Conductometric, spectrophotometric and thermodynamic studies of nickel sulfate in aqueous polyvinyl alcohol + methanol systems at different temperatures

Abstract

The electrical conductance of nickel sulfate (NiSO4.6H2O) solutions in aqueous, aqueous polyvinyl alcohol (PVOH; 0.1, 0.5 and 0.9 g/dL), aqueous methanol (CH3OH) system (30%, v:v) and aqueous PVOH+CH3OH systems were measured in the concentration ranges 0.4×10 -2 to 10×10 -2 mol/L, at different temperatures (298, 303, 308, 313 and 318 K). Ionic interactions of nickel sulfate in aqueous and mixed solvent systems were measured by conductometric analysis. Different relations were used to evaluate conductometric data, for the calculation of molar conductance, molar conductance at infinite dilution (Ʌ°m), degree of dissociation (), dissociation constant (Kd) and Walden product. The increased in Ʌ°m values with the increase in percent composition of aqueous PVOH, show that PVOH interaction with solvents (water and methanol) was higher as compare to PVOH interaction with NiSO4. Solvent effect was also studied by spectrophotometric analysis of NiSO4 in aqueous, aqueous PVOH and aqueous PVOH + CH3OH system. Thermodynamic parameters for dissociation process such as energy of activation (Ea # ), free energy change of activation (ΔGd # ), enthalpy change of activation (ΔHd # ), and entropy change of activation (ΔSd # ) were also calculated as a function of temperature and solvent composition.

Ionic-interaction of aqueous and alcoholic poly(vinyl alcohol) in the presence of protons

“…The Gibbs energy change of activation (∆G*) and the change in entropy of activation (∆S*) are expressed by the relations: [17][18][19] ∆G* = RTln (ηV m /hN A ) (7) ∆S* = (E a * -∆G*)/T The values of Gibbs energy change of activation tabulated in Table S-VI showed that an increase in the percent composition of PVOH resulted in higher values of the change in the Gibbs energy of activation. Whereas, increasing the concentration of acetic acid lowered the value of Gibbs energy change of activation.…”

Application Of Mohr’s Method For The Determination Of Chloride In Plant Tissue Extracts Using The Conductometric Titration

“…The conductometric analysis is one of the cheapest, reliable and valuable techniques used to confirm electrolytes nature, ion-solvent, ion-ion interaction in a solvent. It has also received significant attention in recent years due to its importance in various fields [22][23][24][25]. The aim and objectives of the current investigation were to apply Mohr's method using the AgNO 3 on plant leaves to provide an easy, cost-effective, simple analytical technique to detect chloride ions.…”