Organic Chemistry Laboratory
Laboratory Information Packet

Chem 12A and 12B

I.	Regulations for safety in Organic Chemistry Laboratory
II.	Procedures that must be followed in case of an Emergency
III.	Important Telephone Numbers
IV.	Guidelines that must be followed when a student is unable to attend lab or missed a lab due to illness.
V.	Sources of Information about Organic Compounds
VI.	Some common Laboratory Procedures
VII	The Laboratory Notebook

I.

Regulations for Safety in the Organic Chemistry Laboratory

1.

Students may not work in or even enter the laboratory except under the supervision of a member of the instructional staff.

A corollary of this rule is that even the expert chemist should not work alone in a chemistry laboratory unless someone is nearby, in the event that help is needed.

2.

Eye protection must be worn at all times.
Five types of eye protection are available. Listed in order of decreasing degree of protection (which is unfortunately, in increasing order of comfort), these are:

1. Face and neck shields.
2. Laboratory goggles
3. Laboratory glasses with semi side-shields
4. Wrap around laboratory glasses
5. Prescription glasses with sturdy frames and shatterproof lenses.

Only the second and third types are allowed in the Organic Chemistry Laboratories at Ventura College depending on the type of lab. 100% compliance is required 100% of the time

3.

Access to the sinks must not be impeded in anyway

Immediate copious flushing of water is best for cuts and upon contact with corrosive chemicals. Damage to eye tissue is almost instantaneous, particularly by strong acids and bases. If the cornea is involved, partial or total loss of sight is almost certain. (Recall the protective painful response to mildly alkaline soap solution.)

4.

All chemicals, solvents, and reagent solutions should be handled with care and caution.

So many of the materials used in the organic chemistry laboratory are corrosive, poisonous or flammable that all should be treated as if they were. Such an attitude tends to keep one continuously on guard and alert. Clean up spills immediately.

5.

Wash your hands EVERY time you leave the laboratory.

6.

DO NOT eat, drink, or smoke in the laboratory.

7.

A neat work area is the key to successful experiments. Keep your glassware clean. Wash all glassware immediately after use. Remember, "likes dissolve likes." Acetone will clean organic compounds, and soap and water will wash out inorganic compounds, salts, and residues.

8.

DO NOT take reagent containers to your work area.

9.

DO NOT put water insoluble materials in the sinks.

10.

DO NOT put broken thermometers or mercury in trash cans. (Inform the instructor of broken thermometers and spilled mercury for proper clean-up and disposal.)

11.

Immediately report to your teacher:

a) Any accident
b) Any malfunction of equipment
c) Any chemical spills, especially mercury
d) Any broken glassware

An accident report form must be filed for even a minor accident.

12.

Students are expected to conduct themselves in a professional and responsible manner during laboratory period. Please note the following:

1. Each student should confine his/her activities to the workstation, the hood (dispensing/disposal areas), and areas designated for determining melting points and weighing stations.
2. Playing around (physical contact, loud conversations with other students), squirting chemicals or playing with ice, etc. will not be tolerated. The instructor in charge has the authority to expel you from lab if your behavior or conduct is considered inappropriate or irresponsible, you will then receive a zero grade for that assignment.
3. The organic chemistry labs are very crowded. You must therefore move calmly and cautiously when you need to obtain chemicals, equipment and other items necessary for your experiment. Please be aware of others around you. Rushing around in a crowded lab is likely to cause an accident. Be especially careful when you carry reagents from the hoods to your workstation.
4. Do not disturb the other students by having loud conversations and joking across the room. You must carry out your experiment without distracting others around you.
5. It is not advisable to do an experiment if you are on any type of medication that can cause drowsiness (i.e. allergy medicines). If you are on medication, you should talk with your instructor about rescheduling the lab that day. You must stay alert while doing an experiment.

13.

Wear attire compatible with the special hazards of the laboratory.

Wear inexpensive cotton or wool clothing. A laboratory apron or coat is recommended. Many synthetic fabrics are very flammable, particularly fuzzy sweaters. (They also dissolve in many of the solvents used.)

Long hair is a serious fire hazard. Braid or tie it in a ponytail.

Sandals and open-toe shoes offer inadequate protection to the feet and you will not be permitted in lab with such attire.

Showers and hand sprays are located near the entrance to the laboratories. Use the showers or hand sprays in the event of serious contact of the skin or clothing with chemicals. Make sure that you know where the safety showers and hand sprayers are in the lab.

14.

Guard against and be alert for fires.

The relative fire hazard of six commonly used solvents are given in the table below. In general, the lower the boiling point (bp), flash point and ignition temperature, and the greater the flammable limits, the greater the fire hazard.

Liquid	bp (°C)	Flash Point (°C)	Ignition Temperature (°C)	Flammable Limits^1
Carbon disulfide Ethyl ether Hexane Acetone Benzene Toluene	46 35 68 56 80 111	-30 -45 -30 -20 -17 4	100 180 260 538 562 536	1.3 - 4.4 1.9 - 48 13.7 - 7.5 2.6 - 12.8 1.4 - 8.0 1.2 - 7.1

¹Volume % in air. Data from Handbook of Laboratory Safety. The Chemical Rubber Company. Cleveland, Ohio, 1957, pp. 442-550

The flash point is the temperature of a liquid at which its vapors form an ignitable mixture with air. Sustained burning does not usually occur until the liquid reaches a slightly higher temperature, the fire point. The ignition temperature is the minimum temperature of the ignition source, which will cause the initiation of self-sustained combustion of the vapors of a liquid at or above its fire point. The flammable limits are the lower and upper volume percent of the vapor air within which a flame will propagate.

The temperature of a natural gas burner flame can be as high as 1200°C. Electrical sparks, glowing matches, and cigarettes are several hundred degrees above the ignition temperatures listed the table.

Consequently:

1.	Never heat an organic liquid, which boils below 400°C in an open vessel with a burner flame.
2.	Extinguish burners and turn off electrical heaters immediately after use.
3.	Keep flammable liquids away from burners and electrical heaters.
4.	Do not plug heating mantles directly into the power outlet. Heating mantles must be connected to the variac, which in turn is plugged into the main outlet.
5.	Do not smoke in the laboratory.
6.	Do not discard glowing matches into the sink or trashcan.
7.	In the event of fire in a vessel: a) Keep calm. Keep actions deliberate and careful. Alert your neighbors. Send someone for the instructor or a prep room assistant. b) Remove other flammable materials from the vicinity. c) Extinguish burners and turn off electrical heaters, or remove them. d) Extinguish the fire, if you are sure you can do so safely. Otherwise, leave this to your instructor. A fire in a flask can be clamped to a support stand or something standing on the bench top is easily and safely extinguished by sliding a watch glass over the moth of the flask. Special care is necessary not to tip over the flask, which is merely supported on a wire gauze or ring above the bench top. A fire in a small beaker can be extinguished in the same way, but if the beaker is large, the fire is better left to your instructor to treat as the situation demands. Except for burning liquids that are miscible with water, water should not be used to extinguish fires in the laboratory vessels. In the event of ignition of spilled liquids (methanol, ethanol, acetone, and a few others), water is not an effective suppressant unless applied in a fine spray.

15.

Attendance in Laboratory is mandatory.

16.

If you have not prepared (i.e. read and thought about) the lab, you may be "ASKED" to leave the laboratory and not permitted to begin or continue the experiment until you are prepared. You will not be permitted to take a make-up for the experiment. Basically, you should know why every operation you will do that day is being done and how to do it. If you do not know, you should see your instructor BEFORE coming into the laboratory.

17.

There are no make-up labs.

18.

Only authorized personnel wearing safety goggles are permitted to enter the laboratory during the lab times. Visitors (spouses, friends, etc.) are not allowed inside the laboratory during laboratory times. In case of an emergency, however, the instructor in charge should be contacted. He or she will convey the message to the student concerned. This rule will be strictly enforced.

19.

In case of emergency, a student in lab may be contacted by dialing 654-6339 (the Arts and Sciences office). A secretary will get in touch with the instructor or student. It would help if the person calling can identify your location, i.e. SCI 216.

II.

Procedures for Emergencies

1.

Notify the instructor as soon as possible if an accident occurs, follow guidelines and fill out an accident report form.

2.

Know the location of the safety equipment in your lab, specifically the eyewash, shower, fire blanket, and fire extinguishers. Know the location of the campus infirmary and the telephone number (7-3174).

3.

Accident reports must be filed for all injuries. Many injuries will require medical attention and time is usually of the essence.

4.

For burning clothing or large chemical spills on the body, walk to the shower immediately. For chemical spills, remove contaminated clothing under the shower. Note the location of the shower in the lab - safety showers are located near the entrance of each laboratory.

5.

For chemicals in the eye, flush immediately with large amounts of water, holding the eye open. Note the location of the eye wash station. Wash eyes for 15 - 30 minutes or until emergency personnel arrive to treat the eye injury. Emergency personnel should be called immediately.

6.

For chemicals to the skin over a small area, or small burns, wash immediately with large amounts of cold running water.

7.

For large chemical spills in the bench or floor, immediately alert your neighbors and the instructor and clean up as directed.

8.

In case of fire, call the instructor. Small fires maybe smothered by covering them with an inverted beaker or watch glass.

9.

A First-Aid station is located in each PSC 215, which contains the following:

Adhesive Bandages Bulk Gauze First-Aid booklet Burn Cream Scissors

Sterile pads Eye pads Antiseptic wipes Antiseptic cream Tweezers

Sterile sponges Adhesive tape Cold packs Absorbent cotton

10.

A telephone is located in PSC 215 (777-2117)

11.

If an injury occurs during normal working hours, your TA should call the Student Health Center at 7-3174. After 5 PM, the TA should call 7-4215 (campus polics). An officer will arrive at the scene of the accident within 10 minutes and escort the student to the Emergency Room at the Baptist Medical Center. If serious injury occurs, call 7-9111 on campus.

12.

Try to watch out for your fellow students. If something happens to your neighbor and he or she is confused or in shock, call for the attention of a TA or send someone to get the TA's attention and try to bring help to someone that can't ask for it themselves.

III.

Important Telephone Numbers that you must have in your lab notebook.

1.

Chemistry Office: 777-5263

2.

Student Health Center: 777-4174 (8:30 AM - 5 PM)_

3.

If an accident occurs after 5 PM, call campus police at 642-7000. An officer from the campus police department will arrive within 10minutes and escort the injured individual to the Emergency Room at the hospital.

4.

If serious injury occurs after 5 PM, dial 642-7000 for fire, police, paramedics, and ambulance. Calling 911 will delay emergency personnel since they won't know where to go on campus unless the campus police tell them where to go.

5.

Your instructor's phone number, email address, and office location will be given to you during orientation. You may also contact your instructor by leaving a message in his or her mailbox in the Arts and Sciences Department Office.

6.

Laboratory Manager's office: 657-3277.

IV.

Guidelines that must be followed if a student is unable to attend a lab period or missed a lab assignment due to an accident or illness.

1.

If you know ahead of time that you will not be able to attend a particular lab period, you must talk to your instructor and re-schedule for later that week. Your instructor may arrange for you to do the experiment in a different lab or time.

2.

If you missed a laboratory session due to ill health or an accident you should contact your instructor as soon as possible after your return to campus. This may be done by:

a) Contacting your instructor by phone. If your instructor is unavailable, please leave a detailed message with your phone number so that the instructor may contact you.
b) Each instructor will have scheduled office hours posted on their office door. Drop by and see your instructor during those times.
c) If you are unable to meet your instructor during office hours and you have not had a response to your telephone messages, you may leave a written message in your instructor’s mailbox in the Arts and Sciences Department Office (Sci 315A). Please make sure you leave a contact number.

V.

Sources of Information about organic Compounds

In your laboratory write-up, you are asked to prepare a list of reagents and products to be used or synthesized as a part of the prelab for each experiment. Such a list should include physical data i.e. molecular weight, melting or boiling point, density (of liquids), etc. Special hazards or handling problems should also be noted.

Listed below are two of the more common sources for such data and one larger, more comprehensive work. All of the sources are available in the library.

CRC Handbook of Chemistry and Physics: (Chemical Rubber Company) A valuable source of constants (MW, mp, b.p., etc.) for several thousand organic and inorganic compounds. The volume is updated annually; the latest edition has an expanded organic section. There is also much useful information about inorganic compounds as well as a host of physical constants and a very complete integral table.

The Merck Index: A chemical dictionary of 10,000 or so organic compounds. Because Merck & Company owns a pharmaceutical house; this book has somewhat of a biological/medical slant. It is, however, fairly complete as an organic chemistry reference. For each compound, it lists the IUPAC nomenclature and all the "trivial" names, appropriate constants, and potential hazards and toxicities. There are also a section of named organic reactions. It is well cross-referenced and convenient for use.

Several on-line sources available from the web site: http://chemserv.ventura.cc.ca.us/doliver3/chem12a/o-chemicalinfo.htm

Citing References: Whenever you list physical constants in your lab notebook, you should acknowledge the source of your data. Not doing so is plagiarism.

March, Advanced Organic Chemistry, 2nd Ed., McGraw-Hill, NY. 1977; pp. 1155-1156.

VI.

Some common Laboratory Procedures

A.

Comments on Cleaning glassware, disposal of waste chemicals, and maintenance of equipment

Cleaning Glassware

1.

Glass assemblies are best cleaned immediately after each use.

2.

Wipe off the grease on all ground glass joints with a paper towel soaked in acetone. Washing with detergent and water should follow this.

3.

A knowledge of the nature of the chemicals in your reaction flask helps a great deal in the proper clean up of the glass apparatus. Water, soap and brush will do an excellent job on water-soluble or water miscible compounds or substances. Organic materials are easily removed by washing twice with a few milliliters of acetone. Tarry residues can be easily removed by soaking in acetone for 15 minutes, followed by a soap and water rinse.

4.

The improper drying of your apparatus could affect the results of an experiment. The Grignard reaction is highly moisture sensitive and will fail to start if only trace amounts of water are present. For the routine drying of glassware, squirt a few milliliters of acetone in/on glassware after the regular wash, and then set aside on a drying rack. Towel dry glassware that has easily accessible surfaces, (beakers & watch glasses).

5.

There is no need to dry glassware that will be used with aqueous solutions.

Waste Disposal

1.

Organic waste should be collected in specially labeled containers.

2.

Generally, aqueous solutions can be poured down the drain with ample amounts of water; however, ask before you pour.

3.

Broken glassware, vials and pipettes must be disposed of in waste containers marked "Glass Only"

4.

Waste mercury (from broken thermometers) must be disposed of in a special container. Ask your instructor for help with mercury waste.

Maintenance of Equipment

1.

The hot plate-stirrer should be wiped clean immediately after each use when it has cooled down. Do not immerse the apparatus in water.

2.

The balance should be cleaned after each use. Any paper used in the process should be discarded.

3.

Any chemical spills should be cleaned immediately.

4.

At the end of a lab period, the lab bench should be cleaned with paper towels and washed with soap and water, if necessary. All waste should be discarded in the proper receptacles.

5.

Heating mantles must be cleaned after cooling to room temperature. The cord is to be wrapped around it and it is to be placed in the center of the bench.

B.

Weighing and Measuring

Solids are conveniently weighed on weighing paper on the pan balance. If the solid is an irritant or is sensitive to light or air, weigh in a stoppered Erlenmeyer flask. Always remember to clean the balance area after each use and observe the following:

1. Do not weigh anything that is hot or warm.
2. Remember to tare the container prior to weighing.
3. Avoid drafts, bumps or excessive movement close to the balances.

The volumes of liquids can be measured by means of a graduated cylinder, or more accurately with a burette, volumetric flask or calibrated syringe. If the density of the liquid is known, the weight can be calculated by using the simple relationship:

Mass (g) = density (g/mL) x volume (mL)

In reading the volume, always take the reading from the bottom of the meniscus at eye level. When dealing with small quantities of liquids, it is much more accurate to weigh them than to record a volume.

C.

Handling Chemicals

Many chemicals are potentially quire dangerous. Observe the following guidelines when handling chemicals.

1.

Use the hood for the transfer of volatile liquids and other dangerous chemicals.

2.

Read the label carefully.

3.

Never pipette by mouth.

4.

Use rubber gloves when handling reactive reagents.

5.

Hold the bottle away from your face.

6.

Use a short stem funnel to avoid spillage.

7.

Clean up spills, as instructed, immediately.

8.

Never dip a contaminated pipette into a liquid container, or an unclean spatula into a solid container.

9.

Do not pour any unused liquid or solid back into reagent bottles. To avoid waste, pour out only what you need for the experiment. You do not want to contaminate the reagents, which are to be used by other students.

10.

Most of the commonly used solvents are volatile, flammable and readily absorbed through the skin. Therefore:

a) Use disposable gloves (Derma Shield protective hand covering foam also offers protection.
b) Keep only a minimum quantity of flammable liquids on your bench.
c) Keep solvents away from heat.
d) Never heat solvents over a burner or hot plate.
e) Do not smell organic liquids.

Toxic solvents include aromatic hydrocarbons, organic acids, esters, halogenated hydrocarbons, carbon disulfide, methanol, and certain amines.

11.

Rinse chemicals from flasks before overnight storage. If you must store chemicals in your locker, remember that besides contamination, disastrous consequences can occur. (Tollen's reagents have been known to explode upon overnight storage.)

12.

In general, if you have any doubt about the nature/toxicity/hazard of any chemical you contemplate using, it is your responsibility to look up its properties. If you have any questions about any chemical, see your instructor.

D.	Storage of Chemicals
	Chemical compounds will deteriorate, decompose, or form by-products if they are not purified and stored properly. In addition, improper storage may be a safety hazard. Observe the following guidelines for the proper storage of your compounds.
1.	Store your compound immediately after completing the reaction work-up, preferably upon isolation if a pure product. Impure compounds or products that have not been worked-up properly tend to deteriorate quickly.
2.	Leave products or reaction mixtures that need further work-up (and have no special storage recommendations) in your assigned area. Clearly label (student's name, name of compound, experiment name, and date) and stopper the container. Volatile liquids should be stored in special areas i.e. your reaction product in ether should not be stored in your drawer. Consult your TA if you have problems.
3.	If your compound is a liquid, store in a clean, tarred, and clearly labeled vial. Place a piece of aluminum foil underneath the cap (sometimes liquids can react with the inside of the cap) and store appropriately.
4.	Dry solids may be stored in clean dry, labeled vials and stoppered. Solids, which are wet with solvent or water, should be placed in a sample vial covered with foil, which should be "perforated" in order that the solid will air dry. The vial should be placed in a small beaker. Under no circumstances should solids be placed on pieces of filter paper and left in the drawer.
E.	Heating and Cooling
Methods of Heating
A.	Steam Bath: This is probably the safest method of heating. It is used for recrystallization or sublimation experiments and for warming organic liquids/solutions in Erlenmeyer flasks or beakers. The utmost care should be taken to avoid steam burns.
B.	Hot Plate/Stirrer
	This is the most convenient method of heating since you have the added advantage of being able to stir your solution magnetically as you heat. It is generally used for heating aqueous solutions/mixtures or for high boiling organic liquids in Erlenmeyer flasks or beakers.
C.	Heating Mantle (Thermowell)
	This device is designed for heating organic solutions/liquids in round bottom flasks, such as in the distillation of an organic liquid, or during a reaction (e.g. the Grignard Reaction, the Aldol Condensation, etc.) Heating mantles come in different sizes to fit the different sized round bottom flasks. The exact size and fit is important in maintaining efficient heat conduction (Heating mantles can be used with smaller round bottom flasks if sand is used to promote heat conduction. This will be done the majority of the time.) The heating mantle must be used in conjunction with a variac (Powermite) temperature control. The following procedure should be followed when using a heating mantle. 1) Use the right size-heating mantle to fit the round bottom flask. (Use sand for proper heat conduction when using smaller round bottom flasks.) 2) Before you set up the apparatus, plug the heating mantle into a variac and turn it to a setting of 30 - 40. Make sure that the variac is plugged into the main outlet. Cautiously touch the inside of the heating mantle to make sure that the unit and variac are working. If the heating mantle does not warm up within 5 to 8 minutes, check the plugs to make sure the connections are tight. If this does not help, a fuse may have blown. Consult your instructor for assistance. 3) Never turn a variac higher than 80 without consulting your TA. This is to insure that overheating of some volatile solvents does not occur. 4) Under no circumstances should you plug the heating mantle directly into the power outlet. 5) Under no circumstances should the heating mantle be left on when not in use.
Methods of Cooling
	Many reactions are too violent at elevated temperatures and thus are conducted at room temperature or occasionally at substantially lower temperatures. For example, the Diels-Alder reaction is conducted at 0ºC to prevent the decomposition of diazomethane. The following methods are used for cooling: A) Ice baths: A mixture of crushed ice and water in a beaker should be kept handy during violent reactions (e.g. Grignard) to slow the rate of reaction/reflux or placed beneath a receiving flask for the collection of low boiling products. The temperature of such an ice bath is generally between 3º and 5º C. B) Salt added to Ice Bath: Regular salt (sodium chloride) can be added to ice baths to lower the temperature to about -10º C. Such ice baths are used to induce crystallization of certain compounds from solutions.
F.	Drying Procedures
	Liquids and Solvents Liquids and solvents containing reaction products that have come into contact with water are said to be wet. During the work-up/purification process, these wet products need to be dried. This is accomplished by a process known as chemical drying. A solid drying agent is added to the liquid which reacts with the water present and forms a hydrated compound. The drying agent should not react chemically with the liquid or form emulsions. The liquid with the product then needs only to be separated from the solid drying reagent by carefully decanting off the liquid or filtering out the solid. The following desiccants are recommended of one is not specifically mentioned in the work-up procedure of the of the experiment: 1. CaSO4 forms a dihydrate, CaSO4 * 2(H2O), is efficient and rapid, but has a low capacity. 2. MgSO4 forms multiple hydrates, MgSO4 * n(H2O), is na excellent drying agent, but requres careful filtration to remove once it is hydrated. 3. Na2SO4 forms a decahydrate, Na2SO4 * 10(H2O), has a high capacity, but requires more time to accomplish the drying.
	Solids A solid can generally be dried by spreading it between two filter papers, then storing it in a sample vial covered with foil, which is perforated in order to allow air circulation. The vial can be placed in a beaker and left overnight in a drawer. It can also be placed in a small beaker and left in a drying oven with care taken that the temperature of the oven is well below the melting point of the compound. A third method is to use a vacuum desiccator.
G.	Recording a Melting Point (Range) of an Organic Solid
1.	Melting Point: The melting point (mp) of a pure compound is defined as the temperature at which the solid and liquid phases of the compound are in equilibrium at a pressure of one atmosphere (760 Torr or mm or Mercury). The mp is probably the single most important criterion for determining the purity of a solid compound. The melting point of a pure compound is generally quite sharp, usually melting within a degree or two, whereas an impure compound will melt over a wider range. As a rule of thumb, if the melting range of a particular compound exceeds 3°C, then the compound is impure and requires purification. Mixed Melting Point: Since very few compounds have the same melting point, this physical property is also used for the determination of the identity of organic compounds. the identity of a particular compound can be verified further by carrying out a mixing melting point determination. When a pure sample of a suspected compound is mixed with your unknown compound, and the mp remains unaltered, the two compounds forming the mixture are declared identical since the mixture of the two different compounds would have caused a depression in the observed mp lower than either individual compounds.
2.	Preparation of a Sample for Melting Point Determination: A small amount (5 to 10 mg) of the solid is placed on a clean piece of filter paper and crushed to a fine powder by the application of gentle pressure with a clean metal spatula and then scraped into a small mound. The finely powdered solid is then collected in the opening of the capillary tube (a capillary tube closed at one end). This is usually done by filling one of the melting point tubes by pushing the open end into the mound of powder using a spatula as a backstop. When a small plug of powder has collected in the opening of the capillary tube, work the material down the sealed end by scratching the capillary tube with a file while holding it lightly at the top. Repeat this process until a column of powder about 3-5 mm in height has been collected in the capillary tube. Tap the powder compactly in the capillary tube, as for example, by dropping it on the desk several times through a 2 foot length of glass tubing.

3.	Melting the Sample: Insert the melting point tube in one of the three capillary wells of the Mel-Temp apparatus (see Figure 1). Rotate the voltage control knob to "0" and turn on the apparatus. Make certain that the sample in the melting-point tube is visible in the viewing lens. Adjust the voltage control knob to a setting that will give a reasonably rapid rise (about 5°/minute) to within about 15 - 20°C below the anticipated melting point. (To determine the voltage setting to be employed, use family of curves in Figure 2 in which temperature is plotted against time.) when this temperature has been reached, quickly lower the voltage setting to a value that will give a heating rate of about 2°C change per minute during the actual determination of the melting point. You should be able to get satisfactory results by using an initial voltage of 60 volts, then at a temperature of 15 - 20°C below the anticipated melting point quickly lowering the voltage to 35 volts if your sample 100 and 120°C, to 40 volts if it should melt between 120 and 140°C and 45 volts if it should melt between 140 and 160°C.
4.	Recording the Melting Range: Record the temperature at which you see the first sign of liquid and record the temperature at which the solid-liquid transition is complete. This is the melting range of the sample.
5.	Do Not use the capillary tube and the sample for a second melting point determination. If you need to recheck the melting point recorded on your sample, you need to repeat the procedure previously described. it is generally necessary to wait for a time between mp determinations in order to allow the apparatus to cool. Inaccurate results may be obtained if the waiting period is neglected. It is also a good idea to use the same apparatus for all the melting point determinations to be run during a single experiment. Be sure to turn the voltage control to "0" and turn off the apparatus as soon as you have finished. Cause of Incorrect Melting Points: A) It is important that the sample be dry and thoroughly crushed before it is introduced into the capillary tube. B) The rate of heating is critical - too rapid a rate of heating nay cause a deviation in the melting range from the expected value. C) Impurities generally lower the melting range.
VII.	The Laboratory Notebook (Duplicating)
	The Laboratory notebook is an essential part of doing any research activity. Even though you will not be doing research in this laboratory, your laboratory notebook will be modeled in the style of a research notebook. The laboratory notebook is a record of all data (weights, melting points, etc.) plus all observations (color changes, loss or gain of homogeneity, etc.) made during the course of the experiment. a satisfactory notebook will allow a researcher working to repeat a successful experiment or give guidance concerning modifications needed to turn failure into success. The notebook should be just as understandable and useful to you a year after the experiment as the day after. It should also be written so as to be equally useful to some other experimentalists. Each notebook page should, with the help of spacing, paragraphs, equations, headings, etc., be structured so as to allow quick scanning and location of information. The following rules illustrate the style that you should use. You should always use a page number, a date, and an experiment title. A reaction equation helps locate experiments in a large book and also provides space for recording molecular weights for typical preparative experiments.
	Rules
1.	The laboratory notebook must be bound (duplicating notebook). No spiral, loose-leaf, etc. styles will be allowed.
2.	All entries are to be made in PEN. DO NOT USE PENCIL!
3.	Cross mistakes with one line. No scribbling out mistakes. Do not use white-out.
4.	No pages except the carbon copies are to be removed from the notebook.
5.	Each page must be numbered with the dates of the activities recorded.
6.	No more than one experiment should appear on any single page.
7.	Structures for compounds and equations for reactions must be shown.
8.	All data and information must be entered directly into the notebook at the time of observation. (i.e. It should not be transferred later from notebook paper into the lab notebook.)
9.	An index should be kept on the first page of the notebook.
10.	Carbon copy pages containing the prelab write-up should be checked by your instructor before starting the lab. The post lab with experimental observations/results/conclusions must be handed in before leaving lab.
11.	Your results should be concluded at the end of your notebook entry. The conclusion should include identity of product, yield, % yield, mp, etc. when appropriate. See the web for more details http://chemserv.ventura.cc.ca.us/doliver3/chem12a/lab/reports.htm
Before you begin a new experiment, you should record certain relevant information in your notebook. This should include:
1.	Your name and the date on each page.
2.	The title of the experiment.
3.	An equation for the reaction being performed (Preparative Experiments). Overall reaction and then the mechanistic steps how the reaction works should be included.
4.	A table of reactants, products, reagents and stable intermediates (Preparative Experiments) or compounds that will be examined (methodology experiments). The table should include the structural formula, molecular weight, bp, mp, and some information regarding potential hazards (e.g. flammable, eye irritant, highly toxic, corrosive, stench) of each substance that will be used or formed in the experiment. Other information like color, density (liquids), crystal structures (solids) might help identify the reactants, products and solvents.
5.	An outline of the procedure to be followed including weights and volumes of materials used should be written in the notebook for use during lab (You will exclusively work from and record in your laboratory notebook during laboratory.) Calculations of theoretical yields should be done so the maximum possible amount of product is known.
	Observations such as color changes, gas evolution, precipitation; phase separations and the like should be noted during the execution of the experiment. Upon completion of the experiment, you should record the weight of the product (Preparative Experiment) and compare its properties (bp, mp) to those recorded in your table. In certain experiments, the principle infrared or p-NMR peaks should be recorded and assigned. You should also record conclusions reached from the experiment.