Some Physical Properties of the Ternary System; Cyclohexylamine - Cyclohexanol - Cyclohexane

Fort Hays State University FHSU Scholars Repository

Master's Theses Graduate School

Summer 1953

Some Physical Properties of The Ternary System; Cyclohexylamine - Cyclohexanol - Cyclohexane.

Arlin E. Mills Fort Hays Kansas State College

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Recommended Citation Mills, Arlin E., "Some Physical Properties of The Ternary System; Cyclohexylamine - Cyclohexanol - Cyclohexane." (1953). Master's Theses. 515. https://scholars.fhsu.edu/theses/515

This Thesis is brought to you for free and open access by the Graduate School at FHSU Scholars Repository. It has been accepted for inclusion in Master's Theses by an authorized administrator of FHSU Scholars Repository. SOME PHYSIC.AL PROPERTIES OF THE TERNARY SYSTEM: CYCLOHEXYLAMINE--CYCLOHEXANOL--CYCLOHEXANE

being

A thesis presented to the Graduate Faculty

of the Fort Hays Kansas State College in

partial fulfillment of the requirements for

the Degree of Master of Science

Arlin E. Mills, A. B.

Fort Hays Kansas State College

Date i

ACKNOWLEDGMENTS

The author wishes to acknowledge his indebtedness to Dr.

Harold S. Choguill, who suggested the problem and under whose direction this thesis was prepared, for his invaluable suggestions and constructive criticism. Acknowledgment is made to Dr. F. B.

Streeter for his advice in preparing the bibliography and thesis structure. Acknowledgment also is made to Mr. David T. Sorensen for helpful suggestions and to the Visual Education Department of

Fort Heys Kansas State College for their photographic assistance. ii TABLE OF CONTENTS

PAGE

INTRODUCTION • • • • • • • • • . • • . 1

The Theory of Liquids and Solutions 2

METHOD OF INVESTIGATION 8

EXPERIMENTAL • • • 10

Materials Used • • 10 Preparation of Samples . 12

Freezing Points •••• 20

Absolute Densities • 30

Refractive Indices 39 Solid Freezing Point Model ••• 47 INTERPRETATION OF DATA AND SUMMARY 49 BIBLIOGRAPHY • • • • • • • • • • • 51 iii

LIST OF TABLES

TABLE PAGE

I. Physical Constants of Materials Used •• 11

II. Composition of Binazy Solutions 14 III. Composition of Ternary Solutions ••• 16

IV. Calibration of Freezing Point Thermometer •• 21 v. Binary Freezing Points •• 23 VI. Ternary Freezing Points • 26

VII. Binary Densities •• 32 VIII. Ternary Densities 35 IX. Binary Refractive Indices 40 X. Ternary Refractive Indices • 43 iv

LIST OF FIGURES

FIGURE PAGE 1. Simple Freezing Point Depression. 5 2. Eutectic Freezing Point Depression 5 3. Simple Freezing Point Elevation ••• 5 4. Compound Freezing Point Depression ••• 5 s. Graphical Representation of Compositions of Solutions on a iernary Base ••••••••••••• 19 6. Calibration of Freezing Point Thermometer 21 Binary Freezing Point Curves •••••••••• 25 8. Ternary Freezing Point Curves 29 9. Binary Density Curves ••••• 34 10. Ternary Density Curves 38 11. Binary Refractive Index Curves 42 12. Ternary Refractive Index Curves 46 13. Solid Freezing Point Model ••• 48 1

IN'IRODUCTION

Cyclohe:xylamine, cyclohexanol, and cyclohexane are obtained from the catalytic hydrogenation of aniline, phenol, and benzene, respectively (1). Cyclohexane, cyclohexanol, and other alicyclic compounds also occur in petroleum, in the distillate from coal tar, and in the terpenes obtained from certain plants (2). Cyclohe:xylamine, some related compounds, and their derivatives have been found useful in industrial processes in the manufacture of insec- ticides, plasticizers, corrosion inhibitors, rubber chemicals and dye intermediates (3).

From the above information, it is apparent that these compounds are rather easily obtained and useful enough to merit an investigation to obtain more information about their nature.

The purpose of this investigation is to determine some of the physical constants of a ternary system that has cyclohe:xylamine, cyclohexanol, and cyclohexane as its components. The physical constants of the pure compounds are known but information is lacking on the behavior of binary and ternary mixtures of these compounds. A further purpose of this problem i s the construction of a solid freezing point model or diagram of tre ternary system: cyclohe:xylamine--cyclohexanol--cyclohexane. Data gained on this system would be useful and applicable to the fields of organic, analytical, and physical chemistry. 2

The Theory of Liquids and Solutions

A liquid may be regarded as a condensed gas or as a melted

solid (4). In this investigation it is more advantageous to con- sider a liquid as a melted solido

Crystals exhibit a definite pattern when X-rays are passed through them and at any instant liquids also possess something analogous

to a definite arrangement between neighboring molecules as shown by the

X-ray patterns that they exhibit (4). Moreover, expenditure of energy is required when one layer of liqµid is forced past another. These facts BI'l.d many more seem to be explained best on the hypothesis that the molecules are squeezed together by their own forces of mutual

attraction but that each molecule has a free volume surrounding it, in which it behaves effectively as an ideal gas . In a solid, the molecules cannot move from one place to another, but in a liquid they can, provided that a small amount of energy is supplied.

A solution may be defined as a system of different chemical

substances which has the same chemical composition and physical properties in every part (5). If the system is composed of only two chemical substances, it is called a binary solution. If the

system is composed of three chemical substances it is called a

ternary solution.

In an ideal liquid solution there is no special force of

attraction between the components of the solution, and no change in internal energy is produced on mixing (6). In an ideal solution 3 of components A and B the behavior of each substance is unaffected by the presence of the other. The attraction between two neighboring molecules of A, A--A, is just the same after the molecules have been ~spersed through the solution, and the attraction between two neighboring molecules of B, B--B, is just the same as in pure B.

Under these conditions no change in the character of the liquids is produced on mixing, merely a dilution of one licpid by t he other.

There is no heat effect in this -cype of solution and the physical properties are strictly additive. The physical properties of this type of system, such as freezing points, refractive indices, and absolute densities could be calculated directly by averaging the properties of the components which make up the solution. These properties could also be said to be linear functions of the composition.

In a nonideal solution there may be attraction A--B between neighboring molecules A and B which is greater than the A--A attraction or the B--B attraction. This ma;y result in changes of the physical properties of the solution. The freezing points and other properties would probably not be linear functions of tte composition and therefore, could not be calculated or predicted as in the case of the ideal solution. Many binary solutions of the nonideal type often exhibit freezing ppints with maxima or minima. In the case of the minima, for example, the solution would have a freezing point lower than either of its pure components. 4 The following figures show several different types of composition--freezing point curves that are exhibited by binary solutions (9). These curves are the main types f ound -when the components are completely miscible in the liquid state, which is true of the compounds used in this problem. 5

C C -0 -0 a. a. Cl Cl C C N N Q) Q) Q) Q) '- '- LL LL

100% A Composition I 00% B 100% A Composition 100%B

Figure I Figure 2

C -C - 0 0 a. a. Cl Cl C C N N Q) Q) Q) Q) '- '- LL LL

100% A Composition I 00 %B 100% A Composition 100%B Figure 3 Figure 4 6

Figure 1 shows a simple freezing point depression whereas,

Figure 2 shows a eutectic freezing point depression. In other words, two different types of single freezing point minima are shoWR. Curve

I 0f Figure 3 shows a simple freezing point elevation which exhibits a maxim.urn while Curve II of Figure 3 shows a case where the freezing points of all the mixtures lie between the freezing points of the pure compounds. When two components form a stable compound possess- ing a congruent melting point, then a freezing point curve similar to Curve I of Figure 4 is obtained. If however, a compound is formed which is unstable and decomposes before tre temperature reaches its true melting point, then it is said to have an incongruent melting point. This type is shown by Curve II of Figure 4. These changes in the freezi ng points and other physical properties from that of ideal solution may be attributed to s·everal different causes (6), (24). There are electrostatic forces between ions, dipoles, and induced dipoles in which case the solute is lmown to form dimers and trimers. The number of effective molecules in the system will be reduced accordingly, and the observed freezing point will be less than that predicted for the ideal case.

Another very common form of deviationr occurs when the solvent and solute, A and B, combine partially in the liquid phase to form a third substance, il. The deviation from ideality here is due to molecular compound formation as shown above. The formation of AB does not decrease the number 0f solute molecules in the solvent but 7 actually decreases the number of molecules of free solvent remaining~

The mole fraction of the solvent, therefore, is smaller, and the mole fraction of the solute greater than expected, so that the freezing point is greater than would be predicted from the ideal case.

In some cases, the solute molecules dissociate to form two or more molecules, thus increasing the effective mole fraction of the solute and giving rise to freezing point depressions greater than those calculated from the ideal case.

Another type of molecular interaction leading to nonideal solutions is that in which a hydrogen bond is formed making the

A--B attraction greater than t he A--A or the B--B attraction.

The same types of molecular interactions also produce devia- tions from ideality in ternary solutions (10). This is proved by the occurrence of ternary eutectic points, ternary compound formation, and other types of similar behavior. 8 METHOD OF INVESTIGATION

Since the freezing point of a soluti0n is a function of its composition, it is necessary that an ample number of solutions be studied to determine the type of freezing point curve that may be obtained. In this manner eutectic points could be located, md if chemical combination takes place, the nature of the compounds formed and the range of their existence could be ascertained. The freezing point of any composition may be obtained from a smooth curve plotted from the experimental data.

According to too thermodynamic definition, freezing point and melting point, terms frequently used interchangeably, designate the same temperature (25). This is actually a temperature at which solid crystals of the substance are in a:iuilibrium with the liq.iid phase. If this equilibrium condition is approached by cooling the liquid, the temperature is commonly called the freezing point, and if by heating the solid, it is called the melting point. Therefore, in this work the term freezing point has been used because too solutions had to be cooled to cause crystals to be deposited.

Since a number of samples are prepared to stuey a ternary system, it is advisable to determine some other physical constants of the solutions which can be used for identification purposes.

Since it is desirable that these constants can be quickly and accurately determined, the index of refraction and the absolute density have been chosen for this problem. 9 The interpretation of ·the accumulated data necessitates the plotting of a sufficient number of curves to show the relationship between physical constants and compositions. 10

EXPERIMENTAL

Materials Used

The cyclohe:xylamine, cyclohexanol, and cyclohexane used were of the purest grade commercial ly available from The Matheson Company,

Inc. They were further purified by redistilling in an all glass apparatus. The physical constants of the pure compounds are shown in the follewing table. 11

TABLE I PHYSICAL CONST.ANTS OF MATERIALS USED

Constant Literature Experimental

Cyclohe:xylamine

1.4565 (3) l.4570il-

o.8647 (3) 0.8592• H'<"

-17.7 (3) -17.7

Cyclohexanol

1.4606 (12) 1.4645* 0.9620 (13) o. 9414">.Y<- 23.9 (13) 23. 9

Cyclohexane

1.Lt273 (14) o. 7790 (13) 0.7692-ll--ll- 6.5 (13) 6.5 nB5 indicates refractive index for the D line of sodium at 25° Co d~§ indicates absolute density at 25° C. ~! indicates refractive index for the D line of sodium at 37° c. d~O indicates absolute density at 20° c. ~O indicates refractive index for the D line of sodium at 20° c. FP (° C) indicatesfreezing point in centigrade degrees. * refractive index determined at 27° c. absolute density determined at 30° C. 12

Preparation of Samples

In order that information obtained on the system might be represented graphically by means of valid smooth curves, it was deemed necessaxy to make up solutions varying in composition by

10 mole per cent. In this manner depressions and elevations of the freezing points in a series of solutions could be detected.

Also, there would be the advantage of knowing the relative numbers of molecules of each substance entering into the type of physical behavior obtained.

The mole fraction N of a substance in a solution is defined as the number of moles of that substance divided by the total number of moles of all the substances comprising the solution (7). If a binary solution contains nA moles of the substance A and~ moles of the substance B, then, the mole fractions of each component may be given by the following equations:

Mole fraction of A= NA~

Mole fraction of B =NB=

Calculation of the mole fraction of component A in a ternary solution where substances A, B, and C are present may be shown by the fallowing equation:: 13 nA Mole fraction of A= NA=------+ nB +- nC

A sample calculation to find the number of grams of each

component required to make up a binary solution ma,y be shown as

follows:

Composition (mole per cent) I Solution Number Cyclohexane Cyclohexanol Mol. Wt. 84.16 Mol. Wt. 100.16

29 20% 80%

2 X 84.16 X 100 . = 8.68 g. cyclohexane 2 X 84.16+ 8 X 100.16 X 2

8 X 100.16 X 100 = 4lo32 g. cyclohexanol 2 X 54.16 + 6 X 100.16 X 2

Multiplication of the nUJT1erators in tbe calculations by 100

converts the mole fractions to mole per cents on the basis of a

100 gram sample. Division by 2 limits the total weight of the

solution to 50 grams.

ill calculations were made using four-place logarithms and

the final answers were rounded to the nearest hundredth of a gram

since greater accuracy could not be justified from the data secured

in the freezing point determinations.

A total of 66 solutions were prepared (including the three

pure compounds). The samples were placed in three-ounce bottles with screw caps. Weighings were made on an 0haus trip balance with

a sensitivity of 0.05 gram. 14

TABLE II COMPOSITION ·oF BINARY SOLUTIONS

Cycl~hexylamine- -CycloheXB.nol

Solution Mole% Mole % Number Cyclohe:xylamine Cyclohexanol

1 100 0 2 90 10 3 Bo 20 4 70 30 5 60 40 6 50 50

7 40 60 8 30 70 9 20 80 10 10 90 11 0 100

Cyclohexane--Cyclohexylarnine

Solution Mole % Mole % Number Cyclohexane Cyclohexylamine

12 100 0 ]3 90 10 14 Bo 20 15 70 30 16 60 40 17 50 50 18 liO 60 19 30 70 20 20 80 21 10 90 1 0 100 15 TABLE II (Continued) COMPOSITION OF BINARY SOLUTIONS

Cyclohexane-- Cyclohexanol

Solution Mole% Mole% Number Cyclohexane Cyclohexanol

12 100 0 22 90 10 23 80 20 24 70 30 25 60 40 26 50 50 27 40 60 28 30 70 29 20 80 3(:) 10 90 11 0 100 16 T.ABLE III COMPOSITION OF TERN.ARY SOLUTIONS

10 Mole% Cyclohexylamine Series

Solution Mole% Mole% Number Cyclohexane Cyclohexanol

31 80 10 32 70 20 33 60 30 34 50 40 35 40 50 36 30 60 37 20 70 38 10 Bo

20 Mole % Cyclohexylamine Series

Solution Mole % Mole % Number Cyclohexane Cyclohexanol

39 70 10 40 60 20 hl 50 30 42 40 40 43 30 50 44 20 60 45 10 70 17 TABLE III (Continued) COMPOSITION OF TERNARY SOLUTIONS

30 Mole% Cyclohe:xylamine Series

Solution Mole % Mole % Number Cyclohexane Cyclohexanol

46 60 10 47 So: 20 48 40 30 49 30 40 So 20 50 51 10 60

40 Mole % Cyclohe:xylamine Series

Solution Mole % Mole% Number Cyclohexane Cyclohexanol

52 50 10 53 40 20 54 30 30 55 20 40 56 10 50

SO Mole% Cyclohe:xylamine Series

Solution Mole % Mole % Number Cyclohexane Cyclohexanol

57 40 lO 58 30 20 59 20 30 60 10 40 18

T.ABLE III (Continued) COMPOSITIONS OF TERN.ARY SOLUTIONS

60 Mole %Cyclohe:xylamine Series

Solution Mole% Mole % Number Cyclohexane Cyclohexanol

61 30 10 62 20 20 63 10 30

70 Mole %Cyclohe:xylamine Series

Solution Mole% Mole % Number Cyclohexane Cyclohexanol

64 20 10 65 10 20

80 Mole% Cyclohe:xylamine Series

Solution Mole% Mole % Number Cyclohexane Cyclohexanol

66 10 10 19

Figure 5 . Graphical Representation of Compositions of Solutions on a Ternary Base 20

Freezing Points

The freezing points of all the solutions were determined by using a simple form of the Beclanann freezing point apparatus (22) and

a low range, toluene-filled thermometer. Crushed solid carbon dioxide

and acetone served as the coolant bath.

The thermometer was calibrated by determining the apparent

freezing points of some pure substances. No stem correction was necessary as the thermometer was used in the same position at all

times in both calibration and determinations.

The tert-butyl alcohol, carbon tetrachloride, cyclohexanone,

and chloroform used were from chemically pure laboratory stock. The water used was from a freshly distilled laboratory s~pply of distilled water.

TABLE IV

CALIBRATION OF FREEZING POINT THERMOMETER

Thermometer Freezing Point Substance Reading Literature Correction tert-Butyl Alcoho1 2505° C 25.5° C (15) 0.0° C Water 1.0 o.o (16) -1.0 Carbon Tetrachloride -21.4 -23.0 (17) -1.6 Cyclohexanone -43.0 -45.o (19) --2~0 Chlorofurm -61.5 -6J.5 (17) -2.0 -3 -2 -1 0 I 2 u 3 L 25 20 15 10 5 0 - 5 -10 -15 -20 C -~ .,C, ... 0 u -3 -2 -1 0 I 2 3 -20 -25 -30 -35 -40 -45 -50 -55 -60 -65

Thermome t er Reading (°C .) I'\) I-' Figure 6. Calibration of Freezing Po int Thermometer 22

The freezing point of a solution is defined as the temperature at which the solution is in ecpilibrium with the pure crystalline solvent (21). Solutions when cooled, usually deposit one co mponent as a solid 0efore the other. The freezing point of a solution is not the temperature at which the solution as a whole becomes solid but the temperature at which it begins to deposit solid solvent if cooled slowly enough that equilibrium is maintained. Since supercooling is usually present in aey freezing point determination, t he liquid is stirred vigorously. As soon as crystals start to form the tube is removed from the bath, and vigorous stirring is continued while the temper ature on the thermometer is being read (22). The freezing point is the temperature reached after the initial supercooling effect has disappeared and the temperature remains constant for several seconds. Thus, it is also the temperature that lies between the temperature at which crystals begin to form and the temperature at which a few crystals remain in the solution on prolonged stirring (26).

A minimum of three readings was taken on each solution. The values shown in the following tables are the arithmetic means of the determinations. 23 TABLE V BINARY FREEZING POINTS

Cyclohezylamine--Cyclohexanol

Solution Mole % Mole % Freezing Nwnber Cyclohezylamine Cyclohexanol Point (° C)

1 100 0 -17 . 7 2 90 10 -19.5 3 80 20 -21.2 4 70 30 -11.7 5 60 40 - 6,.7 6 50 50 - 5.o 7 40 60 - 7.5 s 30 70 -14.7 9 20 80 - 7.8 10 10 90 7.9 11 0 100 23 . 9

Cyclohexane--Cyclohe:xylamine

Solution Mole% Mole% Freezin Nwnber Cyclohexane Cyclohezylamine Point ( 5 C)

12 100 0 6.5 13 90 10 - 5.o 14 80 20 -16.5 15 70 30 -28 .0 16 60 40 -33.2 17 50 50 -31.3 18 40 60 -29.1 19 30 70 -26.8 20 20 80 -24.4 21 10 90 -21.5 1 0 100 -17 .7 24 TABLE V (Continued) BIN.ARY FREEZING POINTS

Cyclohexane--C,Jclohexanol

Solution Mole % Mole% Freezin N1llllber Cyclohexane Cyclohexanol Point ( 8 C)

12 100 0 6.5 22' 90 10 6. 6 23 80 20 7.0 24 70 30 7.7 25 60 40 8.6 26 so so 908 27 40 60 11.3 28 30 70 13.2 29 20 80 15o9 30 10 90 19o0 11 0 100 23.9 25

I . , I I I I 25 I I I I I I - I 20 I/ I - ,. J - I , ... I I -

15 L.., 711;1 - .• ,n I ,.,,...,,~ ,,,. IT I i., • er .. I ...... -~ I 10 ·., ,.... -· , .... ,, ... I I ---~..... , .. II ... \ ,., &lo ' 1;, 1, ;, - .,- 5 .. : I' ' ' \ C J I 0 ' \ I , ' . I' 0 \ ,. !., J, ) -5 I I' j C \ ('(' - • I - I ,. 0 I u .... a.. I ,I ., .. \ / I Cl -10 " C I " (J N I cu I I cu ' ' \ ... I H LL -15 I I I 4:1 ( J c~ " I I ' I' , I "T1. , I -20 , .... \ .... , 1, {IJ .., . " ,, _ I I \ ..,, ... V ,_,. -25 I .·v· .1.J - ' \.. l ,,,.,..,., I \ ' ., (IV' - .n J ... ., ,,,. " " ,. ,>, -30 .._.., L.., - I IK I I \. ~, I ' -.. .,,.. 17 '' -35 IF.

-40 I I I I 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Mole Per Cent Components

Figure 7. Binary Freezing Point Curves

Numbers Refer to Solutions in Tobie V 26 TABLE VI

TERNARY FREEZING POINTS

10 Mole% Gyclohe:xylamine Series

r Solution Mole% Mole% Freezin Number Cyclohexane Cyclohexanol Point ( 5 C)

31 80 10 -4.7 32 70 20 -4.3 33 60 30 -4.1 34 50 40 -3.8 35 40 50 -3.3 36 30 60 -2.6 37 20 70 -1.0 38 10 Bo 1.5

20 Mole% Cyclohexylamine Series

Solution Mole% Mole % Freezin~ Number Cyclohexane Cyclohexanol Point ( C)

39 70 10 -16.4 40 60 20 -16.3 41 50 30 -16.2 42 40 40 -16.0 43 30 50 -15.5 44 20 60 -14.4 45 10 70 -12.3 27 TABLE VI (Continued) TERN.ARY FREEZING POINTS

30 Mole% Cyclohe:xylamine Series

Solution Mole% Mole % Freezin Number Cyclohexane Cyclohexanol _ Point ( 6 C)

46 60 10 -26.3 47 50 20 -24.2 48 40 30 -22.0 49 30 40 -19. 8 50 20 50 -17.7 51 10 60 -15.8

40 Mole% Cyclohe.xylamine Series

Solution Mole% Mole % Freezing Number Cyclohexane Cyclohexanol Point (° C)

52 50 10 -34.2 53 40 20 -27.4 54 30 30 -20.7 55 20 40 -15. 4 56 10 50 -11.0

50 Mole% Cyclohe:xylamine Series

Solution Mole % Mole% Freezin6 Number Cyclohexane Cyclohexanol Point ( C)

57 40 10 -32.5 58 30 20 -27.0 59 20 30 -18.3 60 10 40 -10.7 28 TABLE VI (Continued)

TERNARY FREEZING POINTS

60 Mole % Cyclohe:xylamine Series

Solution Mole% Mole% Freezing Nwnber Cyclohexane Cyclohexanol Point(° C)

61 30 10 -30).4 62 20 20 -25.8 63 10 30 -15.2

70 Mole %Cyclohexylamine Series

Solution Mole% Mole % Freezin§ Number Cyclohexane Cyclohexanol Point ( C)

64 20 10 -28.0 65 10 20 -23.7

80 Mole% Cyclohe:xylamine Series

Solution Mole % Mole % Freezing Number Cyclohexane Cyclohexanol Point(° C)

66 10 10 29

10 I 1 I I e-f f I 1- I 1 : H I '-+~1 l

0 -t 1-1-r-•-- i I-+-. + -r-- 1-t--t---t---J.&'-t-..,.+-+--++-+--++ --1-t-+--1rt-+--1-++---++---++---++---+1+--r+ -t i=+ L!, ,- ~ - -~ 1- -5 l"'f"T I I I I

- 10 c 0 n. - 15 c:,, _ ~" .o I - I I I I ~1 -~ I , _, , ~ N Q) Q) -20

-25

-30

-35

-4 0

Composition

F igure 8 . T ernary Freezing Point Curves Numbers Refer to Solutions in Tobie VI 30

Absolute Densities

A 25 rnL Pyrex pycnometer was used for all determinations of the absol~te densities. All weighings were made on a Christian

Becker Model .AB - 4 analytical balance.

The solutions, on which determinations were to be made, were placed in a Sargent constant temperature water bath set at 30° C.

The temperature of the bath was carefully adjusted at the beginning and it maintained this temperature within the limits of ± 0.02° C. without further readjustment. The bottles containing the solutions were placed in the bath at least an hour before the determinations were made . The pycnometer was rinsed twice with acetone after each determination and then dried in a stream of air.

For the calibration of the pycnometer and the determination of the absolute densities, the weight factor must be the subject of careful correction (18). The effect of buoyancy in air of the objects on the balance pans must be taken into account. The true weight of the pycnometer may be calculated from the following equation: Go = G [ 1L + (0. 0012/d) (0.0012/8.4)] where, Go = true weight of the pycnometer G = apparent weight of the pycnometer d = density of Pyrex glass (2 .25) 0. 0012 g. - weight of 1 cc. of air under ordinary conditions 31 and 8.4 = density of brass weights Hence, Go = 27.9322 [ 1 + (0.0012/2.25) (0.0012/8.4)] Go = 27.9322 [ 1.0004] Go = 27 .9434 g. Since the pycnometer filled with licpid was weighed in exactly the same manner as the pycnometer filled with distilled water and since the weight of the pycnometer had been corrected for the buoyancy of air, the following calculation mey serve as an example of the method used in figuring the absolute densities: Weight of pycnometer + water 54.4602 g. Weight of pycnometer (corrected) 27.9434 Weight of water 26.5168 g.

Weight of pycnometer + cyclohexane 4804290 g. Weight of pycnometer (corrected) 2709434 Weight of cyclohexane 20.4856 g. Assuming the absolute density of water is 0099567 g./ml. at 30° c. (20), then Weight of cyclohexane x Absolute density water at Weight of water t 0 c. = Absolute density cyclohexane at t 0 c.

"'"""~"'.,...... ,._20.4856 g X o • 9956~{ g. /ml • - o • ~692I g . /ml • 26.5166 g. All calculations of densities were made -with five-place logarithrns and the final answers were rounded to four decimal places. 32

TABLE VII BINARY DENSITIES ~

Cyclohe:xylamine--Cyclohexanol

Solution Mole% Mole% Absolute (d30) Number Cyclohexylamine Cyclohexanol Density 4

1 100 0 o.8S92 2 90 10 008692 3 80 20 o.8797 4 70 30 o.888S 5 60 40 0.8975 6 so so 0.9065 7 40 60 0.9150 8 30 70 0.9240 9 20 80 0.9308 10 10 90 0.9365 11 0 100 0.9414

Cyclohexane--Cyclohexyl amine

' Solution Mole% Mole% Absolute Cyclohexane Cyclohexylamine Density (d30) Number 4

12 100 0 0.7692 13 90 10 0.7771 14 80 20 0.7850 15 70 30 0.7946 16 60 40 0.8030 17 so so 008126 18 40 60 008217 19 30 70 0.8307 20 20 80 o.8401 21 10 90 o.8494 1 0 100 o.8S92 33 TABLE VII (Continued)

BINARY DENSITIES

Cyclohexane-- Cyclohexanol

Solution Mole% Mole % Absolute Number Cyclohexane Cyclohexanol Density dlo)

12 100 0 0. 7692 22 90 10 0.7854 23 80 20 0. 8026 24 70 30 0. 8200 25 60 40 0. 8375 26 So So o.8549 27 40 60 0. 8713 28 30 70 o. 8894 29 20 80 0.9068 30 10 90 0.9245 11 0 100 0.9414 34

0 .9500 I I I , __ ,_,__._.._;.I I _ TTi I - --- 1I ---hH--t-t-+--JIH--l-H--l--l---+-l-+-1--I-W--l--l-!-L1-l-+-f-l---+-+--+--+--1---J.-l- _.-l-..,--+_=a1.,""',,,a-- -t_;f~~;t!;;_t__:: +,-=-t~-=+;t~~;-t__:::;l·_t-J_---+;-J-_+!--l+-J-__:::1 ll--=-ri .\\t~~ti~~ic...-ih-_;_ _.+.J ~lif"\J~_J~-,~hl- -- t-t----j-t--t-t--H-l-+-t-l--tiH----f-H --++-++-l-l...t..C•~!\~• -1----.1,.-f"'!~'.'l=.,,..+-!11--~---1------1-1--J.4.--,~ u -i. ------+--,H--I-H--I-H--l-+-f-+-+---l--l--w'll~~-l!' ..:1--1----J.,,tf"""~-1--1!-+--1--l-l-.....l.a...JT--"Ulll"\ L..1-..L r\"' ~.,,.. II /

0 .9000 ov rt) -0 - >, - i.., - .. - u, - I/ .U ,.,.~ ,I,' I C \[ -- 0 .8500 I I ,... / ,,. ,.,,,. Cl) I I i,, " '- e" C. - 0 -j I -r-r,- -~--~ e, I Jf" >1, , _\ 1~ - - 1 Cl) I _.6 / I I 1"- ll ,,.. _,.. ::, _,__ __J ___.--t-._ . / _j_ I.. \,c: _ l-~ F-" + -t-.'"":,i-+-f-+-+-1--1- - 1 I I ;,_ a i/ I , er .,. - 0 I T r I l'l u, .,v· ;' - r:: ... J.,., .0 <( 0 .8000

------/2 ~ ~rT _I ~ -J r-1- -- -~ I I I _~ =:~I 1-•-..-+--..+----.--+-~1-+-+-----l--l-+---..-1--__,__,_=':::::~=:~=;~•= +2 I I - I j I I - _,__ ..;..I---'-l-+----'-f- l --+-1--l-+-1--1---1-----1 ------· 1 ·1- -, --,--r -+-1 ------r--~-r- ~- - 1-,...J,--1---1-..;.. 0 .750 0 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Mole Per Cent Components

Figure 9 . Binary Density Curves Numbers Refer to Solutions in Table VII 35

TABLE VIII TERNARY DENSITIES

10 Mole% Cyclohexylamine Series

Solution Mole% Mole % Absolute Number Cyclohexane Cyclohexanol Density ( d~O )

31 80 10 0.7960 32 70 20 0.8138 33 60 30 0.8318 34 50 40 o.8488 35 40 50 o.8665 36 30 60 o.8840 37 20 70 0.9021 38 10 80 0.9189

20 Mole% Cyclohexylarnine Series

Absolute Solution Mole% Mole% 0 Number Cyclohexane Cyclohexanol Density (dt )

39 70 10 0.8052 40 60 20 0 .. 8234 41 50 30 o.8407 42 40 40 0 .. 8591_ 43 30 50 0.8770 44 20 60 o.8945 45 10 70 0.9120 36 TABLE VIII (Continued)

TERNARY DENSITIES

30 Mole% Cyclohe:xylamine Series

Solution Mole% Mole % Absolute Number Cyclohexane Cyclohexanol Density (dl)0

46 60 10 0.8146 47 50 20 0.8331 48 40 30 o.8514 49 30 40 0.8696 50 20 50 o.8868 51 10 60 o.~050

40 Mole% Cyclohex;ylamine Series

Solution Mole% Mole % Absolute 0 Number Cyclohexane Cyclohexanol Density (d~)

52 50 10 0.8234 53 40 20 o.8421 54 30 30 0.8605 55 20 40 0.8789 56 10 50 0.8970

50 Mole% Cyclohexylamine Series

Solution Mole% Mole% Absolute 30 Cyclohexane Cyclohexanol Density (d ) Number 4

57 40 10 0.8319 58 30 20 o.8512 59 20 30 0.8699 60 10 40 0.8883 37 TABLE VIII (Continued)

TERN.ARY DENSITIES

60 Mole %Cyclohe.xylamine Series

Solution Mole% Mole% .Absolute Number Cyclohexane Cyclohexanol Density ( dt0)

61 30 10 o.8412 62 20 20 0.8601 63 10 30 o.8779

70 Mole % Cyclohe.xylamine Series

Solution Mole % Mole% Absolute 0 Number Cyclohexane Cyclohexanol Density ( d~ )

64 20 10 o. 8501 65 10 20 0 . 8100

80 Mole % Cyclohe.xylamine Series

Solution Mole % Mole% .Absolute 30 Number Cyclohexane Cyclohexanol Density (d4 )

66 10 10 o .. 8590 38

0 .9500

I I

I .J

0 .9000

I) ,, , !/ • 1.., J 1/i L, 1, - It' ' , I,' !/ / 1,1 _., 1 ?: t!Jttj=t!Jtt --LH--l-+l_,t"'--.r_t -+r-1+~t11..J"'--=\i l--1+_1-A'1--:.,,t 1---.,,,~-l-r-1+_t---1-+-... ,-1-1.,,.J4-" +-1:..+--i---J ·.;; .., i, V " I -- C 0 .8500 I .P .,,IA .,/ I _,.. ~· : !ii l:l Q) 1-1--,-+---1-H--+-·H i,,~,-L+/\ _ e-+1--1-i-- RV.,.+ -Hf---l-, 4-H++---1;,,"'' H r~'-'A~---1- t..?v-1--w-1----l----l!"L.1C,;lJl11 ---1----1-- 11 ---1----l-w-1--w~ 0 1 1 1 1 L1----1-11 1 ,!I" .,. -::a , , a , ,Vl.&,t--H -+-+-t-+-H!-i--+1 -+-H-++-f-+-+-H--I .! 1 I I I J. y w:n1 l/,.,•:..-,-,---,.---,1,

Composition

Fi9ure 10. Ternary Density Curves Numbers Refer to Solutions in Table VIII 39 REFRACTIVE INDICES

For the determination of the refractive indices, an excellent

Abbe refractometer manu:factured by the Bausch & Lomb Optical Company

was used. This instrument was used with white light (daylight) be-

cause it was manufactured to give values for t he yellow 11 D11 line of

sodium when used with white light (8). It was connected with rubber

tubing to a Sargent constant temperature bath set at 27° C. Water

circulated, by means of the tubing, through the refractometer and back to the constant temperature bath again. Much care was taken

at the beginning so that it was possible to keep the temperature

at 27° C with a variation not exceeding ± 0.02° C. No readjustment

for temperature control was necessary during the entire determin-

ation.

The refractometer was adjusted with d. -bromonaphthalene

provided with the instrument. Readings on distilled water and

several pure organic liquids were also taken as a further check

for accuracy. Clean, dry capillary tubes were used to place several drops

of solution on the prisms. To remove the solution, the prisms were

washed thoroughly several times with ethanol on absorbent cotton.

They were then wiped again with clean dry absorbent cotton to

remove the excess ethanol and allowed to dry before the addition

of the next sample. Three readings were taken on ea.ch sample and the values found in

the following tables are the arithmetic means of the readings. 40

TABLE IX

BIN.ARY REFRACTIVE INDICES

Cyclohexylamine-- Cyclohexanol

Solution Mole% Mole % Refracti~~ 1 Number Cyclohexylamine Cyclohexanol Index (nD )

1 100 0 1.4570 2 90 10 1.4.588 3 80 20 1.4608 4 70 30 1.4623 .5 60 40 1.l.i637 6 50 .so 1.Li646

7 40 60 1.4653 8 30 70 1.46.57 9 20 80 1.h658 10 10 90 1.46.53 11 0 100 1.4645

Cyclohexane--Cyclohexylamine

Solution Mole % Mole% Refractive Number Cyclohexane Cyclohe:xylamine Index (n~7)

12 100 0 1.L24o 13 90 10 1.426.5 14 80 20 1.L29.5 1.5 70 30 1.4330 16 60 40 1.436.5 17 .so 50 1.L399 18 40 60 1.4433 19 30 70 1.4467 20 20 80 1.4.501 21 10 90 1.453.5 1 0 100 104.570 41 TABLE IX (Continued) BINARY REFRACTIVE INDICES

Cyclohexane--Cyclohexanol

Solution Mole% Mole% Refractive Nwnber Cyclohexane Cyclohexanol Index (n27) D

12 100 0 l.42h.O 22 90 10 1.4277 23 Bo 20 1.4319 24 70 30 1.4360 25 60 40 1.4403 26 50 50 1.L.444

27 40 60 1.4489 28 30 70 l.L.530 29 20 80 1.4572 30 10 90 1.4611 11 0 100 1.4645 42

1.4700 I I I I I I +-Ff-I-, i 7•--+---i--+-+-!-l--l---1--'-'-_J_____j_J_ --l---t----+--1---1--i---+-I 1! ! I ,.,,,., 1 -- I '"··, ... - - ·• 11 1n r-, I.,,,< IT . 1 1.... II -1----t-t--t--t-+ti-t--+--~b.!-"'t~4- +--1---'1'-Fi-l-f-++-l----++-11-t--t-r-+--t-+-+--t-+-+-+-+-al'"-.,I I _Jo 1,/ ,. 1.4600 1,/ / • I I 1 1 -1->t-t-t-t--t-i--t-l-+-t-t-+--l-+-+-l--+-1-++-l-++-11-1--1-l----+--I- . ~"-1~c-+ -t-1-+-hiG~rl- -H-t--t-l-t--+-H---l-+-+-l--+-l-++-l-+___j-;l-----+--I-I-I---I-W-L~/ L/ ~ 1-+-+-+-+-..\-.11\7 '-l-'r 1'-f--- - I/ -~ j"I' ) I I I I I/ I"- ~-a NO I I I I/ - I I/ C 1.4500 I I I ...... I/ . '\ I V 1 ,c I .• ,, Q) - .., Jr "0 - - -= I Q) - I I ., > - ,

u 4 I !f' I I\.-~ -0 - 1.4400 I

Q) I :_l_j_ I/

0: I - I UT I :, -t--;--~--.-l-~ 77•~1/+=-• F--~~-~- l-+--1-++--11-+-1-l-++-l----+-,----,---l-+-I -'-1+W-l-- -1---1- 1 , I / i

I /'I I/ II• I I_.; ·c:i~ 1.4300 - I I I A L I ,-1--1-,-t-t-+-,-+-~1--,-+--tc-+-+-l-+-+- >----,---,,"'7--7--,·""j ~ i--+-+--l-+--'ll-+~1--·~ ,- -i-+-+--t--i-11 ~-1--+-1-+-+-!--+--+---4-

1.4200 100 90 80 70 60 50 40 30 20 10 0 0 10 20 30 40 50 60 70 80 90 100 Mole Per Cent Components

Figure II. Binary Refractive Index Curves Numbers Refer to Solutions in Table IX 43 TABLE X TERNARY REFRACTIVE INDICES

10 Mole% Cyclohe:xylamine Series

Solution Mole% Mole % Refractive Nwnber Cyclohexane Cyclohexanol Index (n~7)

31 Bo 10 1.4315 32 70 20 1.4364 33 60 30 1.4L10 34 50 40 1.4453 35 40 50 1.4498 36 30 60 lo454o 37 20 70 104586 38 10 80 1.4620

20 Mole% Cyclohe:xylamine Series

Solution Mole% Mole% Refracti~ Number Cyclobexane Cyclohexanol Index (1,) )

39 70 10 1.4358 40 60 20 1.4407 41 50 30 104450 42 40 40 1~4495

43 30 50 1.4539 44 20 60 1.4585 45 10 70 1.4624 44

TABLE X (Continued)

TERNARY REFRACTIVE INDICES

30 Mole% Cyclohe:xylamine Series

Solution Mole% Mole% Refracti~e Nwnber Cyclohexane Cyclohexanol Index (nD7)

46 60 10 1.4388 47 50 20 1.4437 48 40 30 1.4488 49 30 40 1.4535 50 20 50 1.4581 51 10 60 1.4620

40 Mole% Cyclohexylamine Series

Solution Mole % Mole% Refracti~~ Number Cyclohexane Cyclohexanol Index ( Ilj:i ' )

52 50 10 1.4425 53 40 20 1.4475 54 30 30 1.4523 55 20 40 1.4572 56 10 50 1.4614

50 Mole% Cyclohe:xylarnine Series

Solution Mole% Mole % Refracti~ Nwnber Cyelohexane Cyclohexanol Index (nD)7

57 40 10 1.4458 58 30 20 1.4510 59 20 39 1.4561 60 10 40 1.4.605 45 T.ABLE X (Continued) TERN.ARY REFRACTIVE INDICES

60 Mole % Cyclohexylamine Series

Sol ution Mole% Mole% Refractive Number Cyclohexane Cyclohexanol Index (n~7)

61 30 10 1.4488 62 20 20 1.4544 63 10 30 1.4.595

70 Mole % Cyclohe.xylamine Series

Solution Mole% Mole % Ref racti~~ Number Cyclohexane Cyclohexanol Index (nn')

64 20 10 1. 4526 6.5 10 20 1.4.575

80 Mole% Cyclohexylamine Series

Solution Mole% Mole % Refracti e Number Cyclohexane Cyclohexanol Index (nD7)2

66 10 10 1.4.557 46

1.4700 -+-+--1-1---+-l--l--+--1-1----1-1-i- I -+-f-+-+--l-+-+-l-+-+--l-f---H-f---1--+-+--H-+-H-l---!1 ,_ -H j T- I a ( A

l , , / 1.4600 / Ill. I, ,I< II' / ' I/ / I J

/ J IJ IJ I , 17 / / J ,, J / ' I J ,::: ++'-il; J/1--,,, l~·--...-, H ·-lv-A--+-H-+H -+-H-++-H--! C\10 1.4500 J / ..5 I ,. ( / fl) ~· I 7 / II' / -c, 1 1 I II' ·-:: -t-t,a:;;h...-. \--!--'-)/4--+I - l-+-;J-J/4--+--l-++-f-4-L i'---H++--l-l-+-l-++H+-l-l-++-l-++H -= 7 -Z l J 'It J Q) ,/ I I fi I I ( > 17 TA' T u 1.4400 -i-----4-_ -!---~- I .II l--l-----'-lJ 'l--1'-l--7 ---'.------..1.~1~·<_,--t..~ ''i'<+--l-+-+l+- l-l-+-+-l--+-+--+-1·-++-l-+---l-1--+-l-+-+-++--l-+--l-l--l----1-+-+-++--l--l fl) a: '-· I/ . - l--+-t-H--rl-'-,- 1--: . l.1.l:L I 1 -•~_J_l_l I , f;7=t=F·-;- 1-~c...;._;_:-,-- ~-1--H--+-+-1-i-f--1:- I'---+_;~__;-_+-l-----1__,_-_-1--'--+_-__;-_ +,_--1__,_-_-1--c..-+... -__;-_+-l----l__,_-_ -1--11-1 _, ; Lll I -,- i --- I I I I 7 i l--'----l-+-+---+-+JI --+-+-1-1-----1-+-+--+-I - _ __J_!_J___;__ -·... '-r I 1. 4300 - ... __!___!____! ·---- : I ,_...... _-l---->-+---'--I ' ----''---"-...... _I -l---->...._. ~_:=r-= ~·,+--J~T, ,---il : : I T I

I I I --r--- T TT ... ,--+------, I + ....L _J_J,_.;..,' -'-T'---'-T++-+-+--1-• I I I ·1 1.4200

Composition

Figure 12 . Ternary Refractive Index Curves Numbers Refer to Solutions In Table X 47 Solid Freezing Point Model

In order to correlate the information obtained on the ternary system more accurately, use was made of the solid prismatic model or diagram (11). In this manner the freezing points of the solutions in their respective positions in space can easily be seen and ternary eutectic points can also be easily detected.

The model was constructed so that its triangular base corresponds to a sheet of triangular graph paper, as shown in Figure 5. The composition of the solution determines its respective position on the base. The height of the model represents temperature which ranges from -40° C. to 23.9° c. and is constructed to a scale which allows three-sixteenths of an inch for one centigrade degree.

The upper c0rners of the model represent the freezing points of the pure components, cyclohe:xylamine, cyclohexanol, and cyclohexane. The upper edges of the sides of the model represent the three freezing point curves for the binary systems: cyclohexylamine-- cyclohexanol; cyclohexane--cyclohe:xylaiirl.ne; and cyclohexane--cyclohexanol. Areas bounded by a side of the triangular prism apply either to a pure component or to binary solutions, while areas situated entirely within the triangular prism apply to ternary solutions. 48

Figure 13. Solid Freezing Point Model 49 INTERPRETATION OF DATA AND SUMMARY

Freezing points, refractive indices, and absolute densities were determined on the ternary system·: cyclohe:xylamine--cyclohexanol

--cycl0hexane.

The freezing point curve of the cyclohe:xylamine--cyclohexanol system (Fig. 7) indicated that a compound with a congruent melting point was formed. The congruent melting point, -5.o 0 c., occurred at the. composition of 50 mole per cent cyclohexylamine and 50 mole per cent cyclohexanol. Confirmation of the compound was found in the literature which stated that cyclohexylamine and cyclohexanol react to form an addition compound that melts below room temper-

ature (27).

The equimolar solution was then reacted with phenyl isothiocyanate and a thiourea, m.p. 145-6° C., was obtained which corresponded to the eyclohe:xylamine derivative, m.p. 148° C.,

(23). This indicated that the amine-alcohol addition compound

dissociated when the derivative was made.

Both the binary refractive index curve (Fig. 11) and the binary density curve (Fig. 9) of this system exhibited a slight elevation at 50 mole per cent cyclohexylamine and 50 mole per cent cyclohexanol which supported the above evidence that an

addition compound formed between equimolecular anounts of cyclohe:xylamine and cyclohexanol.

The cyclohexane--cyclohe:xylamine binary system exhibited

a freezing point curve (Fig. 7) with a eutectic freezing point 50 depression. The eutectic point, -33.2° c., occurred at a composition of 60 mole per cent cyclohexane and 40 mole per cent cyclohe.xylamine.

A type of freezing point curve in which all of the freezing points of the rniA~ures lie between the freezing points of the pure

compounds was found for the cyclohexane--cyclohexanol system (Fig. 7) .

In both of the latter systems mentioned, the absolute density

curves (Fig. 9) and refractive index curves (Fig. 11) indicated that

these properties were additive since the curves ran in nearly straight

liRes between the values of the pure components.

In the ternary system, the freezing point curves (Fig. 8) of

the 10 and 20 mole per cent cyclohe.xylamine series were similar in

form to the cyclohexane--cyclohexanol freezing point curve. From the 30 mole per cent cyclohe.xylamine series through the 80 mole per

cent series, the freezing point curves all supported the fact that

an amine-tlcohol addition compound formed in the cyclohexylamine--

cyclohexanol binary system.

A ternary eutectic point, -34.2° c. was also found at a composition of 50 mole per cent cyclohexane, 40 mole per cent cyclohexylamine and 10 mole per cent cyclohexanol.

The ternary absolute density curves (Fig. 10) and refractive

index curves (Fig. 12') indicated that these properties were additive because the curve of ~a.ch series was very nearly a straight line. 51

BIBLIOGRAPHY

1. Brewster, Ray Q., Organic Chemistry. New York: Prentice- Hall, Inc., cl948. P. 757 .

A late textbook of organic chemistry.

2. Ibid., PP• 751-753.

3. Carswell, T. S., and H. L. Morrill, 11'Cyclohexylamine and Dicyclohe:xylamine--Properties and Uses, 11 Chemical Abstracts, 31:8521, November, 1937.

A source far the physical properties and uses of cyclohexylamine. 4. Daniels, Farrington, Outlines of Physical Chemistry. New York: John Wiley and Sons, Inc., 1948. P. 166.

A late textbook of physical chemistry.

5. Ibid., P• 194.

6. Ibid., PP• 197-199.

7. Ibid. , p. 195.

8. Daniels, Farrington, (and others), Experimental Physical Chemistry. New York: McGraw-Hill Book Company, Inc., 1941. P. 48.

A laboratory manual for physical chemistry.

9. Findlay, Alexander, The Phase Rule and Its Applications. New York: Longmans, Green and Co., Ltd., 1927. Pp. 102-126.

A textbook of physical chemistry on the phase rule and its applications.

10. Ibid., PP• 219-223.

11. Ibid., PP• 224-225. 12. Gilchrist, Raleigh, (and others), "Chemical Compounds, 11 International Critical Tables, Vol. I, Editor-in- Chief: Edward N. Washburn. New York: McGraw-Hill Book Company, 1926. P. 279.

Tables of numerical data of physics and chemistry; a source of physical constants of chemical compounds. .52

13. Ibid., P• 202.

14. Ibid., P • 276.

15. Ibid., P• 189. 16. Ibid., P• 106. Ibid., P• 176. 18. Jasper, Joseph J., Laboratory Methods of Physical Chemistry. New York: Houghton Mifflin Company-;- cl93B. Pp. 36-39.

A laboratory manual for physical chemistry.

19. Lange, Norbert Adolph, (and others] , Handbook of Chemistry. Sandusky, Ohio: Handbook Publishers, Inc.,1946. Pp. 416- 417.

An extensive handbook of physical constants of chemical compounds, and chemical and mathematical formulae .

20. Ibid., P• 1358. 21. Millard, E. B., Physical Chemistry for Colleges. New York: McGraw-Hill Book Company, Inc., 1946. P. 214.

A te}...-tbook of physi~al chemistry.

22 . Shriner, Ralph L., and Reynold C. Fuson, The Systematic Identification of Organic Compounds. New York: John Wiley and Sons, Inc., 194tl. Pp. 23-24. A recent laboratory manual for the qualitative analysis of the simpler organic compounds.

23. Ibid., P• 234 . 24 . Skau, E. L., and H. Wakeham, "Melting and Freezing Temper- atures, n Arnold Weiss berger, Editor, Technique of Organic Chemistry, Vol. I. Physical Methods, Part I .. Second Edition; New York: Interscience Publishers, 1949. Pp. 56-57. A late compilation of methods for determining physical properties of organic chemical compounds .

25 . Ibid., p., 50 . 53 260 Ibid., P• 90.

27. Winans, Charles F ., "Addition Compounds of Dicyclohe.xylamine, 11 Journal of the American Chemical Society, 61:3591-2, December-;-1939.

Description of amine-alcohol addition compounds.