Dissociation of hydrogen

The electronegativity system may be used. For example, in the chemisorption (with dissociation) of hydrogen on tungsten. 

The perhydroxyl ion, OOH , derived from the dissociation of hydrogen peroxide in alkaline solution, is generally considered the active agent in the bleaching of wood pulp using hydrogen peroxide. This ionization may be expressed by the following reversible reaction ... 

The enthalpy of dissociation of hydrogen bonds, A//nBomi, is a measure of their strength. Explain the trend seen in the data for the following pure substances, which were measured in the gas phase ... 

The mechanism is thought to involve dissociation of hydrogen, which reacts with molecularly adsorbed CO2 to form formate adsorbed on the surface. The adsorbed formate is then further hydrogenated into adsorbed di-oxo-methylene, methoxy, and finally methanol, which then desorbs. The reaction is carried out under conditions where the surface is predominately empty and the oxygen generated by the process is quickly removed as water. Only the forward rate is considered and the process is assumed to go through the following elementary steps ... 

In a number of cases, the temperature of the filament and thermodynamic parameters allow one to calculate [9] the flux intensity of free atoms produced in dissociation of molecules. Specifically, in the case of dissociation of hydrogen, oxygen, and nitrogen molecules on hot metal filaments under pressures of molecular gases higher than lO" Torr, the flux intensity of atoms A originating from A2 molecules is given by... 

CRITICAL POTENTIALS AND THE HEAT OF DISSOCIATION OF HYDROGEN AS DETERMINED FROM ITS ULTRA-VIOLET BAND SPECTRUM... 

Engels, H. et al., Direct dissociation of hydrogen iodide—an alternative to the General Atomic proposal, in Proc. 6th World Hydrogen Energy Conf., 2, 657-662, Vienna, Austria, July 1986. 

Figure 2.3 Left, reduction models. In the shrinking core or contracting sphere model the rate of reduction is initially fast and decreases progressively due to diffusion limitations. The nucleation model applies when the initial reaction of the oxide with molecular hydrogen is difficult. Once metal nuclei are available for the dissociation of hydrogen, reduction proceeds at a higher rate until the system comes into the shrinking core regime. Right the reduction rate depends on the concentration of unreduced sample (1-a) as f(a) see Expressions (2-5) and (2-6).

Chemisorption (i.e., absorption of hydrogen), which involves dissociation of hydrogen molecules into hydrogen atoms and chemical bonding of the atoms to a host matrix. Thus, the hydrogen is integrated in the lattice of a metal, an alloy or a chemical compound. 

To calculate the multicomponent vapor-liquid equilibrium, equilibrium constants for chemical reactions 1-9 are taken from literature in comparison to the original publication, in the present work different numerical values for the second dissociations of hydrogen sulfide and sulfur dioxide were chosen (cf. Appendix III). Henry s constants are evaluated from single solute solubility data without neglecting Poynting corrections ... 

The temperature dependency of equilibrium as well as of Henry s constants is given in tables A II.I and A II.II (cf. Appendix II). In comparison with the original publication for the equilibrium constants of the second dissociations of hydrogen sulfide and sulfur dioxide (reactions 6 and 7) numbers derived from Cobble (18) and Arkhipova et al. (J 9) were used. 

The hydrogen sulfide adsorption on the HKUST-l/GO composites was only studied in moist conditions [44]. The choice was based on the presence of water in the ambient air and on the extensive studies of H2S reactive adsorption on carbonaceous materials where water was important for dissociation of hydrogen sulfide before its further reaction with surface active sites [5]. Here up to 20 wt% of H2S was adsorbed in the composite with the smallest content of GO. [44]. An increase in the GO content resulted in a decrease in the capacity but nevertheless it was higher than that on MOF... 

The velocity will thus vary as the min power of the gas pressure. In the case of the dissociation of hydrogen molecules into atoms at the surface of a hot metal wire Langmuir found mln =, whilst for the recombination of atoms at a surface min was found to be 2. 

For reaction, e.g. the dissociation, of hydrogen at the surface of nickel, the fraction of molecules capable of so dissociating will be... 

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