Standard molar entropy

About: Standard molar entropy is a research topic. Over the lifetime, 1586 publications have been published within this topic receiving 29886 citations.

Thermodynamic Functions of Nano Zinc Oxide Acquired by Microcalorimetry and Electrochemical Methods

Abstract: Nano zinc oxide( Zn O) hierarchical structures with uniform size and morphology were prepared by microemulsion-mediated hydrothermal route. The thermodynamic functions at 298. 15 K,such as standard molar enthalpy,standard molar Gibbs free energy,and standard molar entropy of the synthesized nano Zn O were obtained by employing microcalorimetry and electrochemical method,individually. Microcalorimety for acquiring thermodynamic functions of nanomaterial was mainly based on that nano reaction system and its corresponding bulk reaction system possess the same transition state,whereas electrochemical method for acquiring thermodynamic functions of nanomaterial was mainly based on the difference of electrode potential between nanomaterial and its corresponding bulk material. The results reveal that the thermodynamic functions obtained by microcalorimetry and electrochemical method are approximately equal in the range of allowable error. The results also proved that both of the two developed methods to obtain thermodynamic functions of nanomaterials are effective and scientific. Moreover,it further support that the nano Zn O reaction system and its corresponding bulk Zn O reaction system experience the same transition state.

Adsorption Thermodynamics and Kinetics of Mancozeb onto Poly-o-toluidine Th(IV) Phosphate — a Nano-composite Cation-exchanger — and its Application as a Mancozeb-sensitive Membrane Electrode

Abstract: A newly-synthesized poly-o-toluidine Th(IV) phosphate nanocomposite cation-exchanger was employed as an adsorbent to study the adsorption thermodynamics and kinetics of Mancozeb from aqueous media. Some parameters such as the Freundlich constants, the thermodynamic equilibrium constant (K0), the standard free energy change (ΔG0), the standard enthalpy change (ΔH0) and the standard entropy change (ΔS0) were determined. Thermodynamic analysis revealed that the adsorption of Mancozeb onto poly-o-toluidine Th(IV) phosphate was exothermic, spontaneous and decreased as the temperature was increased from 25 °C to 45 °C. A pesticide-sensitive membrane electrode was fabricated using poly-o-toluidine Th(IV) phosphate as an electro-active composite material. Its sensitivity towards Mancozeb was monitored.