Bisulfate ions

Here the values of a are the activities of the designated ions in solution, and and are the equiHbrium constants for the dissociation reactions. is infinity because dissociation to hydrogen and bisulfate ions is essentially complete. The best value for is probably 0.0102 (17). Thus sulfuric acid contains a mixture of hydrogen, bisulfate, and sulfate ions where the ratios of these ions vary with concentration and temperature. 

To adjust the activities of sulfuric acid to the convention which assumes that the acid dissociates only partiaUy into hydrogen and bisulfate ions, the... 

The hydrolysis equilibria for H2Cr04 given in Table 3 are only valid in HNO or HCIO solutions. Other acids yield complexes such as those shown for chloride and bisulfate ions. The exact composition of chromate(VI) anion(s) present in aqueous solution is a function of both pH and hexavalent chromium concentration (68). However, at pH values above 8, virtually all the Cr(VI) is present as the CrO anion. When the pH is between 2 and 6, an equilibrium mixture of HCrO and Ci2 is present when the pH is below 1, the principal species is H2Cr04 (68,69). At very high Cr(VI) concentrations... 

Conductivity due to similar proton jumps is present in other solvents. Consider a bisulfate ion dissolved in sulfuric acid. The relation between... 

Reduction by sodium dithionite. A small amount of sodium dithionite, solid or in solution, is added to a luciferase solution made with 50 mM phosphate, pH 7.0, containing 50 pM FMN. The amount of dithionite used should be minimal but sufficient to remove oxygen in the solution and to fully reduce the flavin. The solution made is injected into an air-equilibrated buffer solution containing a long-chain aldehyde and luciferase to initiate the luminescence reaction. With this method, the reaction mixture will be contaminated by bisulfite and bisulfate ions derived from dithionite. 

N-nitro amines, RNHN02, decompose to alcohols and nitrous oxide in strong acid media. Rate constants obtained for R = methyl in sulfuric acid222 224 are illustrated as excess acidity plots in Fig. 12.119 This shows multiple curvature, but analysis according to equation (59) shows that one water molecule is involved in the reaction up to about 80 wt% H2S04, and one bisulfate ion above this point, see Fig. 13. The proposed mechanism is shown in Scheme 2. 19... 

Fig. 13 Excess acidity plot against X for the decomposition of jV-nitromethylamine in aqueous H2S04 at 25°C. Data of Fig. 12, assuming the involvement of one water molecule (left-hand line) at low acidities, and of one bisulfate ion (right-hand line, triangles) at high acidities.

Fig. 15.8. Results of reacting 02 at 100 °C into a system containing pyrite. Pyrite dissolves (top) with addition of 02. The reaction (bottom) produces bisulfate ions and ferric species (FeCl+ and Fe++), which in turn are consumed at the end of the path to form hematite.

Dickson et al. [5], calculated the Gibbs function for the ionization of the bisulfate ion by measurement of cell potentials in the temperature range from 50° to 250°C. They found that the Gibbs function could be represented by the equation... 

In sulfuric acid solution, the structure observed at potentials more positive than the first UPD peak was assigned to the adsorbed bisulfate ions. After the first... 

Standard solutions of sulfuric acid and sodium bisulfate were used to adjust the concentrations of hydrogen ion, bisulfate ion, and sulfate ion. [The concentrations of... 

Fig. 6.93. A typical equilibrium configuration for a model of bisulfate adsorption on Rh(111), generated by Monte Carlo methods in the ordered (-

What information can be obtained from A/ ds One important parameter involved in the enthalpy of the reaction is the ion-metal bond. However, A7 ds includes all the different interactions involved in the adsorption process, e.g., the breaking of the hydration sheet of the electrode and the ion, lateral interactions, and heterogeneity of the surface. One can subtract all these energy terms from AH ds and obtain in this way the energy (or strength) of the ion-metal bond. For the example of the adsorption of bisulfate ions onpolycrystalline platinum (Fig. 6.105), the ion-metal bond was found to be -214 60 kJ mol-1. 

Experimental parameters were obtained from the adsorbance of bisulfate ions on polyciystalline electrodes using a radiotracer technique slightly different from that described in the text, where the working electrode is placed on top of the scintillator. These values are listed in Table P.l. 

HS04 Hydrogen sulfate (bisulfate) ion S042- Sulfate ion... 

Sulfuric acid dissociates, giving a proton plus the bisulfate ion. 

The discussion in the previous sections concerning solvated species indicates that a complete knowledge of the chemical reactions that take place in a system is not necessary in order to apply thermodynamics to that system, provided that the assumptions made are applied consistently. The application of thermodynamics to sulfuric acid in aqueous solution affords another illustration of this fact. We choose the reference state of sulfuric acid to be the infinitely dilute solution. However, because we know that sulfuric acid is dissociated in aqueous solution, we must express the chemical potential in terms of the dissociation products rather than the component (Sect. 8.15). Either we can assume that the only solute species present are hydrogen ion and sulfate ion (we choose to designate the acid species as hydrogen rather than hydronium ion), or we can take into account the weak character of the bisulfate ion and assume that the species are hydrogen ion, bisulfate ion, and sulfate ion. With the first assumption, the effect of the weakness of the bisulfate ion is contained in the mean activity coefficient of the sulfuric acid, whereas with the second assumption, the ionization constant of the bisulfate ion is involved indirectly. 

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