cneronis - semimicro and macro organic chemistry laboratory manual

SEMIMICRO
AND
MACRO
ORGANIC
CHEMISTRY
BY
THE SAME AUTHOR
ORGANIC CHEMISTRY
SEMIMICRO AND MACRO ORGANIC CHEMISTRY
SEMIMICRO
AND
MACRO
ORGANIC
CHEMISTRY
A LABORATORY MANUAL
BY
Nicholas
D.
Cneronis
CHICAGO CITY COLLEGES
NEW YORK
•
THOMAS
Y.
CROWELL COMPANY
COPYRIGHT,
1942,
BY
THOMAS Y. CROWELL COMPANY
All rights reserved. No part of this book may be
reproduced in any form, by mimeograph or any

other means, without permission in writing from
the publisher.
FIRST PRINTING, SEPTEMBER 1942
MANUFACTURED IN THE UNITED STATES OF AMERICA
BY THE COLONIAL PRESS INC., CLINTON, MASS.
PREFACE
The present laboratory manual was developed primarily to pro-
vide suitable experiments in elementary laboratory practice for all
levels of students, both the average and the exceptional. Impressed
by the possibilities of the semimicro technic in connection with this
problem, the author began several years ago to experiment with it
in his classes. After mature consideration and six years of trial and
error with all types of students, he believes that it is possible to
attain all the objectives of laboratory practice in elementary or-
ganic chemistry using the semimicro technic. In addition, this
method offers the following advantages over the traditional
method: (1) it permits better adaptation of the laboratory work to
the varying needs of students; (2) it teaches students greater
care,
cleanliness, and manipulation; (3) it is more economical; and
(4) it reduces substantially the seriousness of possible accidents
since the quantities of reagents and size of equipment are only
some 10 to 20 per cent as great as with macro methods.
It is realized, however, that a sudden and complete shift from
traditional macro methods is usually not practical or desirable.
For this reason, in practically all experiments, semimicro is par-
alleled with the macro method. In this manner teachers may ex-
periment as widely with semimicro technic and with whatever
students they wish.
The arrangement of the material in the manual is made accord-

ing to the following plan: In the first part an attempt is made to
introduce the students to the elementary technics, such as crystal-
lization of solids, distillation of liquids, determination of boiling
and melting points and of refractive indices, necessary for the
study of organic chemistry. This is followed by a study of the
preparation and properties of the simpler groups of organic com-
pounds. The preparation of one or more compounds from each
group serves to illustrate the general principles involved. This is
followed by a systematic study designed to illustrate important
group properties and variations of these among members of the
same group. Beginning each experiment there is a brief introduc-
tory explanation relating the material of the experiment to the
previous knowledge of the student and also orienting him to the
work to be done. For each group of organic compounds there are
vi PREFACE
usually listed several preparations. It should be emphasized that
this practice does not place a premium on the amount of work
done; it is rather the organization and understanding of the work
done that are of primary importance. It is believed, however, that
directions for several preparations will be an aid to the teacher in
providing suitable work for students of different abilities and in-
terests. A number of experiments are well adapted to discussion-
demonstrations to be given by the instructor, and are so marked.
The latter part of the manual is devoted to compounds of greater
complexity. Some of these require the preparation of several com-
pounds which are used in the subsequent work in order to obtain
the final product. Thus it is hoped that the manual achieves unity
and organization for teaching rather than being a mere collection
of unrelated preparations.
The author wishes to acknowledge his indebtedness to those who

have aided him in this work: for suggestions, reading, and com-
menting on parts of the manuscript, to Louis Sattler of Brooklyn
College, Joseph B. Niederl of New York University, Gordon
Pritham of the University of Scranton, Ernest R. Kline of the
University of Connecticut, Louise Wendt of Nebraska State
Teachers College, John Entrikin of Centenary College, and to his
colleagues, Sebastian Durban, James Parsons, and Conrad Ronne-
berg; to Joseph Drummond and Kurt Spitzmueller for many sug-
gestions on apparatus and methods; to Milton Cooper and Michael
Savoy for suggestions on the experiments for the determination of
melting points; to his former students, Peter Arvan, Herman
Teifeld, Alford Anderson, Richard Erhardt, and Carl Anderson
for their patience and work in adapting the various preparations
of organic compounds to the semimicro technic; to Walter Bur-
fischer of Wilkens-Anderson Company for the many suggestions
and help in the development of the semimicro apparatus; and, for
assistance in the preparation of the manuscript, to Harold Wood-
son, Helen Karagianes, and Denver Cummings.
NICHOLAS D. CHERONIS
CONTENTS
BXPEBIMENT FAQS
General Information
1
PART
I
INTRODUCTION
TO
LABORATORY METHODS
1.
The

Sources
of
Organic Compounds
21
2.
The
Purification
of
Solid Organic Compounds
by
Crys-
tallization
24
3.
Determination
of
Melting Points
41
4.
Determination
of
Melting Points
of
Mixtures
53
5.
The
Purification
of
Organic Compounds

by
Distillation
57
6. Purification
by
Fractional Distillation
65
7.
Micro Determination
of
Boiling Points
78
8. Determination
of
Refractive Indices
82
9. Identification
of
Elements
in
Carbon Compounds
. . 87
PART
II
PREPARATION
AND
PROPERTIES
OF
SIMPLE ORGANIC COMPOUNDS
10.

Preparation
of
n-Decane
and
n-Octane
97
11.
Preparation
of
Ethylbenzene
103
12.
Preparation
of a
Hydrocarbon
by
Decarboxylation
of an
Organic Acid
106
13.
Unsaturated Hydrocarbons: Preparation
of
Cyclohexene
and Amylene
108
14.
The
Preparation
of

Acetylene
118
15.
The
Study
of
Aromatic Hydrocarbons
121
16.
Preparation
of
Hydrocarbons
by the Use of the
Grignard
Reagent
123
17.
The
Reactions
of
Hydrocarbons
127
18.
Preparation
of
Butyl Chlorides
. 131
19.
Preparation
of

Butyl Bromides
135
20.
Preparation
of
Alkyl Iodides
138
21.
Preparation
of
Bromobenzene
140
22.
The
Properties
and
Reactions
of
Halogen Compounds
. 144
23.
Grignard Synthesis
of
Carbinols
146
24.
The
Reactions
of
Hydroxy Compounds

150
vii
viii CONTENTS
EXPERIMENT PAGE
25.
Preparation of Ethers 153
26.
Preparation of Amines by Ammonolysis 160
27.
Preparation of Aniline 163
28.
Reactions of Amines 174
29.
Preparation of Nitro Compounds 178
30.
Important Reactions of Nitro Compounds 181
31.
Oxidation of Alcohols to Aldehydes and Ketones . . 183
32.
Preparation of Acetaldehyde 187
33.
The Preparation of Cyclopentanone 189
34.
Reactions of Aldehydes and Ketones 191
35.
The Polyhalogen Compounds 196
36.
Preparation of Acids by Oxidation of Alcohols . . . 199
37.
Preparation of Acids by Carboxylation of the Grignard

Reagent 201
38.
Reactions of Carboxylic Acids 204
39.
Preparation and Properties of Esters 207
40.
Preparation and Properties of Acyl Chlorides . . . 211
41.
Preparation and Properties of Amides 216
42.
Preparation of Acid Anhydrides 219
PART III
PREPARATION AND PROPERTIES OF COMPOUNDS
OF GREATER COMPLEXITY
43.
Preparation of Chloroacetic Acid 223
44.
Preparation of a-Bromopropionic Acid 230
45.
Distillation under Reduced Pressure 232
46.
Determination of Optical Rotation 244
47.
Esters of Polyhydroxy Compounds 248
48.
Properties of Carbohydrates 252
49.
Preparation and Properties of Urea 257
50.
Preparation and Properties of a-Amino Acids . . . 260

51.
Properties of Proteins 263
52.
Preparation of Substituted Anilines 266
53.
Preparation of Diazonium Salts 271
54.
Replacement of the Diazo Group by Iodine 275
55.
Replacement of the Diazo Group by Chlorine . . . 277
56.
Replacement of the Diazo Group by a Hydroxyl Group 280
57.
Reduction of the Diazo Group 282
58.
Preparation of Azo and Diazoamino Compounds . . 285
59.
Preparation of Sulfonic Acids 289
60.
Preparation and Properties of Quinones 293
61.
Preparation of Aromatic Hydrocarbons by the Friedel-
Craf ts Reaction 296
62.
Preparation of Ketones by the Friedel-Crafts Reaction 300
CONTENTS ix
EXPEBIMENT PAGE
63.
Preparation of o-Benzoylbenzoic Acid 303
64.

Preparation of Anthraquinone by Ring Closure . . . 305
65.
Condensations of Carbonyl Compounds 307
66.
The Benzidine Rearrangement 311
67.
Preparation of Heterocyclic Compounds 314
68.
Physiologically Active Compounds 317
69.
Preparation of Dyes and Indicators 328
70.
Synthetic Polymers 343
Appendix
I. Laboratory Accidents and First Aid 347
II.
Suggested List of Apparatus for Elementary Or-
ganic Chemistry (Macro and Semimicro) . . 350
III.
List of Chemicals and Reagents 352
IV. Calibration of Thermometers 355
V. Freezing Mixtures 357
VI.
Drying Agents for Organic Liquids 357
VII.
Cleaning Solutions 358
VIII. Preparation of Pipettes and Pipette Droppers . 359
IX. Preparation and Sealing of a Bomb Tube . . 360
X. Densities and Percentage Compositions of Vari-
ous Solutions 362

XL Vapor Pressures of Various Organic Substances . 367
XII.
Reference Books for Beginners in Practical Or-
ganic Chemistry and Laboratory Methods . 368
XIII. Write-Up of a Typical Experiment 369
Index 371
LIST OF ILLUSTRATIONS
FIGUHE PAGES
1.
Macro apparatus commonly used in elementary organic
chemistry 8
2.
Semimicro apparatus recommended for elementary or-
ganic chemistry 12
3.
Apparatus for experiment on the products obtained by
the carbonization of coal 22
4.
Flask with reflux condenser for heating liquids 29
5.
Semimicro apparatus for heating under reflux 30
6. Macro apparatus for ordinary filtration 31
7.
Semimicro apparatus for filtration 32
8. Method for preparation of fluted filter paper 33
9. Funnel for hot filtration 34
10.
Macro apparatus for filtration, using suction 35
11.

Semimicro apparatus for suction filtration, using funnel
made by student 36
12.
Semimicro apparatus for filtration, using ordinary funnel
and perforated porcelain disc 37
13.
Vapor pressure of naphthalene 42
14.
Effect of addition of biphenyl on the melting point of
naphthalene 43
15.
Melting-point-composition diagram of naphthalene and
biphenyl, involving formation of eutectic 44
16.
Melting-point-composition diagram involving compound
formation 45
17.
Melting-point-composition diagram involving solid so-
lutions 46
18.
Heating bath (beaker) for determination of melting
points 48
19.
Heating bath (flask) for determination of melting points 49
20.
Modified Thiele heating bath for melting-point determi-
nation 49
21.
Melting points of three mixtures of /3-naphthol and an
unknown (/3-naphthol and unknown being the same) 54

22.
Melting points of five mixtures of variable amounts of
jS-naphthol and an unknown (/3-naphthol and unknown
not being the same) 55
23.
Vapor-pressure curves of water, ethyl alcohol, and ether 58
24.
Macro apparatus for simple distillation 61
25.
Semimicro apparatus for distillation 63
XI
xii LIST OF ILLUSTRATIONS
FIGURE PAGE
26.
Boiling-point curve
of a
mixture
of two
liquids
66
27.
Macro apparatus
for
fractional distillation
68
28.
Hempel column
69
29.
Wurtz column

69
30.
Vigreux column
69
31.
Boiling-point curve
of a
solution
of two
liquids,
A and B,
which shows
a
minimum
71
32.
Boiling-point curve
of a
solution
of two
liquids,
C and D,
which shows
a
maximum
72
33.
Semimicro apparatus
for
fractional distillation

75
34.
(A)
Capillary
for
boiling-point determination (enlarged)
80
(B)
Boiling-point setup using capillary (A) . . . . 80
(C) Boiling-point setup using modified melting-point
capillary 80
(D) Capillary for boiling-point determination, according
to Emich 80
35.
Refractometer (Abbe) 83
36.
Refractometer (Fisher) 84
37.
Apparatus for the detection of carbon and hydrogen . 90
38.
Semimicro apparatus for Wurtz-Fittig reaction . . . 100
39.
Semimicro distillation apparatus for distilling directly
from an ordinary eight- or six-inch test tube . . . 101
40.
Macro apparatus for Wurtz-Fittig reaction 104
41.
Semimicro apparatus for separation of two immiscible
liquids 114
42.

Semimicro separatory tube in use 115
43.
Operation of semimicro separatory tube with one hand 116
44.
Semimicro apparatus for Grignard reaction 125
45.
Semimicro apparatus for bromination (may be used for
reactions where gases, soluble in water, are evolved) 141
46.
Macro apparatus for bromination or any reaction where
gases soluble in water are evolved 142
47.
Macro apparatus for preparation of ether 155
48.
Macro apparatus for steam distillation 166
49.
Semimicro apparatus for steam distillation, using six-
inch tube 168
50.
Semimicro apparatus for steam distillation, using eight-
inch tube 169
51.
Semimicro apparatus for oxidation of alcohols . . . 184
52.
Macro apparatus for preparation of Grignard reagent . 202
53.
Semimicro apparatus for preparation of acetyl chloride 213
54.
(a) Micro disperser for chlorine 225
(b) Semimicro apparatus for chlorination 226

55.
Macro apparatus for chlorination 228
56.
Macro apparatus for distillation under reduced pressure 233
57.
Apparatus for changing receiver during distillation under
reduced pressure 236
LIST OF ILLUSTRATIONS xiii
FIGURE PAGE
58.
Semimicro apparatus for distillation under reduced press-
ure,
using eight-inch tube 239
59.
Semimicro apparatus for distillation under reduced press-
ure,
using Claisen tube 240
60.
Polarizer P and analyzer A in parallel position . . . 244
61.
Polarizer P and analyzer A at right angles 244
62.
Polarimeter 245
63.
Semimicro constant-temperature bath 330
GENERAL INFORMATION
PURPOSE OF LABORATORY WORK
Organic chemistry is an experimental science; it was developed
by coordination of

reasoning
and experiment. The best way to ob-
tain an introduction to this field of knowledge is a well-directed
study involving a certain amount of laboratory practice. It is de-
sirable to acquaint the student at the very beginning with the
purpose of laboratory work. From the instructor's point of view
the chief aims of laboratory practice in the study of elementary'
organic chemistry are:
(1) To acquaint the student with the methods used for the
preparation of representative members of the most important
groups of organic compounds. The carbon compounds are arranged
into groups which show related properties. The preparation of one
or two members in each group serves to illustrate the principles of
the method which is applicable to an entire group of compounds.
(2) To provide a systematic study of the general properties and
reactions of the simpler groups of organic compounds. By means
of simple experiments it is possible to study some of the physical
and chemical properties of several compounds which belong in the
same group. In this manner the student obtains firsthand informa-
tion as to general group properties and reactions, and also as to
differences in reactivity among members of the same group.
(3) To develop the simpler skills and technics necessary in the
study of this particular field of experimental science. In order to
prepare and study organic compounds it is often necessary to per-
form distillations, crystallizations, extractions, determinations of
melting points, and other operations. Therefore, a number of these
operations are introduced at the beginning.
The aims listed above are not given in order of importance for
they are all equally important for the beginner. A number of other
aims can be listed. It is hoped, for example, that laboratory prac-

tice in any science will: (1) contribute to the teaching of the scien-
tific method; (2) aid in the development of critical thinking; (3)
enhance the student's enjoyment by enabling him to find out "how
1
2 GENERAL INFORMATION
things happen" and "how things behave." These are regarded as
by-products of any well-organized laboratory course in science.
Laboratory work exemplifies the general principle of learning
by doing. The attention of the student should be called to the fact
that one can be kept busy doing things for many years without
learning much. Acquisition of skills, technics and other mechanical
operations, although necessary for some scientific investigations
and very important to the beginner in the present study, are tools
in the study of science. The student may keep himself busy for two
or three hours in laboratory "goose-stepping" and following direc-
tions without learning much except a few isolated facts which,
before the year is over, are forgotten. In order that the student
may obtain as much benefit as possible from the laboratory work,
a method of procedure is outlined. It should be noted that this is
only one
method,
and for the same purpose the student may develop
his own. Any method is satisfactory provided the student knows,
while he is working, what he is doing and observing, and the explana-
tion for his observations.
GENERAL DIRECTIONS FOR LABORATORY WORK
Home preparation. It is advisable to study the assigned experi-
ment thoroughly before going to class. The student must not expect
to look at the directions one minute and work the next. It is there-
fore necessary to

have
a
definite
plan before going to the laboratory.
This is best accomplished by preparing an outline of what to do
and how to do it.
It is advisable to obtain specific directions from the instructor as
to the type (and method of recording) of the outline. The impor-
tant point is to have a definite plan. If the student can convince
the instructor that he knows how to work efficiently without an
outline, then the ritual of recording the outline can be omitted.
General precautions. Once in the laboratory, there are some
general rules to which every student must
conform
in order to avoid
accidents and insure the safety of his fellow students as well as
his own. Laboratory work in organic chemistry is connected with
some special hazards. Most organic compounds are highly inflam-
mable; in addition, some of the reagents, such as sodium metal,
bromine, concentrated acids and alkalies, and other reagents, are
a source of danger. Therefore a few general "Do's" and "Don'ts"
are given at this point:
(1) Read carefully the rules posted in the laboratory.
(2) Follow the directions which appear in each experiment.
GENERAL INFORMATION 3
Use the amounts of reagents specified. Be accurate, both in follow-
ing directions and in making observations.
(3) Follow the special directions and warnings given by the
instructor. If in doubt, ask the instructor or assistant.
(4) Do not point the open end of a test tube toward yourself or

another student. Tests which may give rise to violent reactions
should be performed in the hood with the mouth of the tube di-
rected toward the wall of the hood.
(5) Always wear
goggles
when performing distillations or mix-
ing reagents which may give rise to spattering.
(6) Work slowly and
carefully.
It is better to do a small amount
of work neatly and to understand it, than to do a large amount
hastily, carelessly, and to be vague about what you have done.
(7)
Cleanliness
is extremely important in all laboratory work.
Begin your work with clean apparatus and a clean bench, and end
your work in the same manner; the desk top and reagent bottles
should be cleaned and arranged before leaving the laboratory.
(8) Do not talk while you are working, but center all your at-
tention on what you are doing.
(9) The hands should be
washed
immediately after using poison-
ous substances such as potassium cyanide or sodium cyanide, ar-
senious oxide, phosphorus, etc. This precaution should be extended
to the majority of organic compounds.
(10)
Never heat inflammable solvents
in
open vessels.

(11) Do not heat closed systems. Inspect all vessels (flasks, dis-
tilling flasks, etc.) before starting to apply heat.
(12) Do not throw sodium residues into sinks or waste jars.
(13) Do not pour large volumes of inflammable or volatile sol-
vents down the sinks.
(14) Read the first-aid instructions which appear in the appendix;
refer to them in case of accidents.
(15) Record your observations promptly, in the manner de-
scribed in the following section.
THE NOTEBOOK
The recording of the observations is an important step in all
scientific work. The following method of recording experiments is
used in the author's laboratory; other instructors have methods
which better fit the particular conditions in their laboratories. The
important point, however, is that all methods are directed toward
training the student in the proper procedure of recording observa-
tions and conclusions as they are made, so that the notebook be-
4 GENERAL INFORMATION
comes the mirror of the work which was done. For this course, it
is reasonable to expect that a person informed in organic chemistry,
in examining a student's notebook, will obtain a clear picture of
what the student did, the observations he made, and the conclu-
sions which were drawn from these observations. The general di-
rections given below are to be modified in accordance with the
directions of the instructor in charge.
(1) The records of the student's work are made in a bound note-
book approximately 8 x 10 inches in size. This should always be
brought to the laboratory by the student, and must be ready for
inspection without notice. Loose-leaf books, individual sheets of
paper on which notes are kept and later copied, are not acceptable

to those working in the field of science.
(2) The first entries for an experiment represent the student's
preparation and are made before coming to the laboratory. The
descriptive paragraphs and directions of the manual should be
studied, with particular attention to the cautions for handling dan-
gerous materials. The lecture notes and textbook should be con-
sulted about the topic covered by the experiment. The following
information is then entered in the notebook:
(a) Date, title, and object of the experiment;
(6) Equation(s) involved in the preparation, or in the reac-
tions to be studied;
(c) If the experiment involves a preparation, other reactions
for making the same compound;
(d) The amounts (in grams and moles) of the reagents used,
and the theoretical yield;
(e) A table of the physical properties, such as melting or boil-
ing point, density, solubility, of each organic substance used or
formed in the reaction;
(/) A qualitative test to confirm nature of the compound;
(g) A diagram or flow sheet of the procedures and manipula-
tions;
(h) A list of the chemicals and apparatus needed, listing sep-
arately those which must be obtained from the stock room;
(i) The answers to the questions in the manual which are
marked with an asterisk. Those without an asterisk are to be an-
swered after the experiment has been performed.
(3) On arriving at the laboratory the student should obtain bis
instructor's approval of the outline which he has entered in his
notebook, and should then proceed with the work. During or im-
mediately after the experiment, entries are to be made in the note-

book giving a brief and concise account of the following:
GENERAL INFORMATION 5
(a) The operations performed and procedures followed;
(6) The observations made by the student, expressed in the
passive voice;
(c) The conclusions reached based upon the observations
made, and the explanation of the results obtained. If the equations
included in the homework preparation could not be completed,
they should be completed as soon as the experiment is performed.
A write-up of a typical experiment is given in the Appendix.
It is important for the student to learn a correct method of ex-
pressing his observations, conclusions, and ideas about his work.
Many students have a good understanding of a reaction but have
difficulty in expressing their ideas in an orderly and concise man-
ner. Therefore, the statements given by the student should be
grammatically as well as technically correct.
(4) Often in the laboratory a reaction is started but is not fin-
ished immediately, and another reaction is undertaken. In such
cases,
space should be left for the results to be inserted later. Some
instructors prefer, however, that students leave no empty spaces,
but record their observations as they are made; a line, and a small
caption, "Continued from page —," serve to provide continuity.
In this manner the laboratory notebook is a diary of the student's
experiences in the laboratory recorded as they occur. The instruc-
tor will indicate which method he prefers.
(5) Mistakes are made by all workers, including instructors. In
such cases they should be so marked in the notebook. Mark all un-
satisfactory data across with the word "canceled," or in any other
manner directed by the instructor. Figures should never be erased

nor pages torn out. All data, including those which are unsatisfac-
tory, are of importance. The errors represent definite
experiences
with one or more factors being responsible; the understanding of
these is of great importance to the student in his effort toward
self-improvement.
(6) Demonstration experiments should be written in the same
manner as those experiments performed by the student
himself,
with the notation that they are demonstrations.
(7) In many experiments it is possible to summarize a large
number of observations and other data by means of tables. In such
cases the tables appear in the questions and exercises at the end of
this manual. The pages of the manual on which the tables ap-
pear (as questions with space for one- or two-word answers) may
be detached after the material is filled in and pasted in the note-
book. If the student does not wish to detach these sheets, the
tables can be ruled in the notebook before coming to the labora-
6 GENERAL INFORMATION
tory. In either case the assigned brief essay-type questions should
be answered at the end of the write-up of the experiment.
(8) When the experiment is completed, the notebook should be
submitted to the instructor for approval before the next assignment
is begun. If the experiment is a preparation, the compound ob-
tained should be placed in a clean bottle or vial, labeled with the
name of the student, the name and physical constants of the com-
pound, the weight in grams, and the percentage of theoretical
yield. The preparation, together with a report made according to
directions given below, should be handed to the instructor at the
same time that the notebook is submitted for his approval. The

instructor probably will at this time discuss the student's work to
determine whether he has a clear understanding of his observa-
tions and conclusions. After this, the student may proceed with
the next experiment.
Reports and chemical accounting. A part of the student's train-
ing is to obtain experience in summarizing and reporting his ex-
perimental work. Therefore, for all experiments which involve
preparation of an organic compound, there is a standard form
1
which the student should fill in with all questions and problems
properly answered. There are four parts to each report. In the
first part the student reports the reaction used to prepare the
compound, the yield obtained, and the constants of the substance.
In the second part the equations of other reactions by which the
same compound could be prepared are given. In the third part the
student outlines a method by which the nature of the compound
prepared may be confirmed. In the last part of the report there is
a question on chemical
accounting
to be answered. It is common,
in organic preparations, for the yield to be very far from the
amount calculated on the basis of the chemical equation represent-
ing the reaction. Yields of only 40 to 50 per cent of the theory are
common in organic syntheses. It is reasonable to expect an ac-
counting in the products for every reagent that is put into a flask
or beaker. Although this is expecting a good deal from the begin-
ner, an attempt is made in the report sheets to encourage the stu-
dent to think about the other 50 or 60 per cent which was lost
mysteriously on the way. In some reactions it is possible to predict
most of the side reactions and to outline methods for the isolation

of the products formed. In others, one of the products may be a
tar of unknown composition, and the problem of accounting is
more difficult. Nevertheless, the student should attempt to find
1
Standard report sheets will be found at the end of the book.
GENERAL INFORMATION 7
some explanation as to the parts of the reactants that are not ac-
counted for in the yield. It is believed that the question of chem-
ical accounting, aside from the practical consideration, is impor-
tant because it reminds the student that the law of conservation
of mass applies as well when the yield is 20 per cent as when it is
90 per cent of the theory; further, it emphasizes the fact that most
organic reactions are multidirectional.
APPARATUS AND ITS CARE
APPARATUS FOR MACRO METHODS
Condenser. The condenser is one of the more common pieces of
glass .apparatus used in the organic laboratory. It is employed to
cool the vapors from evaporating liquids and condense them into
the liquid state. In Figure 1 are shown two condensers of Liebig
type.
They consist of an inner glass tube which fits inside the outer
jacket within which tap water is circulated. If the liquid boils
above 150° the water-cooled condenser is replaced by a long inner
tube called an air condenser. An ordinary condenser can be used
as air condenser, providing no water is passed through the jacket.
The condenser with the constricted-bulb inner tube is used at
times over a flask in which a liquid is being heated, in such a way
that the evaporated liquid continuously flows back again; this is
called heating under reflux. The length of the condenser jacket
varies from 300 to 700 mm, and of the inner tube from 500 to

950 mm. The type most commonly used for students has a jacket
length of 400 mm.
Distilling flasks. The common distilling flask has the side arm
placed usually 77 mm below the top of the neck so that the
thermometer can be immersed about 75 mm in the vapors of the
boiling liquids. The sizes vary from 25 ml to 3000 ml.
2
For beginners
the sizes of 50 ml, 125 ml, and 250 ml capacity are sufficient for
most purposes. The Claisen type, shown in Figure 1 has two necks,
one for filling or stirring, and the other as a vapor tube to which
the side arm is sealed. This flask is particularly useful in distilla-
tions in which considerable "bumping" and foaming occurs.
Flasks. Various types of flasks find use in the organic laboratory.
The student is already familiar with the boiling or Florence flask
and the Erlenmeyer flask. The sizes of the former most useful for
beginners are the 250 ml, 500 ml, and 1000 ml capacity; of the
Erlenmeyer flasks the 125 ml, 250 ml and 500 ml are the sizes most
s
The term "milliliter" (ml) is used throughout in the place of cubic
centimeter.
GENERAL INFORMATION
r
u
Condenser,
Liebig type
(modern style)
r
Condenser,
Liebig type (old

style)
Inner condenser
tube
Condenser
with COD-
stricted-bulb
inner tube
Distilling flask
Claisen-type distilling
flask
Boiling (Florence)
flask
Erlenmeyer flask
Round-bottom short-
neck flask
Fig. l(o)
Three-neck round-
bottom flask
GENERAL INFORMATION
Addition tube
Beaker
Bunsen funnel
(short stem)
Separatory funnel Separatory funnel Separatory funnel
(globe shaped) (Squibb) (cylindrical)
Buchner funnel
Filtering flask
Calcium chloride tube
Porcelain spatulas
Steel spatula

Fig. 1(6)
Adapter
10 GENERAL INFORMATION
commonly used. The round bottom flask with short ring neck, is
extensively used in advanced work, particularly in the preparation
of organic chemicals on a laboratory scale. The most useful sizes
are those of one and five liters capacity. The three-neck flask is
useful where a stirring device, reflux condenser, and addition of
reagents during the reaction are desired. An ordinary round bottom,
flask can be used for the same purpose by placing on top an addi-
tion tube.
Beakers. The beakers most useful for beginners are the 150 ml,
250 ml, 600 ml, and 800 ml or 1000 ml. Sizes of 2, 3, and 4 liters
are available for work involving the preparation of larger quan-
tities of organic compounds than usually are prepared by beginners.
Even for macro work it is desirable to have one or two 25 ml and
50 ml beakers for handling small quantities of materials.
Funnels. The student is familiar with the common (Bunsen)
funnel. The size most useful for the beginner has a diameter of
65 mm and a stem with a length of 65 mm. There are three general
shapes of separatory funnels as shown in Figure 1. For beginners
the globe-shaped type (125 or 250 ml) is most commonly used. A
long stem is desirable since it can be used both for the separation
of two immiscible layers and for the addition of reagents (dropping
funnel).
The Buchner
3
funnel has a perforated porcelain plate on which
to support the filter paper. It is used extensively in the organic
laboratory for the separation of crystals from a liquid. The sizes

available vary from 50-200 mm. The sizes most commonly used
are 90-100 mm. These funnels are used in conjunction with the
filtering flask. The funnel is fitted into the neck of the flask by
means of a rubber stopper, and suction is applied through the side
arm of the filtering flask.
Other macro apparatus. Either a porcelain or a stainless steel
spatula is very useful in the organic laboratory. A glass spatula
may also be made by heating a piece of glass rod and pressing it
to the desired shape.
The calcium chloride tube is filled with granular calcium chloride
and is attached through a stopper on a flask or bottle containing
liquids from which moisture is to be excluded.
The adapter tube is used to facilitate the delivery of the distillate
from the condenser to the receiver. It can be obtained either
straight, or bent at a 45° angle as shown in the diagram.
3
Also spelled Buchner and Buechner.
GENERAL INFORMATION 11
APPARATUS FOR SEMIMICRO METHODS
Simple apparatus can be constructed for work with small
amounts of materials in elementary organic experimentation. The
apparatus shown in Figures 2(d) and 2(6) is commercially available.
4
Test tubes. For most reactions tubes of 25 mm x 200 mm (eight-
inch tubes) are used. Three to four tubes of this size are ample for
a beginner. Standard Pyrex tubes of 20 x 150 mm (six-inch tubes)
are used in many of the semimicro technics; the number required
by a beginner is about ten to twelve tubes. A tube with a side arm,
25 x 200 mm, is useful as a filtering tube. The test-tube rack shown
in Figure 2 has places for four large tubes and six small tubes.

Semimicro distillation apparatus. The Pyrex micro distilling
flasks which are commercially available have a capacity of 10 ml
and 25 ml. It is advisable to modify the side arm of these flasks
as shown in Figure 2. The distilling tubes have been more success-
fully used in semimicro work than the ordinary distilling flask with
the straight arm because they are easier to clean, and because they
permit boiling with less danger of contaminating the distillate
by a spray from the bumping liquid. The distilling tubes are
made from ordinary six- and eight-inch Pyrex test tubes. A Claisen
type of distilling tube, useful in distillations under reduced press-
ure,
is made from an eight-inch Pyrex test tube.
Condenser. The semimicro condenser shown in Figure 2(6) is of
the so-called "cold finger" type. It consists of a glass tube about
150 mm long and 8—10 mm wide sealed at one end. Through the
opening is inserted an inner tube 160 mm in length and 4 mm wide.
The inner tube is held in position by means of a small piece of
rubber tubing. Two to three micro condensers are necessary for a
beginner. The rubber tubing for the circulation of water has about
a 5 mm inside diameter.
Heating baths. Beakers, of 125 ml and 250 ml capacity, may
serve as water-heating baths in semimicro work. Small tin cans of
two to three inches in diameter serve the same purpose without
any danger of breakage.
A three-purpose heating bath, specially developed for semimicro
work in organic chemistry, is shown in Figure 2(6). The bath is
made of metal and is 70 mm in depth and 90 mm in diameter. The
top is detachable but fits snugly so that no vapors can leak through
it. The top has four holes provided with short rings to support the
'Semimicro Apparatus for Organic Chemistry (Chicago: Wilkens-Anderson

Co.).