Enthalpies of Mixing for Binary Liquid Mixtures of Monocarbonic Acids and Alcohols

Similar documents
Hyperfine Structure in the Rotational Spectrum of Chloroacetonitrile

Dielectric Spectroscopy of Some Multihydroxy Compound Solutions in Water/Tetrahydrofuran Mixtures

Dielectric Study of the Ferroelectric Phase Transition in DMAGaS Crystal

Kinetic Study of the Acid Hydrolysis of Ethyl Hydrogen Succinate in Binary Solvent Mixtures

Application of the Pseudo-Spin Model to the Lowest-Temperature Phase Transition of the Mixed Crystal (NH 4 ) 2(1 _ x) K 2x Pb[Cu(N0 2 ) 6 ]

Ternary Intercalation Compound of Graphite with Aluminum Fluoride and Fluorine

Dimerization of Carboxylic Acids in Solution up to High Pressures and Temperatures. 2. Benzoic Acid

Thermodynamic Properties of Alkali Nitrate Silver Nitrate Melts

Introduction. Experimental. The early measurements have been performed at 1.81 T by a multi nuclei frequency-swept CW-spectrometer

TT o. Infrared Microwave Double-Resonance Investigations on Trifluoromethyljodide (CF 3 I) a) Experimental. E. Ibisch and U. Andresen. I.

Two-Dimensional NQR Spectroscopy for the Characterization of Crystalline Powders

NQR and NMR Studies of Phase Transitions in R 2 P b [ C u ( N 0 2 ) 6 l (R = K, Rb, Tl, Cs, and NH 4 ) *

Internal Mobilities in Molten (Li, Pb(II))Cl as Remeasured by the Klemm Method

Stability of Two Superposed Viscoelastic (Walters B') Fluid-Particle Mixtures in Porous Medium

UV Absorption Spectra of Methyl, Cyclopropyl Ketones. Jabria A. Al-Khafaji and Muthana Shanshal

An Interferometer for Direct Recording of Refractive Index Distributions

Molar Volume of Molten Binary CaCl 2 -NaCl, LaCl 3 -NaCl, and LaCl 3 -CaCl2 and Ternary LaCl 3 -CaCl 2 -NaCl Systems

A Fundamental Study on Uranium Isotope Separation Using U(IV) U(VI) Electron Exchange Reaction

To the Mathematical Concept of Thermostatics

Ground and Excited State Dipole Moments of LAURDAN Determined from Solvatochromic and Thermochromic Shifts of Absorption and Fluorescence Spectra

Control of a Chaotic Relay System Using the OGY Method*

Ag Nuclear Magnetic Resonance Studies of Organic and Inorganic Silver Complexes

Thermal Expansion of Alkali Sulphate Mixtures

Lattice Dynamics of Molybdenum and Chromium

Institut für Physikalische Chemie, Physikalische Chemie III, Technische Hochschule Darmstadt, Darmstadt, West Germany

Degree of Ionization of a Plasma in Equilibrium *

Chemically Induced Dynamic Nuclear Polarization*

Introduction. Experimental

The Oxidation of Formyl Radicals

Chemistry Department, Faculty of Science, Cairo, University, Egypt. Pyranoindoles, Pyridoindoles, Coupling, Benzylation

The Response of C 0 2 Evolution from Soils to Global Temperature Changes

Research on Nuclear Reactions in Exploding (Li + LiD) Wires

Determination of Superoxide Free Radical Ion and Hydrogen Peroxide as Products of Photosynthetic Oxygen Reduction

Proceedings of the XIII th International Symposium on NQR Spectroscopy

Description -of Cell Adhesion by the Langmuir Adsorption Isotherm

Vector Potential and Magnetic Field of Current-carrying Finite Elliptic Arc Segment in Analytical Form

Stoichiometry Effects on the Electrical Conductivity of Lithium-Manganese Spinels

Ultrasonic Studies of Ferroelectric Phase Transition in Gly-H 3 P0 3 Crystals

Static and Dynamic Dielectric Polarization and Viscosity of AZ-Hexylcyanobiphenyl in the Isotropic and Nematic Phases

Log-Compound-Poisson Distribution Model of Intermittency in Turbulence

Application of the Hard Sphere Theory to the Diffusion of Binary Liquid Alloy Systems

The G a m m a Radiolysis of Carbon M o n o x i d e in the Presence of Rare Gases*

1. Introduction. Reprint requests to Prof. F. Winterberg, Desert Research Institute, University of Nevada System, Reno, Nevada 89506, USA

Augmented Plane Wave Study of Electric Field Gradients in Non-cubic Metals*

Solvation of Coordinatively Saturated Metal Complexes of Nitrogen Ligands

NMR and NQR Studies of Borate Glasses*

Quiz I: Thermodynamics

Solution Structures of Pyrophthalones, I Structure and Conformation of l,3-indandionato-2(2-pyridinium)-betai'n a 1 H/ 13 C NMR Approach

The Hei and HeH Photoelectron Spectra of [Fe*?3-C3H5(CO)3X] and [Fe^3-C4H7 (CO) 3 X] ( X = Cl, Br, I) and [CoC3H5(CO)3]

1. Introduction. 2. Molecular Interactions and Spin-Lattice Relaxation

Binary Systems Containing Hydrocarbons

Synthesis of Pyridone Derivatives MICHAEL Condensation with Ethyl Cyanoacetate, Cyanoacetamide and Acetoacetamide

Introduction. Results

Membrane Fusion and Deformation of Red Blood Cells by Electric Fields

Calibration of a Slotted Disk Velocity Selector Using Supersonic Molecular Beams *

Chemical Energetics. First Law of thermodynamics: Energy can be neither created nor destroyed but It can be converted from one form to another.

Complicated Poincare Half-Maps in a Linear System

Cyanothioacetamide in Heterocyclic Synthesis: A New Approach for the Synthesis of 2-Pyridothione and 2-Pyridazinothione Derivatives

Molecular Orbital Theory of the Electronic Structure of Organic Compounds

Stereochemistry of Substituted Isomeric 3-Oxa-7-aza-bicyclo[3.3.1]nonan-9-ones

Akinori Shuto, Toru Takahashi. Yasushi Ohga, Tsutomu Asano, Hirokazu Saitoa, Kohei Matsuo a, and Hans-Dietrich Lüdemann b

Lattice Vibration Spectra. LX. Lattice Dynamical Calculations on Spinel Type MCr 2 S 4 (M = Mn, Fe, Cd)

Energy Gap and Line Shifts for H-Like Ions in Dense Plasmas

Chapter 11 part 2: Properties of Liquids

Properties of Gases and Gaseous Mixtures with a Morse Potential

Energetics. Topic

Chapter 11 part 2: Properties of Liquids

3.2 Calorimetry and Enthalpy

Structures of l-phenyl-3-methyl-pyrazolone-5 and its Benzoyl Derivatives +

X-Ray-Diffraction Study and Determination of Absolute Configuration of the Anticancer Drug S( ) Cyclophosphamide (Endoxan, Cytoxan, NSC-26271)

Photographical Record of the Dispersion Surface in Rotating Crystal Electron Diffraction Pattern

X-Ray Diffraction and Structural Properties of Aqueous Solutions of Divalent Metal-Chlorides

New Methods of Nuclear Quadrupole Resonance *

Overview. Types of Solutions. Intermolecular forces in solution. Concentration terms. Colligative properties. Osmotic Pressure 2 / 46

isomerization and inversion. Furthermore, due to their relation to crown ethers, o-phenylene chalcogenides deserve attention as potential complexing

Dielectric Relaxation Studies of Binary Mixtures of Ethanol and Chlorobenzene in Benzene Solution from Microwave Absorption Data

Ionic Motion of Phenethylammonium Ion in [C 6 H 5 CH 2 CH 2 NH 3 ] 2 PbX 4 (X = C1, Br, I) as Studied by l H NMR

On the Experimental Proofs of Relativistic Length Contraction and Time Dilation

Measuring and Expressing Enthalpy Changes. Copyright Pearson Prentice Hall. Measuring and Expressing Enthalpy Changes. Calorimetry

Versuchsanleitungen zum Praktikum Physikalische Chemie für Anfänger 1

A Fundamental Structure of Continuum Mechanics I. Elastic Systems

11B and 10B NMR Investigations in Aqueous Solutions

Thermodynamic Functions at Isobaric Process of van der Waals Gases

Interaction of Slow Neutrons with Cobalt and Tin

A Non-Steady-State Method of Measuring the Thermal Conductivity of Transparent Liquids

Molecular Orbital Calculations of Cu-Halides

The Quasistationary States in Multipulse NQR *

M easurem ent of the N a tu ra l L ifetim es and Q uenching R ate C onstants of O H (2l +, r = o,i) and O D (2r +, r = o,i) R adicals

Karlheinz D ietz, Heim o J. Keller*, Dietrich N öthe, and D ieter Wehe

The Development of Daffodil Chromoplasts in the Presence of Herbicides SAN 9789 and SAN 9785

A ttr a c to r M e rg in g C ris is in th e D o u b le -S c ro ll O s c illa to r*

Mass Spectrometry of Polymers: Polypropylene Glycol

Note: 1 calorie = 4.2 Joules

X-Ray Diffraction Study of the Electron Density and Anharmonicity in K 2 PtCl 6 *

Ch 9 Practice Problems

Dynamic Polarization, Molecular Motion and Solvent Effects in Several Organic Solutions as Studied by Proton-Electron Double Resonance

Thermochemistry. The study of the ENERGY CHANGES that accompany changes in matter. 3 Ways: Monday, February 3, 2014

Additional Calculations: 10. How many joules are required to change the temperature of 80.0 g of water from 23.3 C to 38.8 C?

Thermodynamics revisited

Chemistry Slide 1 of 33

Transcription:

Enthalpies of Mixing for Binary Liquid Mixtures of Monocarbonic Acids and Alcohols R. H a a s e and R. L o r e n z Institut für Physikalische Chemie, RheinischWestfälische Technische Hochschule, Aachen, Germany Z. Naturforsch. 40a, 947951 (1985); received July 3, 1985 We present the results of calorimetric measurements of the molar enthalpy of mixing (molar excess enthalpy) 77E as a function of temperature and composition (described by the mole fraction.y of the alcohol) for 18 binary liquid systems consisting of an aliphatic monocarbonic acid (formic, acetic, propionic, butyric, valeric acids) and an aliphatic alcohol (methanol, ethanol, 1propanol. 2propanol, 1butanol, 2methyl2propanol). The experiments cover temperatures between and and the whole range of compositions (usually nearly 40 compositions at each temperature). There is a great variety of behaviour as far as the function HE(x) for T = const is concerned. Many systems show endothermic mixing ( / / E > 0), other systems exothermic mixing (HE < 0), again other systems partly endothermic, partly exothermic behaviour. There is one case (acetic acid 2methyl2propanol) where HE(x) changes its sign twice and the molar excess heat capacity exhibits unusually large negative values. Previous calorimetric work in this l a b o r a t o r y concerns the enthalpies of m i x i n g (excess e n t h a l p i e s ) for the binary liquid systems water acetic acid [1,2], f o r m i c acid acetic acid [3,4] as well as f o r m i c acid propionic acid a n d acetic acid I propionic acid [4], We now t u r n to a c o m p r e h e n s i v e study [5] of 18 binary liquid systems a m o n g the 30 possible c o m b i n a t i o n s of the type acid alcohol formed f r o m the c o m p o n e n t s f o r m i c acid, acetic acid, p r o p i o n i c acid, butyric acid, valeric acid (aliphatic m o n o c a r b o n i c acids) a n d m e t h a n o l, ethanol, 1propanol, 2propanol, 1butanol, 2methyl2propanol (aliphatic alcohols) at t e m p e r a t u r e s between and a n d over the whole range of compositions (usually nearly 40 c o m p o s i tions at each t e m p e r a t u r e ). T h e systems investigated are shown in Table 1. O u r calorimeter [5] is an i m p r o v e d construction.of a flowtype calorimeter described earlier [4], based on the principle of c o n t i n u o u s flow a n d of continuous c o m p e n s a t i o n of t e m p e r a t u r e changes by s i m u l t a n e o u s use of a n electric heater a n d a Peltiereffect device. The q u a n t i t y derived f r o m the m e a s u r e m e n t s is the molar enthalpy of m i x i n g ( m o l a r excess enthalpy) HE as a function of the t e m p e r a t u r e T and Table 1. s investigated with respect to molar excess enthalpy HE as a function of the mole fraction.v of the alcohol at temperature T. The column "Type" indicates the type of the HE (.v)diagramm: the signs and refer to positive values of HE (endothermic mixing) and to negative values of HE (exothermic mixing), respectively. T Formic acid 1propanol 2propanol 1butanol 2methyl2propanol Acetic acid methanol ethanol 1propanol 2propanol 1butanol 2methyl2propanol 2methyl2propanol 2methyl2propanol Propionic acid methanol 2propanol 1butanol 2methyl2propanol Butyric acid methanol Valeric acid methanol 2propanol Reprint requests to Prof. Dr. R. Haase, Institut für Physikalische Chemie, RheinischWestfälische TH, Templergraben 59, 5100 Aachen t 1butanol 303.15 Type and and and 303.15 312.15 and 312.85 303.15 and and and I and and and 03404811 / 85 / 0900961 $ 01.30/0. Please order a reprint rather than making your own copy. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der MaxPlanckGesellschaft zur Förderung der Wissenschaften e.v. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namensnennung 4.0 Lizenz. This work has been digitalized and published in 2013 by Verlag Zeitschrift für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License.

948 R. Haase and R. Lorenz Binary Liquid Mixtures of Monocarbonic Acids and Alcohols Fig. 1. Molar excess enthalpy H E as function of the mole Fig. 2. Function H E (x) for carbonic acids lbutanol at fraction x of the alcohol for binary liquid mixtures of car. bonic acids and 2propanol at. Table 2. Parameters a k of (1) for the indicated systems (a: standard deviation). T a 0 a, a 2 a 3 a 4 a 5 a 6 Jmol 1 Jmol 1 Jmol 1 Jmol 1 Jmol 1 Jmol 1 J mol 1 J mol" Formic acid 1Propanol 1757.9 28.5 327.1 794.5 1833.8 675.0 1684.3 1.8 2Propanol 1905.4 84.3 1483.6 215.5 118.3 349.7 1.6 1Butanol 1187.9 337.5 454.5 592.3 1865.5 364.7 1634.5 2.7 2Methyl2propanol 303.15 3381.8 813.9 1853.4 599.8 1185.1 503.8 1378.2 4.3 Acetic acid Methanol 458.4 995.3 510.2 52.1 351.8 347.7 1.7 Methanol 385.3 956.1 634.0 110.4 100.1 91.9 2.2 Ethanol 599.4 865.5 451.5 166.4 202.0 2.8 1Propanol 1561.3 700.5 438.1 413.3 214.0 569.1 1.6 2Propanol 1761.4 472.3 638.9 1060.9 257.6 1010.8 2.8 2Propanol 1553.7 372.1 604.6 774.1 268.0 699.5 1.9 1Butanol 1956.7 797.4 523.2 535.0 223.1 648.1 3.1 1Butanol 1966.5 704.7 460.3 523.4 230.4 546.3 456.3 2.8 2Methyl2propanol 303.15 763.3 749.7 789.0 930.2 142.5 751.3 1.3 2Methyl2propanol 312.85 166.4 922.2 565.8 685.8 509.9 448.3 514.2 1.4 2Methyl2propanol 201.1 1007.8 672.2 523.7 113.3 88.1 1.7

R. Haase and R. Lorenz Binary Liquid Mixtures of Monocarbonic Acids and Alcohols 949 Table 2. (Continued) T «o «2 «3 a4 a 5 "6 er J mol 1 J mol" 1 J mol 1 JmoF 1 JmoF 1 J mol 1 J mol 1 J mol 1 Propionic acid Methanol 858.1 2068.5 719.2 470.8 777.4 258.3 480.4 2.2 Methanol 906.2 2047.3 614.6 315.9 1009.7 284.8 935.7 1.8 2Propanol 2557.0 1141.9 172.0 81.5 1731.4 67.0 1390.9 2.6 2Propanol 2484.6 1007.4 153.5 73.7 2823.3 144.1 2319.4 3.8 1Butanol 2417.4 1410.3 56.4 219.6 1981.3 476.0 1465.5 3.2 1Butanol 2513.4 1360.2 127.6 425.1 1206.8 684.9 610.4 3.0 lmethyl2pro 303.15 1668.5 1091.4 100.8 697.9 2094.3 444.4 1701.6 3.4 panol Butyric acid Methanol 1014.1 2091.3 793.0 65.2 87.9 247.3 2.7 Valeric acid Methanol 1534.5 1932.4 900.2 369.9 276.7 632.8 3.5 Methanol 1966.7 2036.4 716.5 137.7 151.6 66.8 2.9 2Propanol 2973.5 965.4 142.1 323.0 822.6 480.0 3.2 2Propanol 3073.4 854.0 235.1 781.2 383.7 846. 6.8 1Butanol* 2539.3 1407.2 408.5 581.4 2947.4 1742.8 3228.8 3.4 1Butanol 2809.5 1310.1 315.9 237.1 2201.1 83.1 1515.6 3.8 * Use parameters only for.v < 0,8! Fig. 3. Function H E (x). for acetic acid alcohols at Fig. 4. Function H E (.v) for carbonic acids methanol at.

950 R. Haase and R. Lorenz Binary Liquid Mixtures of Monocarbonic Acids and Alcohols Cp J mol" 1 " 1 10 15 0 0.2 OA 0.6 0.8 1.0 Fig. 6. Molar excess heat capacity Cf (x) for acetic acid 2methyl2propanol at 310.65 (derived graphically from H e, see Figure 5). of the mole fraction x of the alcohol, the pressure P being irrelevant. We fit the experimental data to the power series m H le = x (1 x) X a k (1 2 x)'* = x (1 x) *=0 (1) [fl 0 fli(l2jc)... fl m (l2.vh, where the parameters a k only depend on the temperature. We need up to 7 constants (a 0, a\,..., a 6 ) at each temperature to fit our results (see Table 2, where the standard deviation a is also given). In some cases we may derive the molar excess heat capacity (at constant pressure) m v (2) ' Cp = (S/7 e /6 T)p,, = x (1 X) X b k (1 2 x) k k = 0 with [see (1)] b k = da k /dt (3) from experimental values of the function H E (T, x). Figures 1 to 5 and 6 give examples of measured values of H E and Cf, respectively. In the last case (Cf for acetic acid 2methyl2propanol at 310.65 ) the data have been fitted to (2) using the parameters [without reference to (3)] b 0 = 64.4 J " 1 mol" 1, b,= 24.7 J" 1 mor', b 2 = 6.2 J"' mol 1, by = 13.3 J _ 1 mol" 1, the standard deviation being 0.2 J " 1 mol 1.

951 R. Haase and R. Lorenz Binary Liquid Mixtures of Monocarbonic Acids and Alcohols We now briefly discuss the functions H E (x) and Cp(.\) for given temperatures. In most cases (see Table 1 and Figs. 1 to 5) the process of mixing the liquid components is endothermic (H E > 0) throughout. However, systems containing formic acid show nearly throughout exothermic behaviour (/7 E < 0). In systems consisting of methanol and carbonic acids (the system formic acid I methanol being too exothermic to be susceptible to measurements) the function 77 E (x) is positive for small values of x (endothermic region), passes through zero, and is negative for large values of.v (exothermic region), the last region becoming smaller with higher carbonic acids and disappearing in mixtures with valeric acid. Finally, the system acetic acid 2methyl2propanol exhibits an extraordinary behaviour (see Figures 5 and 6): In a certain range of temperatures, the function H E (x) changes the sign twice, while the function C E (x) has unusually large negative values. [1] R. Haase, P. Steinmetz, and.h. Dücker, Z. Naturforsch. 27 a, 1527 (1972). [2] R. Haase and M. Pehlke, Z. Naturforsch. 32 a, 507 (1977). [3] R. Haase, H.J. Jansen,. Puder, and B. Winter, Z. Naturforsch. 34 a, 659 (1979). [4] R. Haase, H.J. Jansen, and B. Winter, Z. Naturforsch. 38 a, 1400 (1983). [5] R. Lorenz, Dissertation, RheinischWestfälische Technische Hochschule, Aachen 1985.

2024 © sciencedocbox.com Privacy Policy | Terms of Service | Feedback