NOPR Collection:

Analysis of Volumes & Compressibilities of Aqueous Mixed Electrolytes with Three and Four Ions Using Virial Coefficient Theory

1989-01-01T00:00:00Z

Title: Analysis of Volumes & Compressibilities of Aqueous Mixed Electrolytes with Three and Four Ions Using Virial Coefficient Theory Authors: Kumar, Anil Abstract: The recently derived volumetric equations based on the virial coefficient theory of Pitzer are employed in estimating the densities and sound velocities of aqueous mixed electrolytes with three and four ion-systems up to the ionic strength of 3 mol kg^-1 of water. The predictive power of these equations is considerably improved if the interactions among like charge ions (repulsive forces) are explicitly considered along with the interactions among opposite charge ions. It is demonstrated that the excess properties of mixing at constant ionic strength can be satisfactorily presented within the framework of the Pitzer equations. A relationship is developed correlating the excess properties with binary interaction terms. Page(s): 1-5

Sorption of n-Butylamine on Ferric-Exchanged Y-Zeolites

1989-01-01T00:00:00Z

Title: Sorption of n-Butylamine on Ferric-Exchanged Y-Zeolites Authors: Kulkarni, S J; Kulkarni, S B Abstract: The sorption of n-butylamine (n-BA) on ferric exchanged Y zeolite catalysts has been studied. Freundlich equation is applicable to the sorption data of ferric-exchanged zeolites. The amount of n-BA retained on zeolites under vacuum at different temperatures has been reported which predicts the trend in the acidic strength. FeNaY (46) zeolite shows maximum number of strong acidic centres. The adsorption data for FeNaY zeolite, activated at 500°C, show migration of ferric ions from supercages to sodalite cages or hexagonal prisms, thereby lowering the acidity of zeolite. The isosteric heats of sorption of n-BA on FeNaY zeolites have been determined which support the heterogeneity of surface and migration of ferric ions after heating at 500°C. Page(s): 6-11

Linear Free Energy Relationships in Solid State Reactions: Part III-Reactions of Zinc Acetate with Aniline Salts

1989-01-01T00:00:00Z

Title: Linear Free Energy Relationships in Solid State Reactions: Part III-Reactions of Zinc Acetate with Aniline Salts Authors: Bassi, P S; Chopra, G S Abstract: Reactions between anhydrous zinc acetate and a series of substituted aniline hydrochlorides have been studied in the solid state. The products, characterized by elemental analyses and spectral data are ZnCl₂^. 2(XC₆H₄NH₂). The kinetics of these reactions have been studied by the mass loss method. Energy of activation values are 26.9, 38.9, 57.7, 144.7, 92.8, 117.4, 97.4, 162.2 and 186.5 kJ mol^-1 for X=2-Cl, 3-Cl, 4-Cl, 4-1, 3-OCH₃, 4-F, H, 4-CH₃, and 4-OCH₃, respectively. A plot of energy of activation with Hammett 0 constants of the substituents is linear. Unsubstituted aniline salt and 4-iodoaniline hydrochloride show deviations which have been interpreted in terms of differences in crystal structure and size of these reactants. The reactions proceed by the formation of an adduct, which then decomposes with the loss of gaseous acetic acid. Page(s): 12-15

Study of Phase Transformations in Copper Telluride

1989-01-01T00:00:00Z

Title: Study of Phase Transformations in Copper Telluride Authors: Sharma, Indu Bhushan; Batra, Sulekha Abstract: Differential scanning calorimetry and thermogravimetry show that Cu₄ Te₃, undergoes two phase transformations in the temperature regions 610-615 and 619-628 K with peak temperatures of 612.6 and 624.5 K respectively. The high temperature X-ray diffractometry substantiates the calorimetric results. The material is diamagnetic in the temperature range 323-643 K, which rules out presence of Cu²⁺ ions. Entropies of activation for the transitions have been computed. Page(s): 16-18