILLATION
► familiarize yourself with the properties of reagents being used [e.g.,
bp]
►
always use boiling chips or sticks when heating a liquid to anywhere near its bp
a.
simple distillation, macroscale (ST 19/22)
[see diagram on following pages]
flask, distilling head, thermometer adapter with thermometer,
condenser w/ tubing, receiving head, receiving flask or
graduated cylinder
lubricate joints
support with 3-prong and/or utility clamps at strategic points
use Kem-Klamps
fasten rubber tubing with copper wire
heat with appropriate size mantle & controller
support heater with jack or wood blocks to permit easy removal if
things
get
too hot
b. fractional
distillation, macroscale (ST 19/22) [see
diagram on following pages]
in addition to above equipment, vertical column packed with
Raschig
rings
c. simple micro
distillation [see diagram
on following pages]
flask,
connector w/ rod, distilling head, thermometer adapter with thermometer,
connector, air condenser, receiving container
d.
fractional micro distillation
[see diagram on following pages]
use
vertical tube with loosely packed copper sponge along with equipment in c.
e.
theory of fractional distillation; “plates” [cf Williamson, pp 82-86,
Pavia, pp 565-580]
micro procedures save
time as well as reagents!!
