Hydrochloric acid thermodynamic properties

Usually the acid-base properties of poly electrolyte are studied by potentiometric titrations. However it is well known, that understanding of polyelectrolyte properties in solution is based on the knowledge of the thermodynamic properties. Up to now, there is only a small number of microcalorimetry titrations of polyelectrolyte solutions published. Therefore we carried out potentiometric and microcalorimetric titrations of hydrochloric form of the linear and branched polyamines at 25°C and 65°C, to study the influence of the stmcture on the acid-base properties. 

Some of the compounds described in this chapter were studied for specific physical properties. Surface tension measurements with solutions of 9-16 in 0.01 M hydrochloric acid demonstrated that these zwitterionic X5Si-silicates are highly efficient surfactants.21 These compounds contain a polar (zwitterionic) hydrophilic moiety and a long lipophilic z-alkyl group. Increase of the n-alkyl chain length (9-15) was found to result in an increase of surface activity. The equilibrium surface tension vs concentration isotherms for 9 and 16 were analyzed quantitatively and the surface thermodynamics of these surfactants interpreted on the molecular level. Furthermore, preliminary studies demonstrated that aqueous solutions of 9-16 lead to a hydrophobizing of glass surfaces.21... 

Bates, R.G. and Bower, V.E., Standard potential of the silver silver-chloride electrode from 0-degrees C to 95-degrees C and the thermodynamic properties of dilute hydrochloric acid solutions, J. Res. Natl. Bur. Stand., 53, 283, 1954. 

Lustrous white, hard, ferromagnetic metal face-centered Cubic crystals, mp 1555". bp (calc) 2837" (3110 K) D. R. Stull. G. C. Sinke, Thermodynamic Properties of the Elements, Advances in Chemistry Series 18 (A.C.S.. Washington, 1956). d 8-90. Heat capacity (25 ) 6.23 cal/g -atom/°C. Mohs hardness 3-8. Latent heat of fusion 73 cal/g. Electrical resistivity (20 ) 6.844 uohms-cm. E taq) Ni/Ni2 0.250 V. Stable in air at ordinary temp burns in oxygen, forming NiO not affected by water decomposes steam at a red heat. Slowly attacked by dil hydrochloric or sulfuric acid readily attacked by nitric acid. Not attacked by fused alkali hydroxides. 

In a later paper Pollard et al discuss the use of the flame ionization detector in the gas chromatography of tetramethyltin, trimethylethyltin, dimethyldiethyltin, methyltriethyltin and tetra-ethyltin. They discuss the unusual sensitivity characteristic of the chromatography of these compounds and present and correlate specific dynamic properties obtained and various thermodynamic properties obtained on columns comprising 15% Silicone oil E301 (mol.wt, 700,000) on Celite (James and Martin ) (treated by dry sieving to mesh 36-60, washing with concentrated hydrochloric acid, methanol and distilled water, followed by drying at 300°C). 

Unlike the 4f elements, for which sesquioxides are ubiquitous, only the sesquioxides of Ac and Pu through Es have been prepared. Sesquioxides of Th through Np are clearly thermodynamically unstable with respect to disproportionation to the metals and the much more stable dioxides. (Those of heavier actinides would be obtainable if their half-lives were much longer and nuclear yields more favorable.) An overview of known actinide oxides, and their enthalpies of formation and standard entropies, was given earlier in Table 14.9 although most of the actinide sesquioxides have been known since before 1970 (Am203 since before 1950), only in the past decade have thermophysical [98] and thermochemical [99] properties been determined. Since the optimum solvent for solution calorimetry of these sesquioxides is moderately concentrated hydrochloric acid, a systematic approach to the prediction of the enthalpies of formation of other sesquioxides is to devise a cycle yielding the enthalpy of solution in infinitely dilute add ... 

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