Potential diagrams

Thermodynamic data (4) for selected manganese compounds is given ia Table 3 standard electrode potentials are given ia Table 4. A pH—potential diagram for aqueous manganese compounds at 25°C is shown ia Figure 1 (9). 

Figure 1.1 (a) Chemical potential diagrams for systems forming a complete... 

Figure 3.2 Chemical potential diagrams for the transport of silicon carbide by chlorine, showing that the much greater stability of SiCU than CCI4 makes this process very inefficient, while the use of HCl as the transporting gas can be operated under optimum conditions...

The chemical potential diagram for this ternaty system (Figure 3.3) shows that the reaction with the elements would reduce the iodine pressure to a very low value, which is not suitable for CVD, whereas tire compound Ta5Si3, in which the chemical potentials of the two elements are about 40kJgram-atom would be suitable for CVD at about 1300 K. 

Figure 3.3 Chemical potential diagram for the transport of titanium silicides by chlorine, showing that only TaSi2 can provide the proper ratio of Ta and Si for stoichiometric transport...

Because of possible errors in determining pitting potentials from I(t/) curves, it is safest to take them from pit density-potential diagrams which can be determined by chronopotentiostatic experiments. Figure 2-16 shows the results of experiments on 1.4031 CrNi stainless steel (AISI304) in neutral waters [52]. 

In contrast with the Pb-HjO system, it can be seen in Figure 4.13 that in the presence of SO " the corrosion zone in the region of low pH no longer exists, owing to the thermodynamic stability of PbSO. The Pb-HjO-COj system has been expressed in a similar pH/potential diagram in which account has been taken of insoluble carbonates and basic carbonates of lead. 

The predictions of the pH/potential diagram are generally fulfilled, but in very concentrated acid solutions, attack may diminish, owing to the relative insolubility of the relevant salt in the acid. Thus, lead nitrate, although soluble in water, has (owing to common ion effect) only slight solubility in concentrated nitric acid, and the corrosion rate is reduced. Similarly, lead chloride is less soluble in moderately concentrated hydrochloric acid than... 

The consideration of

potential diagrams, that of yjr to the free energy surface,... 

The PMC transient-potential diagrams and the equations derived for PMC transients clearly show that bending of an energy band significantly influences the charge carrier lifetime in semiconductor/electrolyte junctions and that an accurate interpretation of the kinetic meaning of such transients is only possible when the band bending is known and controlled. 

FIGURE 6.34 An electrostatic potential diagram of ethanol, C2H OH. An electronegative atom (here, the O atom) can pull electrons toward itself from more distant parts of the molecule, as shown by the red tint over the O atom. Hence it can influence the strengths of bonds even between atoms to which it is not directly attached. 

The (photo)electrochemical behavior of p-InSe single-crystal vdW surface was studied in 0.5 M H2SO4 and 1.0 M NaOH solutions, in relation to the effect of surface steps on the crystal [183]. The pH-potential diagram was constructed, in order to examine the thermodynamic stability of the InSe crystals (Fig. 5.12). The mechanism of photoelectrochemical hydrogen evolution in 0.5 M H2SO4 and the effect of Pt modification were discussed. A several hundred mV anodic shift of the photocurrent onset potential was observed by depositing Pt on the semiconductor electrode. 

Fig. 2. Potential diagram of the redox couples of chromium. According to Csanyi . References pp, 577-580...

Fig. 14. Schematic representation of a mixed potential diagram for a generic electroless deposition reaction. The dashed line represents the current for metal ion reduction in the presence of a stronger complexing agent.

Figure 14 shows a schematic representation of a mixed potential diagram for the electroless deposition reaction. Oxidation of the reductant, in this case hypophos-phite, is considered to be under 100% kinetic control. A mixed kinetic-diffusion curve is shown for the reduction of the metal ion, in our case Co2+, in the region close to the mixed potential, Em. Thus, since Co deposition occurs under a condition of mixed kinetic and diffusion control, features small relative to the diffusion layer thickness for Co2+ will experience a higher concentration of the metal ion, and hence... 

The redox potential diagram in eq. 1 illustrates that the effect of optical excitation is to create an excited state which has enhanced properties both as an oxidant and reductant, compared to the ground state. The results of a number of experiments have illustrated that it is possible for the excited state to undergo either oxidative or reductive electron transfer quenching (2). An example of oxidative electron transfer quenching is shown in eq. 2 where the oxidant is the alkyl pyridinium ion, paraquat (3). 

Figure 1.1 (a) Chemical potential diagrams for systems forming a complete range of solid solutions. The tangent shows at its terminal points, X, Y the chemical potentials of the elements x and y which are in equilibrium with the solid solution of composition M (b) Potentials for the system A-B, which forms the two stable compounds the stoichiometric A2B and the non-stoichiometric AB2. The graph shows that there are many pairs of potentials A, B in equilibrium with A2B and only one pair for a particular composition of AB2 AB is metastable with respect to decomposition to A2B and AB2... 

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