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 Follow this and additional works at: https://scholars.fhsu.edu/theses Part of the Chemistry Commons 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 by 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.

Load more