Unit 2　In the lab

扩展资料

Lab safety

　　The following is a list of basic, safe laboratory practices which are expected of all students.(Many of these are common sense rules)
1.) Eye protection (minimum: chemical splash goggles) must be worn at all times in the laboratory.
2.) Students should wear durable clothing that covers the arms, legs, torso and feet. (note: sandals, shorts, tank-tops etc. have no place in the lab. Students inappropriately dressed for lab, could be denied access)
3.) To protect clothing from chemical damage, wear a lab apron or lab coat. Long hair should be tied back to keep it from coming into contact with lab chemicals or flames.
4.) An open flame may be ignited only when no flammable solvents are in the vicinity. The person lighting the flame must check with students in the vicinity to see if they are working with flammable solvents.
5.) Exercise great caution in handling volatile, flammable solvents such as ethisterone and methanol. Never evaporate these solvents on a hot plate in an open system. An efficient condenser system must be used.
6.) In case of injury (cut, burn, fire etc.) notify the instructor immediately
7.) In case of a fire or imminently dangerous situation, notify everyone who may be affected immediately, be sure the lab instructor is also notified.
8.) If chemicals splash into someone's eyes, act quickly and get them into the eye wash station, do not wait for the instructor.
9.) In case of a serious cut, stop blood flow using direct pressure using a clean towel, notify the lab instructor immediately.
10.) Know the location and operation of :
Fire Extinguishers
Safety showers and Eye Wash Stations
Fire Alarm Boxes
Exit Doors
Telephones
11.) Eating, drinking and smoking are prohibited in the laboratory at all times
12.) Never work in the laboratory without proper supervision by an instructor.
13.) Never carry out unauthorized experiments. Come to the laboratory prepared. If you are unsure about what to do, please ask the instructor.
14.) Never pipette using mouth suction. Avoid inhaling and never taste any chemical in the lab.
15.) Never force glass tubing through a rubber stopper. If glass tubing must be inserted into a rubber stopper, be sure to lubricate both the stopper and the tubing (glycerol or soapy water). Protect your hands, wrap the glass tubing in a towel while inserting.
16.) Always remember, HOT glassware looks exactly the same as COLD glassware, be careful what you touch. 100°C = 212°F (boiling point of water).

Preparing for lab

　　The student laboratory plays an important role in allowing the student a "hands on" opportunity to verify chemical principles and learn important techniques for safe chemical manipulation. In order to get the most out of the laboratory this list of simple suggestions has been prepared.
　　Read the laboratory experiment and any suggested additional reading (s), before coming to lab. Do the assigned pre-lab exercises (if any).These generally cover any calculations or important observations which need to be made. Make a list of questions regarding the experiment. A simple question can save hours of time in the lab.
　　All data should be recorded in a sturdy laboratory notebook. Do not use sheets of paper or 3 ring binders, as these pages can become quickly lost.
Make a brief outline of the experiment in your notebook as a way of speeding up getting started, including calculations for needed reagents.
　　It is sometimes necessary to modify lab procedures on the day of the lab to obtain better results. If you are prepared these changes should be easy to make.
　　Prepare data tables ahead of time. Well prepared data tables not only speed up the recording of data, but also aid greatly during report writing.
Clean your glassware at the end of the period so it will be ready the next lab. Many students waste time washing and drying glassware only to find out the large beaker they just cleaned and dried will be used to boil water. THUNK THINK!!!!!
　　Many students are so busy trying to get done they forget to write down their observations. Color changes, endothermic or exothermic changes, physical state changes, boiling points, melting points, freezing points, etc.
Look at the data, does it look reasonable for the type of experiment? When in doubt repeat a portion of the experiment, there is no better teacher than finding your own mistake. If you are still unsure, the lab instructor should be able to help, ask him or her.
　　Lab instructors will sometimes discuss the important aspects of the lab with students individually or in small groups in an effort to help them get more out of the experiment. Keep your ears open and you may hear something that will help you out.
　　Lastly, it is important to follow the safety do's and don'ts of the laboratory, not only for your own safety but also your fellow classmates. Report the dangerous lab practices of others, you will be doing them (and yourself) a big favor.