CHEM120L Study Guide - Final Guide: Sodium Hydroxide
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CHEMISTRY LAB EXAM REVIEW SHEET
A WHMIS online course must be completed prior to working in the lab.
Attention must be paid to instructors. Clarification must be demanded when needed. Unauthorized
experiments must never be performed. Equipment must never be left unattended.
Sinks and bench tops must be kept clean. All spills and bottle rings must be wiped up immediately.
Aisles and bench tops must be kept free of obstructions and all personal belongings must be stored under
Prior to using a chemical a student must become familiar with it and learn the safe handling and disposal
requirements for that chemical. Attention must be paid to potentially toxic vapour and gases and when
those may occur, work in the fume hood is imperative. When they may be contaminated with chemicals,
hands must be kept away from body until cleaned thoroughly.
Proper equipment must be used when heating flammable chemicals (face shields and protective clothing
when indicated). The working order of the equipment must be verified prior to use.
PROTECTING YOURSELF AGAINST ACCIDENTS/INJURY
Protective clothing must be worn:
o Safety goggles: Splash proof safety goggles are mandatory. They provide maximum protection
from spills and flying objects.
o Footwear: Closed toe shoes are mandatory when chemicals are used.
o Lab Coats: Lab coat use is encouraged.
Food and Drink: No food or drink should be introduced in to the laboratory.
TREATMENT OF INJURY
First aid for skin (cuts, abrasions, burns) contact with acid, alkali or other chemicals is immediate flushing with
copious amounts of tap water. All accidents must be reported to instructor or TA as soon as possible, in order to
insure proper treatment.
Chemicals on the skin: Move to nearest sink, eyewash or emergency shower and flush affected area with
large quantities of water. Inform instructor and if irritation or pain develops, report to Health Services.
Chemicals in the eye: Locate emergency eye wash station nearest to workstation. If chemicals enter the
eye, flowing fresh water must be used immediately for a minimum of 10 minutes. The instructor must be
informed. After flushing, report immediately to Health Services.
Cuts, abrasions, burns: Report to your instructor or TA
EMERGENCY CONTACT INFORMATION:
MAJOR INJURY OR ILLNESS
Fire/Ambulance/Police: Call 911 from any campus phone
MINOR INJURY OR ILLNESS
Health Services: (519) 888-4096 or extension 84096
UW Police (non-emergency): (519) 888-4911 or extension 22222
OTHER HEALTH RELATED CONCERNS
Poisoning/Overdose Information: 1-800-268-9017
Telehealth Ontario (24 hour phone access): 1-866-797-0000
FIRE AND EXPLOSIONS
In order to avoid the ignition of flammable vapours (nearly all organic solvent vapour is flammable) open flames,
electric sparks (switches and motors) and heating elements must be kept away from solvents and, where possible,
vapours must be prevented from escaping containers by keeping caps and lids closed.
The location of the nearest fire exit, fire extinguisher, fire alarm pull station, emergency safety shower
and fire blankets must be known.
If fire alarm sounds, all services (gas, electricity and water) must be turned off and the building must be
evacuated immediately via the nearest exit.
In case of fire or explosion in the lab, the room must be evacuated and the doors must be shut. The
nearest wall alarm must be pulled and the building must be exited via the nearest exit. Smoke and gases
resulting from a fire or explosion should not be inhaled.
If clothing catches fire, stop where you are, drop to the floor and roll to smother the fire. Do not run.
Flammable liquid use should be limited to amount needed.
Apparatus should be assembled so that control valves and switches remain accessible in case of fire.
Carbon dioxide fire extinguishers are located in each corner of the laboratory. They may be used on all fires expect
sodium, potassium, magnesium and aluminum, but are excellent for extinguishing electrical fires. Water should
never be used to extinguish electrical fires.
In order to operate a fire extinguisher, one must employ the PASS technique
Pull the pin or locking device.
Aim low, at the base of the fire.
Squeeze the handle.
Sweep slowly and evenly across the base of the fire.
Fire extinguisher use should always be reported to instructor.
SAFELY HANDLING CHEMICALS
Before using a chemical, one must become familiar with its boiling point, flash point, vapour pressure, toxicity,
explosive limits, incompatibilities and other special precautions. This information is available in the MSDS binders.
Vapours create most of the danger in the laboratory, as they are toxic, flammable, or both. Chemicals of these
types should be handled in ventilated hoods in such a manner that the vapour will be carried away.
Acids must be poured into water, never vice versa.
Any excess chemicals must be disposed of in the appropriate waste container.
Mercury spills must be cleaned up immediately, after consulting a TA or lab instructor.
Neutralize acid or base spills by washing with plenty of water. Spill kits are available in case of large acid or base
SAFELY HANDLING GLASSWARE
Use correct glassware for each procedure.
Chipped or broken glassware should be discarded immediately.
Broken glass should be collected with a brush and dustpan or cardboard. Absorbent cotton may also be
used to pick up fine pieces of broken glass. Cotton should be held with tongs. Paper towels should never
be used to clean up broken glass.
Glassware that is chipped or cracked can break when heated or cooled, often creating a chemical spill or
resulting in injury to the experimenter. Inspect beakers and flasks thoroughly for damage before use.
Vacuum flasks will collapse violently under vacuum if cracked, chipped or otherwise weakened. Tamping
flasks when suction is on full is an unsafe practice. Erlenmeyer and other thin-walled flat bottom flasks are
not safe to use under vacuum. Release any vacuum from all parts of apparatus before disconnecting.
Carry glass tubing and long glassware (burettes, pipettes, thermometers) vertically rather than
Apparatus that can roll such as thermometers, pipettes, etc., should be placed on bench at right angles to
the edge to keep them from rolling onto floor.
All containers should be completely emptied before cleaning. Organic residues can react with strong
Pipettes with ragged-edge or shortened ends should be discarded. Syringes or a propipette should be
used for toxic or corrosive materials.
EXPERIMENTAL TECHNIQUES OF IMPORTANCE
MEASUREMENT OF MASS
ACCURACY AND PRECISION
Accuracy concerns the deviation of a measured or calculated value from the “true” value. Often “true” value would
mean an “accepted” value.
Precision is a measure of the reproducibility of an experiment and can be quantitatively expressed as an average of
standard deviation. A precise measurement is not necessarily an accurate one, as many errors in the measuring
technique could be constant.