Hydration reactions are relevant for understanding many organic mechanisms. Since the experimental determination of hydration and hemiacetalization equilibrium constants is fairly complex, computational calculations now offer a useful alternative to experimental measurements. In this work, carbonyl hydration and hemiacetalization constants were calculated from the free energy differences betwee...

The first step in biological activity of cisplatin, one of the most efficient anticancer drugs, involves the hydration process. This chapter reviews the results of theoretical studies concerning the activation of cisplatin and its analogs. The complexity of the studied phenomena requires application of different theoretical tools. The energetic description of the extended hydration scheme was p...

the molecular geometry of complex of adenine with 8 water molecules was calculated with hartree-fock (hf). the standard 6-31g(d) basis set has been employed. the existence of c-h…o hydrogen bonds between the water molecules and the hydrophobic part of nucleobase is stablished. we optimized structures and computed interaction energies of all complexes of adenine with water molecules step by step...

A model that describes hydration and heat-mass transport in Portland cement mortar during steam curing was developed. The hydration reactions are described by a maturity function that uses the equivalent age concept, coupled to a heat and mass balance. The thermal conductivity and specific heat of mortar with water-to-cement mass ratio of 0.30 was measured during hydration, using the Transient ...

The physical status of water in seeds has a pivotal role in determining the physiological reactions that can take place in the dry state. Using water sorption isotherms from cotyledon and axis tissue of five leguminous seeds, the strength of water binding and the numbers of binding sites have been estimated using van't Hoff analyses and the D'Arcy/Watt equation. These parameters of water sorp...

This paper presents an agent-based modelling approach for hydration process of Portland cement taking place at the nanoscale. By following a combination of stochastic, deterministic and adaptive rules, cement system is allowed to evolve from an anhydrous separated state to a bond state with enhanced mechanical properties. We consider the two main chemical reactions producing C-HS gel and portla...

We report a new method to measure the kinetic rate constant of CO2 hydration using electrochemical oxidation carbon monoxide (CO oxidation) in isotope-labeled electrolyte. CO is often used as model reaction investigate surface metallic electrocatalysts, most notably stripping experiments. Using chip-based electrochemistry mass spectrometry with 18O-labeled electrolyte we show that: 1) For exper...

The enthalpies of the reactions in which methane hydrate is dissociated to methane vapor and either (1) water, or (2) ice are determined by a new analysis using the Clapeyron equation. The difference in enthalpies of the two reactions is used to infer the hydration number at the quadruple point where hydrate, ice, liquid water, and methane vapor coexist. By appropriate corrections, the hydratio...