experiment practical

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Chemistry 234Organic Chemistry Laboratory

Schedule of

Experiments

General Information

Check-in

Laboratory Safety

Lab 1 -- Melting

Point

Lab 2 --

Recrystallization

Lab 3 -- Fractional

Distillation

Lab 4 -- Extraction

Lab 5 --

2-chloro-2-methylpropane

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Lab 6 --

Methylbenzoate

Lab 7 -- Methyl

m-nitrobenzoate

Lab 8 --

Cyclohexene

Lab 9 --

Anisalacetophenone

Lab 10 --

Identification of

Unknowns

Check-out

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Experiment Schedule

Chemistry 234 - Spring, 2002

ext: Experimental Organic Chemistry * [EOC] by J. C. Gilber and S. F. Martin. Publisheaunders, 2001, 3rd Edition

art I - Introduction to Laboratory Techniques (55 points)

Date RangeLab

Periods

Experiment Reading* [EOC] Credit

an 22 - 28 1 Check In, Melting Points 37-39, 107-111 10

an 29 - Feb 4 1 Recrystallization 88-107 10

eb 5 - Feb 11 1 Fractional Distillation 116-140 15

eb 12 - Feb 18 1 Extraction 70-73, 141-158 20

Part II - Synthesis (130 points)

Date RangeLab

PeriodsExperiment Reading* [EOC] Credi

eb 19 - Feb 25 1 2-chloro-2-methylpropane 423-427, 435-439 20eb 26 - March 11 2 methyl benzoate Syllabus 40

March 12 - 25 1 methyl m-nitrobenzoate Syllabus 25

March 26 - April 1 1 cyclohexene Syllabus 20

pril 2 - 8 1 anisalacetophenone 569-573 25

Part III - Identification of Organic Compounds (45 points)

Date RangeLab

PeriodsExperiment Reading* [EOC] Credi

pril 9 - 22 2Identification of an aldehyde,amine, alcohol or ketone

735-738, 746-748,751-767, 777-781,788-794

45

pril 23 - 29 Make-up and checkout

Note: All pages indicated in this column refer to the text book, Experimental Organic Chemistry, 3rd Edition. Before coming to lab, you are expected to read these pages indicate

bove as well as the corresponding pages in this Lab Manual.

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Hour Exams: 7:00 p.m. February 28 and April 24, 2002

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General Information

Course Objectives

Chem 234 provides you with an opportunity to learn about the properties,syntheses, separation, purification, and identification of organic compounds. Thecourse consists of lecture sessions and laboratory sessions.

In lecture sessions you learn the theory and detailed background behind certainorganic experimental techniques.

In laboratory sessions you conduct experiments designed to introduce you to avariety of these experimental techniques. Chem 234 is also designed to provideyou with the opportunity to learn how to keep the records of scientific research in alaboratory notebook, a skill which is required in many scientific fields.

You are, of course, expected to perform the assigned experiments in thelaboratory, but you are also expected to understand the principles behind theseexperiments. Near the end of the course, you will be expected to carry out thechemical syntheses of organic compounds and determine the structures of

unknowns.

xperiments

The techniques and background material for each experiment will be presented inthe weekly lecture session. You must read the appropriate text and syllabusmaterial before coming to each lecture

You will perform the experiments only in your assigned laboratory period. We

expect that you will come to each laboratory session well-prepared and ready touse your laboratory time efficiently. There are times when you may need to work ontwo different experiments in the same laboratory session, so you must plan ahead.If you miss a lab period for a valid reason (medical or a pre-approved absence),you may be able to do the experiments at another time (preferably that sameweek). However it is your responsibility to schedule these make-ups with your TAand with the Storekeeper. Unexcused absences cannot be made up and will bescored zero.

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Each new technique will be described to you in detail before you will have to use it,but thereafter you will be expected to be able to use that technique without anyfurther detailed directions. To do this, you must acquire not only good manipulativeskills in the laboratory but also a good sense about what a given procedureaccomplishes and when it should be used.

Occasionally, you may encounter difficulties with an experiment. If you areresponsible for this difficulty and require additional laboratory time and/or starting

material, a penalty of 10% of the grade for that experiment will be assessed. If,however, it is not your fault that you need extra time and/or material, no penalty willbe assessed.

ab Quiz

There is a on-line quiz associated with each experiment in WebCT. To receivecredit for the quiz it must be completed before the scheduled starting time of your laboratory section.

ChemNet LessonsChemNet lessons are available to aid in your understanding of the experiments andto make your laboratory work easier. Although you can work at these lessons anytime you wish, it is most helpful if you do the appropriate lessons shortly beforegoing to the laboratory. You will earn 2 points toward your grade for each organiclaboratory ChernNet lesson you complete.

In Chem 234 the ChemNet lessons are on the Internet. You access them throughWebCT.

To log onto ChemNet select the ChemNet icon in WebCT. Next you have to typeyour NetID and choose a secret password that you must remember. The passwordmay be the same as for your e-mail. You will be asked for this password each timeyou log onto ChemNet. The graded ChemNet lessons for Chem 234 are listedbelow (in the order you will want to complete them):

Melting PointsPhase DiagramsMixed Melting PointsRecrystallizationBoiling PointsMole FractionsB.P. of MixturesDistillation ExperimentFractional DistillationDistillation ColumnsExtractionsExtraction Experimentt-Butyl Chloride




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Chemical TestsTry Known CompoundQualitative Unknown

Getting Help:

There will be time at the end of each laboratory session to get help from your teaching assistant. In addition, TAs are available in the Chemistry Learning Center,

212 Chemistry Annex, Monday - Thursday afternoons to answer questions.

Missed Labs:

For medical or true emergency reasons we will attempt to accommodate studentswho cannot carry out their experiments at the assigned times by scheduling them todo these experiments at other times. However, to receive credit for suchexperiments, the student must inform their own TA of the rescheduling andreschedule the experiment with the storeroom manager (469 Noyes Lab) at least 2days in advance of the make-up date. Such rescheduling will only be provided for

significant medical reasons or emergency situations. More than one rescheduledlab per semester will require the written approval of the instructor in chargeof the course. Students will receive a grade of zero for labs not made-up and morethan one zero on a lab will almost certainly result in failure of the course.

Grading

The grading in Chem 234 is based upon the results of the ten experiments, the twoone-hour written exams, 10 on-line quizzes, and the 16 ChemNet lessons.

The semester of Chem 234 is divided into three parts. Part 1, Introduction toTechniques, emphasizes theory and principles. Most of the points in Part I areearned on a 50 minute written exam covering these topics.

Part II, Synthesis, emphasizes laboratory work. Most of the points in Part II areearned from the results (yields, purity, calculations) of the three experiments. PartIII, Identification of Organic Compounds, also emphasizes laboratory work, withmost of the points being based upon your ability to identify and support your identification of an unknown organic compounds.

Near the end of the semester, the second (and last) 50 minute written exam willcover the theory and practice of the laboratory experiments in Parts 11 and 111,including the applications of spectroscopy.

The points assoicated with these activities are:

Activity Points

aboratory Work 10 for a total of 230 points 230

On-line Quizzes 10@10 points each 100

0 Minute Exams 2 @ 100 pts each 200




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ChemNet Lessons 16 @ 2pts each 36

10 points for each time goggles not worn -10*n

Total 566-10*n

The grade distribution for Chem 234 will be approximately 15% A, 30% B, 50% C,and 5% D plus E. Therefore, an "average" student will receive the "average" grade

of C in this course. You must complete every experiment in order to receive at leasta grade of D.

Any requests for regrading of laboratory reports or quizzes must be submitted inwriting within one week of the day it is handed out in class. No requests will beaccepted after this time period. All laboratory reports to be regraded should besubmitted to your TA.

If you cheat on any lab (i.e., report false data for the melting points or gram yieldsof the samples you turn in), you will automatically receive a grade of zero for thatexperiment andlor an F grade for this course.

Your TA will check the melting point and gram yield of your samples.

On-line quizzes must be completed before the start of your scheduled laboratoryperiod.

aboratory Notebooks and Reports

Your laboratory notebook is the complete and permanent record of your activities inthe laboratory. Your notebook should be patterned after the form discussed in

Chapter I of the textbook. All data, observations, etc., should be entered directly into the laboratory notebook during the laboratory session. As part of your

pre-laboratory preparation, you should enter the quantities and physical propertiesof all the compounds and solvents to be used for an upcoming experiment. Your notebook will not be turned in each week, but it will be checked during the semester by your TA.

Your laboratory report is different from your laboratory notebook. Your report is acomplete and readable summary of the experiment you have just performed. Thereport is written on a sheet of paper separate from your laboratory notebook. Each

laboratory report is due one lab period after you finish the particular experiment.Laboratory reports should be turned in at the beginning of the laboratory session. Alate laboratory report incurs a penalty of 10% of the grade for that experiment. Noreport will be accepted more than two lab periods after it is due unless extenuatingcircumstances prevail.

Since your laboratory reports will be graded, you should write themlegibly, clearly, and in good English. The laboratory report should statea reference to the procedure followed and list any changes that weremade from the stated procedure. DO NOT copy the entire procedure




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into your report, as it is not expected and is a waste of time. DO includethe following items:

(1) Balanced equations for the chemical reactions,

(2) Summaries of data and yields, including the appropriate calculations,

(3) Graphs or tables, if appropriate,

(4) A discussion of errors and their possible effects upon the results of theexperiment,

(5) Answers to all assigned exercises,

(6) Anything else assigned, and

(7) Anything you feel is pertinent to a good summary of the experiment.




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Chem 234 Check-In Procedure

ou will not be charged for stocking your drawer during this initial check of its contents. Afteis, however, you will be charged for replacing any damaged or missing items. You MUST

ave the contents of your locker checked by a TA or a storeroom manager upon your rmination of enrollment in Chem 234 or your completion of this course. Failure to have yocker checked will result in a fine of ten dollars. This fine will be in addition to the charges till be made for replacing any broken or missing equipment. Finally, you are responsible foe cleanliness of your own work area. For safety reasons, keep it clean!

1. Remove the equipment in your drawer, and check it against the Equipment List.2. Return any extra equipment you find in your drawer to the storeroom manager in469 Noyes Lab.

3. Mark on the Equipment List any items you find broken or missing. Remember tocheck for "star" cracks in glassware. Make sure that your thermometer is notcracked, and that the 0-ring is inside the thermometer adapter. Also check to seethat the four indentions at the bottom of your distilling column are intact.

4. Bring your completed Equipment List to the storeroom manager in room 469

Noyes Lab. Also bring him any repairable damaged equipment for replacement. Hewill replace your damaged equipment with good items and will provide you with anyitems you have found missing. Your drawer should now have a full set of equipment as listed on the Equipment List.

5. Return all checked items to your drawer. Matches, rubber bulbs, and glassstirring rods should stay in your drawer.

6. Leave the Bunsen burner on the top of your desk. Leave the Thiele tube in theclamp provided for it above your work area. DO NOT put the Bunsen burner, Thiele

tube, or vacuum hoses in your locker. All ironware is to be kept in the bins at theends of the lab. If you use these items during a laboratory session, remember toreturn them to the proper bins at the end of the laboratory session. DO NOT putthem in your locker. All tubing (except that on the steam bath or Bunsen burner)and wire gauze should be kept in the boxes at the east and west ends of the lab.

o identify the names of equipment consult the display just inside the door or the equipmenhown below.

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hemistry 234 equipment display in 464 Noyes Lab.

Chem. 234 Equipment List

Adapter, Bent, 105° 14/20standard taper joint

Adapter, Distilling, 14/20, w/10/18 Thermometer joint

Adapter, Teflon, Thermometer,10/18 w/ O-ring

Beaker, Griffin, w/spout, 30 mL





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Beaker, Griff in, w/spout, 100 mL




Bulb, pipette, pure gum rubber

Clamps, i.e., Plastic, yellow, for 14/20 joint

Clips, Tubing, Steel (used to attach gum rubber hoses to glass

oints)

Column, Distilling, 14/20 standard taper joint.,10 x 130 mm,

Condensor, Leibig, 14/20 standard taper joint

Cylinder, pyrex glass, graduated, 10 mL




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Cylinder, poly, graduated, 50 mL

Flask, Erlenmeyer, 25 mL




Flask, Filter, 125 mL&

Flask, Pear-shaped, 14/20 standard taper joint, 25 mL




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Flask, Recovery, 14/20 standard taper joint, 25 mL



Funnel, Buchner, Porcelain, #2, 67 mm 01); Includes one

ubber stopper w/ center hole

Funnel, Hirsch, Porcelain, 4/0, 55 mm OD

Funnel, Polyethylene, 31, 4" x 4"

Funnel, Powder, P.E., 65 x 15 mm

Funnel, Separatory, 250 mL,- Includes one each #22 glass

opper & teflon stopcock. (Note: TefIon stopcock has twoO-rings. One black rubber O-ring & one white teflon O-ring)

Glass rod, 9mm x 255mm




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Holder, Test Tube

Rack, Test Tube

Spatula, Stainless Steel, double bladed

Stopper, Glass, 14/20 standard taper joint.

Test Tube, Pyrex, 13 x 100 mm

Test Tube, Pyrex, 25 x 150 Mm

Test Tube, Pyrex, 25 x 200 mm

Test tube, w/Side-arm, 25 x 200 mm

Thermometer, -100 to 260°C

Tube, Drying, Polyethylene

Wash bottle, Polyethylene, 250 mL

Watch Glass, Plain, 75 mm diameter




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LABORATORY SAFETY

ead Chapter 1, especially pp. 15-23, of the textbook before coming to your first laboratoryession. You will fill out the Safety-device Location Worksheet during your first laboratoryession.

he importance of safety precautions in a Chemistry laboratory cannot be overemphasized

he following safety rules must be followed. Use common sense when working with chemicnd laboratory apparatus. As safety is an integral part of this course, your TA will be gradingou for compliance with these safety rules.

aboratory Safety Rules

1. You must NOT be in the laboratory without a TA present. The laboratorysessions are four hours in length. You will not be allowed in lab after your labsession has ended.

2. Safety goggles for eye protection must be worn properly in the laboratory at alltimes. If you need to remove your goggles, step outside the laboratory to do so.Prescription eyeglasses (even with safety lenses) do not provide adequate eye

protection, especially from the sides. Therefore, you will be removed from thelaboratory if you are found without safety goggles covering your eyes. It is verystrongly recommended that you NOT wear contact lenses of any kind in thelaboratory. You should read the safety information on contact lenses and laboratoryaccidents posted outside the lab. Please check with your TA if you absolutely needto wear contact lenses. If you get anything in your eyes, use the eye wash stationor the eye wash faucet to wash your eyes thoroughly with plenty of water and notifyyour TA immediately.

3. Closed-toed shoes that completely cover the foot MUST be worn in the

laboratory at all times. Sandals or perforated shoes are not permitted, as brokenglass and spilled chemicals are constant hazards.

4. Shorts and short skirts (above the ankle) will NOT be allowed. Shirts/blousesshould protect the upper body. Loose clothing should not be worn. Do not wear hosirey as it will "melt" upon contact with acid and some chemicals.

5. You MUST note the location of the fire extinguishers, safety showers, eyewashes, and first-aid kits in the laboratory, so that you will know where to obtainthese items if they are needed. You will fill out the Safety-device Location

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Worksheet during your first laboratory session.

6. Many of the chemicals used in the laboratory experiments will be new to you.You should become acquainted with the properties of every new chemical you use.The Merck Index and www.chemfinder.com are good sources for finding theproperties and toxicities of many organic compounds. Access to material safetydata sheets through various web sites can be obtained on the School of ChemicalSciences Safety Resources Web Page at safety.scs.uiuc.edu. All chemicals should

be treated as though they are toxic. Compounds can enter the body by beingabsorbed through the skin, or by being inhaled or ingested. Therefore,

(a) Keep vessels covered. Put the caps back on the solvent bottlesimmediately. Never evaporate solvents other than water into theatmosphere. Wipe up any spills immediately. In order to check for anodor, hold the sample about a foot away from your face and gently fanthe vapors towards your nose. Do not put anything in your mouth.

(b) You should use the gloves that are available. Keep your bench topclean! DO NOT rub your eyes or your face without first washing your hands. If something does get into your eyes, remember to wash your eyes with plenty of water and notify your TA. You should protect your clothing by wearing a laboratory apron or lab coat. Always wash your hands thoroughly before leaving the laboratory session. If you have anycuts or scrapes, cover them with band-aids, etc., before coming to thelaboratory.

(c) To dilute acids, carefully and slowly add the concentrated acid to thewater, never the other way around. This avoids dangerous splattering.

"Do like you oughta, add acid to water".7. Never heat a closed system! Always use boiling chips when heating any liquid,even water. When heating a test tube, never point it at yourself or at anyone else.Never heat flammable solvents (i.e., anything other than water) in an opencontainer with a Bunsen burner.

When you want to use a Bunsen burner, make sure that none of your neighbors isusing a flammable solvent and that there are no flammables in the immediate area.Light the match first, then turn on the gas while holding the match close to the topof the burner. Long hair must be tied back. Do not wear garments with floppy

sleeves or loose wrist cuffs. Turn off the Bunsen burner immediately when you arefinished with it.

8. Do not use cracked or chipped glassware. Examine your glassware for "star"cracks. Broken glassware should be replaced immediately with new glassware fromthe storeroom. Do not handle broken glass with your hands. Sweep it up, or use apiece of toweling to grasp the pieces. The storeroom has leather gloves to wear while cleaning up broken glassware.

9. Only aqueous solutions (e.g., aqueous acids and bases) may be discarded down

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the drain. Flush them down with plenty of water. Other waste materials, both liquidand solid, should be disposed of into the properlabeled waste containers located inthe hoods. Broken thermometers should be put into jars located in the hoods. Askyour TA to assist you in cleaning up any spilled mercury.

10. In the case of an accident (cuts, burns, reaction to a chemical, etc.), informyour TA immediately. A limited degree of first-aid is available in the storeroom,469 Noyes Lab. If you are seriously injured, you will be taken to the medical center.

Report all accidents immediately.

Your health is more important than your grade in Chem 234!

11. Never pour chemicals directly from the storage containers directly into your reaction vessel.

12. Smoking, eating, and drinking are not permitted in the laboratory. Do not bring foobeverages into the laboratory.

13. No pets are allowed in the laboratory.

14. No "horseplay" is allowed in the laboratory.

15. No radios or CD players are allowed in the laboratory.

A good perception of your surroundings is very important in a chemicallaboratory. This state of mind requires your full attention. Take care of yourself and your neighbors. Immediately warn your neighbor if you seehim/her doing something dangerous. It is natural for you to feel somewhatconfused at times. Do not be hesitate to ask your TA or the storeroommanager for guidance with the use of the laboratory equipment or for advice

on safety matters. Please respect the fact that other students must use thecommon laboratory equipment, such as the balances, melting point apparati,hoods, etc. Take care of this equipment, and clean up your messesimmediately.

afety and Emergency Equipment In 467 Noyes Lab

The Chem 234 laboratory sessions will be held in 467 Noyes Laboratory. This labcontains the following safety and emergency equipment:

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Fire Blanket

Fire Extinguisher

Overhead Shower

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Safety shower withcurtain.

Eye-Wash Faucets

Eye wash station

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Two drench hoses.

Fire Alarm

First Aid Kit

efore you begin laboratory work in this course, you must complete the Safety Device LocaWorksheet.

ocate each of the items listed below and mark their locations on the Worksheet by using tymbols shown in the table. Indicate where your own area is located, and then indicate whee six nearest Eye-Wash Faucets are in relation to your work area.

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Quantity Equipment Symbol

13 Eye-Wash Faucets

1 Eye-Wash Station

2 Drench hoses

7 Overhead Shower

1 Safety Shower with Curtain

1 Fire Blanket

6 Fire Extinguisher

1 Fire Alarm

1 First-Aid Box

2 Exits

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ou must wear appropriate clothing in the laboratory at all times. You MUST wear your safeoggles over your eyes at all times in the laboratory! DO NOT wear loose or skimpy clothingaris, neckties, shorts, halter-tops, overly large or ragged laboratory coats). DO wear close

hoes in the lab. DO NOT wear sandals or perforated shoes. Long hair must be tied back.

or additional laboratory safety information and resources access the School of Chemicalciences Web page at safety.scs.uiuc.edu

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Experiment 1: Melting Points (10 points)

Summary

elting points are very useful in determining the purity of a compound. Throughout this clasou will measure the melting point of your products in order to assess purity. You will practicis technique on a sample of benzoic acid.

ut open end of tube inhe sample.

ape tube so samplealls to the bottom of theube.

mpure samples have lower melting points than pure solids. You can use this information toetermine the identity of an unknown through the mixed melting point method. You will beven an unknown from the list below. By determining the melting point of your unknown, yo

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ill be able to narrow the choices to three, based on the melting point ranges. You will then our unknown with EACH of the three possibilities. You can determine the melting point of ach of the mixtures. In the two mixtures that contain two different compounds, you should drastic change in the melting point since the samples are not pure. One of the samples w

ontain only one compound, and this should be reflected by the melting point.

Compound Melting Point

acetanilide 113-115 °C

p-aminobenzoic acid 188-189 °Ccamphoric acid 183-186 °C

trans -cinnamic acid 133-134 °C

malonic acid 135-137 °C

p-nitrophenol 113-115 °C

resorcinol 110-113 °C

succinic acid 187-189 °C

urea 133-135 °C

rst obtain a sample of benzoic acid from your TA (about a spatula-tip). Grind the sample infine powder, and take two melting points, one fast, one slow (2 °C/min). Obtain your unknom the stockroom, and grind this sample if necessary. Take two melting points of your kno

one fast, one slow). You should now be able to determine the three possibilities for the idenf your unknown.

ix a spatula-tip of your unknown with a spatula-tip of each of the three possible compoundhese samples should be well mixed to ensure the best results. Take the melting points of ach of the mixtures, and use this information to determine the identity of your unknown,

amples of twoompounds for mixed

melting point.




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Grind samples together.

ou should measure the melting point with the Thiele tube at your bench or the electricallyeated melting point apparatus in the lab.

hiele tube meltingoint apparatus

lectrically heated

melting pointpparatus




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. Report

Your report should include the following:

1. Reference to the procedure with any changes noted

2. Data for melting points of benzoic acid

3. Data for melting points of unknown sample

4. Data for the three mixtures

5. Identity of your unknown

6. Interpretation of data and a short conclusion

7. Use the data in figure 3.1 on page 108 of the textbook to answer thesequestions.

a. If a liquid with a composition of 80 mole % B were cooled what is the

composition of the solid that forms first?

b. If a liquid with a composition of 20 mole % B were cooled what is thecomposition of the solid that forms first?

c. If a solid with the composition 80 mole % A and 20 mole % B were heated whis the composition of the first liquid that forms?

d. If a solid with the composition 80 mole % A and 20 mole % B were heated whis the composition of the last solid to melt?

ou should complete the web-based ChemNet tutorials on melting points before coming to b.




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Experiment 2: Recrystallization (10 points)

ummary

ou will be learning several techniques for purification of organic compounds. One veryffective way to purify solids is through recrystallization. In this experiment, you will be given

mpure sample of benzoic acid that you will purify by recrystallization. You will also detennine melting point of the recrystallized benzoic acid to assess the purity.

mpure sample of enzoic acid.

enzoic acid after ecrystallization.

rocedure

he procedure for recrystallization is found in your text, page 96. You will make the followinhanges to the procedure:

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1. Scale up the procedure so that it accommodates 2 grams of benzoic acid.

2. Weigh the sample of impure benzoic acid before you begin recrystallization.

3. Skip the "Decoloration" section.

eat the sample with enoughwater to dissolve all solublematerial.

dd more water if needed.

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ilter the hot solution toemove insoluble material

oil off some of the water.

se a boiling stick when youoil off the solvent.

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e sure to use the GLASSowder funnel for your hottration rather than the plastic

unnel.

Crystals form as solution isooled.

Cool to completerystallization.

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ilter, wash, and dry theroduct.

ote: You will need a total of 40-5O mL of water for this experiment. If you add too much waou can boil some off after filtration.

Report Requirements

Your lab report should include the following:

1 . References to procedure with any changes noted

2. Weight of recrystallized benzoic acid

3. Percent recovery of benzoic acid

4. Melting point of recrystallized benzoic acid and literature melting point

5. A description of the purified benzoic acid

6. Interpretation of data and short conclusion (discuss purity, recovery, and overall

effectiveness of recrystallization)7. Answer these questions in your report:

a. Why did you do a hot gravity filtration?

b. Why did you do a cold filtration?

c. The solubility of benzoic acid in water at C° is 0.020 g/100 mL of water. If you used g of impure benzoic acid and 100 mL of water, what is the maximum yield of benzoic athat could be recovered?

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Experiment 3: Fractional Distillation (15 points)

ummary

Fractional distillation is a technique used to separate volatile compounds withboiling points that differ by less than 50° C. In this experiment, you will distill amixture of methanol (b.p. 65°C and water (b.p. 100°C). Using data obtained in thisexperiment, you will graphically demonstrate how head temperature changes withthe composition of the distillate.

rocedure

Obtain 60 mL of a sample of one of the methanol/water mixtures from the carboysin the lab. Record which sample you chose (A, B, or Q). Add the mixture and a fewboiling chips to a clean 100 mL round bottom flask. Set up the apparatus for fractional distillation as demonstrated in lab.

se the Thermowell toeat the flask.

lug it into the Variacn your bench.

o not plug directly inhe wall outlet.

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se a distilling columno help separate the

mixture.

he thermometer

dapter allows you tout the thermometer nto the distillingdapter.




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se joint clamps andose clamps.

ere is the completedpparatus.

Have your set-up approved by your TA before you begin.

Begin heating the sample on a low setting and increase the temperature asneeded. Collect the distillate in a graduated cylinder. Record the head temperaturewhen you collect the first drop of distillate, and then record the head temperature atevery two milliliters of distillate collected. Stop the distillation when you haverecorded three readings at about 100°C, even if you haven't distilled all of thesample.

DO NOT heat the flask to dryness.




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Report

Your report should include the following:

1 . References to procedure with changes noted

2. Table of recorded data (volume collected and head temperature)

3. Graph of distillation data: Make a plot with the head temperature on the y-axis and volume of distillate on the x-axis (see page 125 of your text). Draw an AVERAGE linethrough the data points. DO NOT simply connect the dots.

4. Summary table of data: Use your graph to determine the volume and boiling pointrange of each "fraction." Make a table that includes Fraction number, collected volumeand boiling range. Here is a sample table structure.

5. Interpretation of data and conclusion, including the methanol/water ratio of your sample.

Answer these questions in your report:

1. Sketch and label the apparatus you used for a fractional distillation.

2. Using figure 4.3 on page 125 of the textbook, if a mixture has 60 mole % toluene an40 mole % benzene:

a. At what temperature will the solution start to boil?

b. What is the composition of the first small amount of vapor that forms?

c. If the vapor formed in question 2b is condensed and the resulting liquid heated to its




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boiling point what is the composition of the new vapor?

utorials

You should work the web-based ChemNet tutorials on distillation before going tothe lab.




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Experiment 4: Extraction (20 points)

ummary

Extraction is a technique used to separate and/or purify compounds. In thisexperiment, you will be separating a mixture of anthracene, p-nitroaniline, andbenzoic acid into the individual components based on their differing solubilities inimmiscible phases.

Mixture of anthracene,-nitroaniline, and benzoic acid.

urified benzoic acid

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urified anthracene

urified p-nitroaniline

relab

BEFORE class, prepare a flow chart that outlines every step of the experiment. Theflow chart should show a branch point at every extraction step (including isolation of the three compounds), and you should note which compounds are in each layer ateach step. You must have this flow chart completed before you will be allowed to

begin the experiment,and the flow chart will be handed in with your lab report.

rocedure

Be sure to wear rubber gloves when doing this experiment.

Obtain a mixture of benzoic acid, p-nitroaniline, and anthracene. Weigh the mixture,and then dissolve the mixture in 75 mI, of methylene chloride. If some solid doesn'tdissolve after several minutes of stirring, filter the solution. Add the solution to the




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separatory funnel and proceed through the following steps:

irst Period:

1 . Add 50 mL of 3M HCI to the separatory funnel. Shake and vent the funnel asdescribed in the textbook readings.

Be sure to vent the separatory funnel to avoid pressure build up. If you get hydrochloracid on your skin be sure to wash with large amounts of water. Contact your TA for assistance.




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2. Allow the layers to separate in the funnel. Drain the bottom layer into a flask labeled"organic," and pour the top layer into a flask labeled "acidic extract"

3. Return the organic layer to the separatory funnel, and repeat steps 1 and 2. Add thetop layer from this extraction to the flask labeled "acidic extract".




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4. Place the organic extract into the separatory funnel, and add 50 mL of 3M NaOH.Shake and vent the separatory funnel as before.

If you get sodium hydroxide solution on your skin be sure to wash with large amounts water. Contact your TA for help.

5. Allow the layers to separate. Drain the bottom layer into a flask labeled "organic," apour the top layer into a flask labeled "basic extract."

6. Return the organic layer to the separatory funnel, and repeat steps 4 and 5. Add thetop layer from this extraction to the flask labeled "basic extract."

7. Cool the ACIDIC EXTRACT in an ice bath. Basify the ACIDIC EXTRACT with 6MNaOH (calculate how much you need). Check the pH of the solution with pH paper tomake sure it is BASIC. Filter the resulting precipitate by vacuum filtration. Place the soon a piece of filter paper, and allow it to air dry until the next lab period.

USE CAUTION IN HANDLING THE SODIUM HYDROXIDE.

8. Cool the BASIC EXTRACT in an ice bath. Acidify the BASIC EXTRACT with 6M HCCheck the pH of the solution with pH paper to make sure it is acidic. Collect the resultsolid by vacuum filtration. Place the solid on a piece of filter paper and allow it to air duntil the next lab period.

9. To the ORGANIC layer, add a few spatula tips of Na2S04 to dry the organic layer.

Allow the solution to stand for 10 minutes.

10. Filter the solution through fluted filter paper into an Erlenmeyer flask. Evaporate thmethylene chloride using the apparatus that will be demonstrated in lab.




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econd Period:

1. Obtain weights of benzoic acid, p-nitroaniline, and anthracene and melting points obenzoic acid and p-nitroaniline.

2. Place all solids in tared, labeled vials, and give them to your TA.

Report Requirements

Your report should contain the following:

I . Reference to procedure with changes noted

2. Flow chart described above. Draw structures of all species. Show ionic structures wappropriate.

3. Weights of all three solids. Descripte their physical properties.

4. Melting points of benzoic acid and p-nitroaniline (both weights and melting points




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should be reported in tabular form).

5. Describe the solids

6. Interpretation of data and conclusion

-How pure are the extracted compounds?

-How could you purify them further?

-What was the composition of the original mixture, i.e., the ratio of benzoicacid: p-nitroaniline: anthracene?

- recovery

nswer these questions in your report:

If you have 10 grams of A in 100 mL of water and extract 3 times with 50 mL of ether whae total yield of A in the combined ether solutions? Assume the distrbution coefficient for A0. Show all of your work.

What physical property determines which layer is on the top in an extraction?

How would you extract N,N-dimethylaniline from methylene chloride into water?

How would you extract p-nitrobenzoic acid from methylene chloride into water?




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Experiment 5: Preparation of 2-chloro-2-methylpropane (20 points)

ummary

the experiment, you will be preparing 2-chloro-2-methylpropane from 2-methyl-2-propanoa an SN1 reaction.

rocedure

ou will follow the procedure from the text (pages 435-439). Note that you will be using-methyl-2-propanol instead of 1-methyl-2-butanol. However, all other reagents remain theame. You should double all quantities listed in the procedure.

hake the t-butyl alcohol with HCl.

e sure to vent the separately funnel to avoidressure build up.

you get hydrochloric acid on your skinwash immediately with large amounts of

water. Contact your TA for assistance.

eparate, wash, and dry the t-butyl chloride.

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he crude t-butyl chloride is washed to removexcess acid.

dd the sodium bicarbonate solution slowly tovoid rapid formation of CO2 as shown here.

etup for distillation of he t-butyl chloride.

Collect the product in aooled, tared container.




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se joint clamps on theondenser and hose

amps on the water nes.

Report Requirements


1 . Reference to the procedure with changes noted

2. Equation of the reaction showing structures of reactants and products. Below eachreactant, list the molecular weight, and amount used in grams (or mLs) and moles. Beeach product, list the theoretical yield in grams and moles. Give the density and boilin

point of liquids.

3. Mechanism of the reaction: use arrows to show electron movement; include allintermediates and side reactions

4. Calculation of the theoretical yield

5. Weight of product and description including color

6. Boiling range of the product

7. Interpretation of data and conclusion. Give chemical and physical reasons for notobtaining a 100% yield.

8. Answer the following questions in your report.

1. Washing the crude t-butyl chloride with aqueous sodium bicarbonate resulted in gaevolution. Write a balanced equation for this reaction.

2. Could anhydrous NaOH be used to dry the t-butyl chloride instead of sodium sulfate




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3. Write the mechanism for the reaction of n-butyl alcohol with HCl and compare it to treaction of t-butyl alcohol with HCl.




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Experiment 6: Preparation of methylbenzoate(40 points)

Summary

In this experiment you will prepare methylbenzoate by reacting benzoic acid withmethanol using sulfuric acid as a catalyst. Since this is a reversible reaction, it willreach an equilibrium that is described by the equilibrium constant, Keq .

In this experiment, you will isolate the product, methyl benzoate and any unreactedbenzoic acid. Using this data, you will calculate the equilibrium constant for thereaction as described in part III.

. ProcedureFirst Period

Obtain a 10g (0.082 mol) sample of benzoic acid fromhe storeroom (weigh the benzoic acid to obtain anxact weight before you begin). Add to it 0.62 mol of

methanol in a 100 mL round-bottomed flask.

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Cautiously, add 3 mL concentrated H2S04 down the

de of the flask. After gently swirling the contents of he flask, attach a reflux condenser and reflux the

mixture for about 60 min.

ulfuric acid causes acid burns on the skin. If youet some on your skin be sure to wash with largemounts of water. Contact your TA!

Allow the solution to cool. Add 50 mL of water to a separatory funnel, then add thecontents of the flask. The flask should then be washed with 40 mL of dichloromethane (CH2Cl2) and the washings transferred to the separatory funnel.

Use the separatory funnel to extract the ester into the CH2Cl2 (organic) layer.

Wash sequentially with 25 mL water and 25 mL 0.6M sodium bicarbonate*

(Caution, CO2 will be given off with effervescence).

After shaking and venting the funnel, remove the sodium bicarbonate layer and testto see if it is basic. Then wash the organic layer with NaCl (salt) solution, separatethe organic layer and dry with anhydrous magnesium sulfate. Remove the MgS04by gravity filtration, and concentrate the solution using the same apparatus used toremove CH2Cl2 from anthracene in Experiment 4.

*The aqueous layer from the sodium bicarbonate wash should be acidified withconcentrated HCl The unreacted benzoic acid should precipitate. Remove the

solvent by vacuum filtration. Collect and dry the solid benzoic acid and let it air-dryin your drawer until the next lab period.

Second Period

Distill the crude methyl benzoate (b.p. 199°), collecting anything that boils between170°C and 200°C. Weigh the sample of methyl benzoate and determine the yield.Weigh the sample of recovered benzoic acid. Place both samples in labeled vials,and give them to your TA.




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Caution:

1. Methanol is flammable and toxic

2. Dichloromethane is toxic

3. Handle concentrated H2SO4 and HCl with great care

4. Vent the separatory funnel frequently after swirling and subsequent shaking.CO2, gas is evolved and will build up pressure in the funnel.

I. Calculation of the Equilibrium Constant, Keq.

Calculate a value for the equilibrium constant Keqbased upon your weight of

recovered benzoic acid. In addition, calculate the percent yield of your synthesisbased upon the amount of starting benzoic acid used, and another percent yieldbased upon the amount of benzoic acid that actually reacted (as determined by theweight of recovered benzoic acid).

Calculation of the Equilibrium Constant Keq:

Since the volume of the reaction mixture is the same for each component, we can




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use moles instead of molarities as the units in our Keq expression. Let Bi = initial

moles of benzoic acid, let Mi = initial moles of methanol, and let X = final moles of

methyl benzoate produced at equilibrium.

Based upon the stoichiometry of equation 1, we can conclude three things about X,namely that X = final moles of water produced at equilibrium, X = moles of benzoicacid consumed when equilibrium is established, and X = moles of methanolconsumed when equilibrium is established. Using our definitions, equation 2

becomes:

We know Bi and Mi. All we need to do before we can calculate Keq is to Put X in

terms of something known, like the amount of benzoic acid recovered. Let Bf = final

moles of benzoic acid present at equilibrium. Thus Bf = Bi - X, or X = Bi - Bf .

Substituting(Bi - Bf ) for X in equation 3 gives:

We can now calculate Keq by entering the appropriate values of the moles of

benzoic acid used (Bi), the moles of methanol used (Mi), and the moles of benzoic

acid recovered (Bf ) into equation 5.

Calculation of the % Yield based upon initial amount of benzoic acid used:

Let E = moles of methyl benzoate ester obtained. Note that this calculation is valid

only if benzoic acid is the limiting reagent.




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Calculation of the % Yield based upon amount of benzoic acid that is consumed:

V. Report Requirements

Your lab report should contain the following information:

1 . Reference to procedure with any changes noted

2. Equation of the reaction showing structures of reactants and products.

Below each reactant, list the molecular weight, and amount used in grams (or mLs) and moles. Below each product, list the theoretical yield in grams andmoles.

3. The complete mechanism showing all intermediates and arrows todemonstrate electron movement

4. Flow chart for the isolation of methyl benzoate and unreacted benzoic acid

5. Weight of recovered benzoic acid

6. Weight and boiling point of methyl benzoate

7. Calculations

a. percent yield based on amount of benzoic acid with which youstarted

b. percent yield based on amount of benzoic acid consumed

c. Calculate the equilibrium constant two ways and compare theresults.

8. Interpretation of data and conclusion. Explain what was done in thisexperiment to drive the reaction toward ester formation.

9. Answer these questions in your report:

1. How is sulfuric acid involved in the formation of methylbenzoate?

2. Write a balanced equation for the formation of ethyl acetate




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from ethanol and acetic acid.

3. Using K=3.0, calculate the number of moles of methyl benzoatewhich could be formed from 0. 1 mol of benzoic acid and 0.3 molof methanol.




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Experiment 7:Preparation of methyl-m-nitrobenzoate (25 points

Summary

In this experiment, you will synthesize methyl-m-nitrobenzoate from methylbenzoate via electrophilic aromatic substitution. The isolated product will be purifiedby recrystallization, and purity will be determined from the melting point.

II. Procedure

Bring a clean, dry 25 x 150 mm test tube to the storeroom manager and trade it infor a 6.2 mL (6.8 g, 0.050 moles) sample of methyl benzoate (weigh the samplebefore you begin to obtain an exact weight). Place 14.5 mL (26.7 g) of concentratedsulfuric acid in a 125 rnL Erlenmeyer flask, cool it to 0 °C in an ice/water bath, thenadd all of the methyl benzoate with swirling.

Separately, prepare a mixture of 5.0 ml- (9.2 g, 0.094 moles) of concentratedsulfuric acid and 5.0 mL (7.1 g, 0. 113 moles) of concentrated nitric acid.

Cool the nitric acid in an ice bath and then very slowly add the sulfuric acid keepingthe mixture cold.

Be very careful in handling the concentrated sulfuric acid and nitric acid. If you get acid on you be sure to wash with large amounts of water and contactyour TA immediately for assistance.

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When it has cooled, add this cold

cid mixture dropwise over 5minutes to the methyl benzoateolution, which is kept swirling inhe ice bath.

fter the addition is complete,llow the reaction mixture to stand

t room temperature for andditional 10 minutes, swirling itccasionally.




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our the mixture, with stirring,ver about 150 cc of crushed ice.

Collect the solid precipitate byuction filtration, and wash ithoroughly with water to removeny traces of acid.

Recrystallize your product from a

mall amount of methanol.Collect the crystals by vacuum

tration and wash with a smallmount of COLD methanol.

Allow the product to air dry in your drawer until the next lab period. Obtain theweight and melting point of your dry product. Give your sample to your TA.

I. Report Requirements

Your report should contain the following information:




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1. Reference to the procedure with changes noted

2. Equation of the reaction showing structures of reactants and products. Below eachreactant, list the molecular weight, and amount used in grams (or mLs) and moles. Beeach product, list the theoretical yield in grams and moles

3. Mechanism of the reactions showing the structures of intermediates and arrows todemonstrate electron movement

4. Experimental yield and percent yield (show calculations)

5. Color and physical properties of your product

6. Melting point of product

7. Give chemical and physical reasons for not obtaining 100% yield. Write equations fside reactions and explain how side products were removed from the product.

8. Interpretation of data and conclusion.

9. Answer these questions in your report:1. Draw all resonance structures for the nitration of methyl benzoate occurring at theortho, meta, and para positions. Be sure to include all charges.

2. Circle any resonance structures that demonstrate why the ortho-para positions areunfavorable sites for nitration.




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Experiment 8: Dehydration of Cyclohexanol

Summary

In this experiment, you will synthesize cyclohexene via acid-catalyzed dehydrationof cyclohexanol. This reaction will be carried out by heating the components andcollecting impure product. A second distillation will be necessary to purifycyclohexene. Purity will be determined by the boiling point of the collected product.The product will be tested for unsaturation using the Baeyer test.

. Procedure

Bring a clean, dry 25 x 150 mm test tube to the storeroom manager, and trade it for a sample of cyclohexanol. Obtain a weight or volume for the sample (around 14.2gor 15 mL). Be sure to use the mass of your sample for all of your calculations. Intoa 50 mL round bottom flask, add the cyclohexanol, 9 M sulfuric acid (7.5 mL), and afew boiling chips. Mix the contents of the flask with gentle swirling.

quip the flask for fractionalistillation (see experiment 3).

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se a heating mantle withand to heat the distillationask.

Use an erlenmeyer flask as the collection vessel, and cool it in an ice bath duringthe distillation. Heat the reaction mixture, and collect all distillates while maintaining

a head temperature in the range of 80-85 °C. Discontinue the reaction once about 5mL remains in the distillation flask.

water separates as a distinct layer,emove it with a pipet.

dd several spatula-tips full of

otassium carbonate to the cruderoduct in the Erlenmeyer flask. Swirlhe mixture occasionally over a 10-15

minute period, and add moreotassium carbonate IF the liquidemains cloudy.

horough drying is very important (why?).Transfer the product to an 25 mL round bottomedask by decanting or using a pipet.




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dd a few boiling stones to theask, and purify the product bymple distillation. Use a taredal as a receiver, and cool the

eceiver in an ice bath.

Collect distillate with a head temperature between 80-85 °C. Obtain a weight of your purified product. Note: If product is cloudy, add several spatula-tips full of potassium carbonate to the vial, and transfer the dried product to another tared vial

by pipet before weighing.

Bayer Test for Unsaturation:To test your product for unsaturation, follow the procedure on pages 653-654 of your lab text for the Baeyer test. Perform both the test and the blank.

I. Report Requirements

Your report should contain the following information:

1. Reference to procedure with changes noted.

2. Equation of the reaction showing structures and products. Below each reactant,list molecular weight, amount used in grams (or mL) and moles. Below eachproduct list the molecular weight and theoretical yield in grams and moles.

3. Mechanism of the reaction showing structures of intermediates and arrows todemonstrate electron movement.

4. Experimental yield and percent yield (show calculations)

5. Weight of product.

6. Boiling point range of product.

7. For the Baeyer test, include both the equation for the reaction and your resultsfor cyclohexene and the blank.

8. Interpretation of data and conclusions




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1. Write the mechanism for the dehydration of cyclohexanol with sulfuric acid.

2. Why was it necessary to dry the crude cyclohexene before the final distillation?

3. Write the equation for the addition of bromine to cyclohexene. Show thesterochemistry of the product.




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Experiment 9:

Preparation of trans-p-Anisalacetophenone(25 points)

Summary

this experiment, you will be preparing trans-p-anisalacetophenone (m.p. 77-78°) from p-anisaldehyde etophenone via a crossed aldol condensation. The product will be purified by recrystallization, and purll be assessed by taking the melting point of the product.

Procedure

Follow the procedure found on pages 572-576 in your text (omit the "Analysis" portion of theprocedure. You will need to scale the procedure to six times that listed in the text. Take a clean,dry 25 x 150 mm. test tube to the storeroom manager and trade it in for a sample of p-anisaldehyde. Weigh the sample before you begin the experiment, and adjust the amount of acetophenone accordingly. Once you have obtained the recrystallized product, allow the product

to air-dry in your drawer until the next lab period. Obtain the weight and melting point.

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ocate starting material

easure reactants

ix




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et stand

Use an erlenmeyer instead of

beaker)

lter crude product

ecrystallize

Use an erlenmeyer instead of beaker)




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urified product

. Report Requirements


1. Reference to procedure with changes noted.

2. Equation of the reaction showing structures of reactants and products. Below each reactanlist the molecular weight, and amount used in grams (or mLs) and moles. Below each produc

list the theoretical yield in grams and moles.

3. Mechanism of the reactions showing the structures of intermediates and arrows todemonstrate electron movement

4. Mass of product and physical properties

5. Percent yield (show calculations)

6. Melting point of product (include literature melting point)

7. Interpretation of data and conclusion, including detailed error analysis


1. Write the mechanism for the condensation of acetophenone with itself.

2. Write the mechanism for the Cannizzaro reaction of anisaldehyde.

3. Why is the product trans-anisalacetophone instead of cis?




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Experiment 10: Identification of an Aldehyde,Amine, Alcohol, or Ketone (45 points)

Summary

In this experiment you will be given an unknown that is either an aldehyde, ketone,amine or alcohol. The possible unknowns are listed in tables in the lab. You will be

given IR and NMR spectra to help you determine the functional group and structureof your compound. You will also obtain the boiling point or melting point of your compound, perform classification tests, and make a derivative.

. Procedure

The week before this experiment begins, you will receive IR, 1H NMR, and 13CNMR spectra of your compound.

BEFORE the first day of this experiment, make a tentative functional groupassignment. You do not need to determine the structure of the unknown beforeclass, but you will need to analyze you spectra for structural information at somepoint during the course of the experiment. During the class periods assigned for this experiment, do the following in the order listed:

1. Distill your unknown, if it is a liquid, to obtain aboiling point of the pure compound.

If your unknown is a solid, take a melting point.

To obtain a boiling (or melting) point range, subtract 10°C from theobserved temperature to get a lower limit, and add 10° to the observedtemperature to get an upper limit.

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2. Perform all three of the following classification tests.

You should first perform these tests on the provided known compounds for comparison.

A. DNP - follow theprocedure onpages758-759 of your book.

B. Ceric nitrate test -follow the procedure onpage 783 of your text.

C. Test for pH - If your compound is water-soluble, use pH paper totest an aqueous solution of your unknown. An amine, since it is basic,will have a high pH. If your unknown is not water-soluble, dissolve theunknown in an ethanol-water mixture, and test the pH.

3. Make a derivative

Once you have determined the functional group present inin your unknown, choose the appropriate derivative from the list below:

Aldehyde/ketone: 2,4-DNP (pg 765-766) Alcohol: 3,5-dinitrobenzoate (780-781, Method A, see Note 1 for amounts of




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reagents) Amine: benzenesulfonamide (pg 793-794) or benzamide.

II. Lab Report Requirements

Your lab report (due the day scheduled for check-out) should contain the following:1. Reference to the procedure of EACH chemical test and the derivative2. Melting/boiling point of the unknown3. Results of each chemical test and your interpretation of the results. Writechemical equations for the tests.

4. Data table for 1H NMR (see example)

5. Data table for 13C NMR: For each relevant peak, report the chemical shift andassignment.

6. Data table for IR (assign bands above 1500 cm-1): For each band, report position(in wavenumbers), a description of the band (strong, medium, or weak; sharp or broad), and your interpretation7. Type of derivative and the melting point (include the reference melting point).Write chemical equations for the formation of each derivative.8. Identification of the unknown with a THOROUGH explanation of how you arrivedat this conclusion. Draw the STRUCTURE of your unknown.

Notes:1. Preparation of the 3,5-dinitrobenzoate derivative (amounts):0.5g 3,5-dinitrobenzoylchloride (this will be preweighed and available fromthe storeroom)1.5mL of your unknown alcohol20 drops of pyridine (Caution! Pyridine should be used in the fume hoodsince it has a VERY unpleasant odor. Do not pour pyridine or filtrates containing pyridine down the drain)

EXAMPLE 1H data writeup

Spectrum




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Label hydrogens

Make table




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Chem 234 Check-Out Procedure

ny student who fails to be checked out of the lab by a TA or by a storeroom manager will bharged with a fine of ten dollars. This fine is assessed in addition to the charges that are ma replace any broken or missing equipment.

1. Remove all equipment from your drawer and wash each item with Tetrox and water.

2. Place new blotter paper lining in your drawer.

3. Check your equipment against the Equipment List. Return any extra equipment to thstoreroom and replace any missing or broken items with new ones from the storeroom

4. Place all ironware (except the metal stand) in the bins at the ends of the lab.

5. Place all tubing (except that on the steam baths and Bunsen burners) and wire gauztheir proper storage boxes located at the east and west ends of the lab.

6. All matches, rubber bulbs, and stirring rods should be left in the drawer.

7. Leave the rubber stoppers on the Hirsch and Buchner funnels. Throw out any corkstoppers.

8. Make sure that the four indentations at the bottom of your distilling column are intact

9. Make sure that your thermometer is not cracked and that the O-ring is still inside thethermometer adapter.

10. Remove the calcium chloride from inside the drying tube.

11. Remove any stopcocks and stoppers from the separatory funnels. Tie them to thefunnels with string.

12. Place all the cleaned equipment back into your drawer. Your drawer should now haa full set of equipment as listed on the Equipment List.

heckoutchem234

experiment practical

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