Advanced Laboratory and Safety Rules
Your laboratory work is the core of your chemistry course. You have a challenging opportunity to observe many of the facts of chemistry under controlled laboratory conditions and to deduce from these observations the basic principles which constitute the foundation of the science of chemistry. This is putting into use the ideas of the scientific method.
Some suggestions, rules, and advice:
- Gain self-reliance by working individually, unless the experiment demands teamwork.
- Use your ingenuity and common sense. Laboratory directions, while quite specific, leave ample opportunity for clean-cut, logical, original, and imaginative thinking. This attitude is a prerequisite in any scientific endeavor.
- Don't waste time. Prepare for each experiment by studying it before you come to lab.
- Note beforehand extra equipment required from the stockroom and obtain it all in one trip.
- Prepare the lab report on the current experiment with care. You will use a permanent bound laboratory notebook. Make data entry tables in advance and record directly, in ink, into the final lab report as you obtain it. When calculations are involved, show an orderly calculation for the first set of data, but do not clutter the calculation section with arithmetic details. Likewise, think and answer important questions which have been intended to guide you to an understanding of principles on which the experimental procedure is based as you perform the experiment. Your laboratory instructor will give more specific directions for the notebook and lab reports.
- Scientists learn by discussing with one another. You may likewise profit from discussion with your classmates, but not by copying from them. The best of all science rests first in integrity. You can also get help by frequent reference to your text while in the laboratory.
- Maintain an orderly, clean laboratory desk. Invert glassware over a paper towel to dry. Clean your area with a thorough wash and wipe of the desk top at the end of the lab session.
- Invert washed glassware over a paper towel to dry.
- Discard solids into the appropriate waste containers. Never throw matches, litmus paper, or any insoluble solids into the sink.
- Flush appropriate liquids down the sink with plenty of water. Note: acids, as well as salts of copper, silver, lead, chromium, nickel, and mercury, for example, are toxic, and thus require special collection. If you have a question pertaining to the proper disposal of any hazardous material in the lab, ask your instructor or your CA for directions.
- Read the label twice before taking an anything from a bottle.
- Avoid using excessive amount of reagent.
- Never return unused chemicals to the stock bottle - other students' experiments will suffer.
- Avoid contamination of the stock bottle: do not insert your own pipets or medicine droppers into the reagent bottles. Pour solutions only from the stock bottle.
- Do not lay the stopper of a bottle down. Impurities may be picked up and thus contaminate the solution when the stopper is returned.
- Do not heat heavy glassware such as volumetric flasks, graduated cylinders, or bottles; they break easily. Test tubes may break if they are heated above the liquid level and liquid is then splashed over the hot glass. Evaporating dishes and crucibles may be heated red hot. Avoid heating any apparatus too suddenly; apply the flame intermittently at first.
- For the safety of the class, unauthorized experiments are strictly prohibited.
- Maintain a mature and task-oriented attitude at all times.
- Know the location and operation of the eye wash, fire extinguisher, fire blanket, and safety shower.
- Always wear eye protection! Wear protective goggles at all times in the laboratory, as directed by your instructor. Flush corrosive liquid from the eye with plenty of water using the eye wash fountain for a full 15 minutes.
- It is recommended that contact lenses not be worn in the chemistry laboratory.
- Avoid direct contact with chemicals! If corrosive liquids touch the skin, flood with water. Consult your instructor immediately.
- Never point your test tube at your neighbor or yourself when heating substances. A suddenly formed bubble of vapor may eject the contents violently.
- Do not hold your face directly over an container when noting the odor. Instead, fan a little of the vapor toward your nostrils by sweeping your hand over the top of the container.
- No food or drink allowed in the laboratory. Do not put anything in your mouth until you have washed your hands and left the room. Never taste a chemical or solution in the chemistry lab (poisonous substances are not always so labeled in the laboratory).
- Beware of hot glass - it looks cool and safe to touch long before it actually is safe.
- Use a fume hood for reactions involving poisonous or noxious gases. It is a device that rapidly vents away such vapors.
- To insert glass tubing (including thermometers, thistle tubes, etc.) through a rubber stopper, first lubricate the tube and stopper with water (unless moisture must be avoided) or glycerin. Hold the tubing with a cloth near the end to be inserted, and insert with a twisting motion (if you twist a thistle tube by the "thistle" end, it is easily broken).
- Acid should always be poured into the water, not the other way around (water into the acid). When diluting sulfuric acid, pour the acid slowly into the water, never the reverse order, So much heat is liberated on solution that steam may form with explosive violence.
- Protective clothing must be worn when working in the laboratory. If clothing that exposes bare skin is worn, then a laboratory apron or laboratory coat is required. Sandals and open-toed shoes are not allowed in the laboratory.
- Report even minor injuries to your instructor at once.