What You Always Wanted to Know about Heat Capacities, but Were Afraid to Ask

Ultrasonic Relaxation Study of 1-Alkyl-3-methylimidazolium-Based Room-Temperature Ionic Liquids: Probing the Role of Alkyl Chain Length in the Cation

“…[6][7][8] Unfortunately, this crucial condition can sometimes be overlooked. In other words, it should be keep in mind that for all aprotic RTILs studied to date, the determined f rel decrease with the decreasing temperature 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 30 and increasing side alkyl chain length in 3-methylimidazolium cation, 1 3,58 In other words, the lower the temperature, the higher the increase of the speed of sound with the decreasing temperature (concave up curve) is observed, and it is typical behavior in dispersion regions.…”

“…5 Ultrasound absorption investigations are also very useful and informative in the case of the pressure-temperature measurements of the speed of sound (an indirect route to obtain all of the observable thermodynamic properties of a fluid phase) as they must be carried out outside of the relaxation regions. [6][7][8] Furthermore, knowledge of ultrasound absorption is necessary in some methods used for the study of the nonlinear acoustic properties of the liquids. 9 Unfortunately, there is a lack of ultrasound absorption in ILs data available in the literature.…”

“…The densimeter was calibrated with water and dry air. The densities were measured over a range of temperature of 70 K or more (up to 363.15 K), and in each 7 case, the viscosity correction was made. For the kinematic viscosities, the measurements were done over a range of temperature of 40 K (from ca.…”

Microcalorimetry of Macromolecules: The Physical Basis of Biological Structures

“…Fundamental investigations on the Fig. 10 Thermodynamic representation of liquid hydrocarbon (benzene) dissolution into water assuming a constant heat capacity change [65] water solubility of hydrocarbons have provided essential information on hydrophobic effects, which are considered of pivotal importance in the formation and stability of higher order structures including proteins, nucleic acids, and cell membranes [61][62][63]. The transfer of nonpolar compounds into aqueous solution proceeds with a large negative entropy change, a finding that has been attributed to water ordering in the presence of nonpolar molecules.…”

CHAPTER 1. Volumetric Properties: Introduction, Concepts and Selected Applications

“…by directly measuring the volume increase on sudden decompression, this method is considerably less common and less accurate than that based on ultrasonics. 55,[78][79][80][81] For small sound wave amplitudes and sufficiently low frequencies well below any region where sound speed dispersion due to relaxation effects is observed, 82,83 to an excellent approximation v 2 0 ¼ @P @r…”