Aqueous Solutions Of Sulphur Dioxide Research Articles

Simultaneous solubility of SO 2 and NH 3 in (salt + H 2O) and enthalpy change upon dilution of (SO 2 + NH 3 + salt + H 2O) in (salt + H 2O) {salt = (NH 4) 2SO 4 or Na 2SO 4}: Experimental results and model predictions

The simultaneous solubility of sulfur dioxide and ammonia in aqueous solutions of (ammonium sulfate or sodium sulfate) was measured by a synthetic method in the temperature range from 313.6 to 373.2 K and at pressures up to 2.5 MPa. Furthermore, the enthalpy change upon diluting aqueous solutions of sulfur dioxide, ammonia and (ammonium sulfate or sodium sulfate) in aqueous solutions of the same salt was measured in a batch calorimeter at about 313 and 352 K. The experimental results are used for comparison with predictions from a thermodynamic model for the vapor–liquid equilibrium and the enthalpy of dilution of those chemical reacting systems. In that model, activity coefficients are calculated from Pitzer's molality-scale-based Gibbs excess energy model, where all interaction parameters are either adopted from previous investigations on the properties of the binary and ternary sub-systems (if available) or they are neglected (if they are not available).

Enthalpy of dilution of [SO 2 + salt + H 2O] in [salt + H 2O] {salt = (NH 4) 2SO 4 or Na 2SO 4}: Experimental results and modeling

New experimental results are presented for the enthalpy change upon diluting aqueous solutions of sulfur dioxide containing a salt (either ammonium sulfate or sodium sulfate) in aqueous solutions of that salt at about 313 and 352 K. A previously developed thermodynamic model for the vapor–liquid equilibrium of the chemical reacting systems {SO 2 + (NH 4) 2SO 4 + H 2O} and (SO 2 + Na 2SO 4 + H 2O) is extended allowing for the formation of pyrosulfite and for the description of the new experimental results for the enthalpy change upon dilution.

Enthalpy of dilution of (SO 2 + H 2O) and (SO 2 + NH 3 + H 2O) in pure water: experimental results and modeling

New experimental results for the enthalpy change upon diluting aqueous solutions of sulfur dioxide as well as aqueous solutions of sulfur dioxide and ammonia in pure water at about 313 and 352 K are presented. The experimental results are used to modify a previously developed thermodynamic model for the vapor–liquid equilibrium of the chemical reacting system (SO 2 + NH 3 + H 2O). That model is extended allowing on the one side for the formation of pyrosulfite, and on the other side for the description of experimental results for the enthalpy change upon dilution (in pure water) of (NH 3 + H 2O) (taken from the literature), as well as (SO 2 + H 2O) and (SO 2 + NH 3 + H 2O) (from the present work).

Leaching of a rich Greek manganese ore by aqueous solutions of sulphur dioxide

A rich manganese ore from Chalkidiki (Greece) was leached in aqueous SO 2 solutions at atmospheric pressure and ambient temperature to extract more than 95% Mn after 10 min. Process conditions, such as SO 2 concentration, time, pH, agitation rate, temperature and pulp density were investigated. Low impurities of iron in the pregnant solution were observed and the process seems to be attractive for manganese extraction from this ore.

Leaching of cobalt and molybdenum from a Co-Mo/γ-Al2O3 hydrodesulphurization catalyst waste with aqueous solutions of sulphur dioxide

Cobalt and molybdenum can be easily extracted from the Co-Mo/γ-Al2O3 waste hydrodesulphurization (HDS) catalyst using aqueous solutions of SO2. Both Co and Mo readily dissolve, almost completely if the waste catalyst is calcinated at 923 K for 6 h prior to dissolution. The dissolution is very rapid at ambient temperature and it is completed in only 8 min.The rate data for molybdenum leaching fits the equation: 1 − (2α3) − (1 − α)23 = kt.Diffusion through the alumina layer controls the rate.The leaching of cobalt is slower than that of molybdenum and the experimental data fits the rate equation: 1 − (2α3) − (1 − α)23 + (βro) [1 − {1 − α}13] = ktThe data indicates that the dissolution rate of cobalt is governed by a mixed kinetic control; i.e. diffusion through the alumina layer plus reaction at the interface are rate determining factors.

PH Effects on the pulse radiolysis of deoxygenated aqueous solutions of sulphur dioxide

Dilute deoxygenated aqueous solutions of sulphur dioxide and its related anions HSO–3 and SO2–3 in the pH-range 2–11 were pulse irradiated and the time dependence of the transient optical absorptions and electrical conductance recorded. Hydrogen atoms and OH radicals abstract hydrogen from HSO–3. Also OH radicals react with SO2 and SO2–3 to form the radical ion SO–3˙ with an absorption maximum at 255 nm. The SO–3˙ radical ions recombine to form sulphate (SO2–4) and dithionate (S2O2–6), the reaction rate and relative proportions of products being pH-dependent. In acid solutions the SO–2˙ radical ion with an absorption maximum at 360 nm is also formed, presumably by reaction of hydrogen atoms with sulphur dioxide. The SO–2˙ radical ions recombine to form dithionite (S2O2–4).

The Determination of Small Quantities of Sulphate and Thiosulphate in Aqueous Solutions of Sulphur Dioxide.

The Determination of Small Quantities of Sulphate and Thiosulphate in Aqueous Solutions of Sulphur Dioxide.

Direct Spectrophotometric Determination of Sulphate in Aqueous Solutions of Sulphur Dioxide.

Direct Spectrophotometric Determination of Sulphate in Aqueous Solutions of Sulphur Dioxide.

Diffusion studies in aqueous solutions of sulfur dioxide

Measurements of the over-all or effective diffusion coefficients of aqueous solutions of sulfur dioxide at 21°C have been made using 35S as tracer. The experiments were carried out over the concentration range (0·016–1·78)M. Also the effective diffusion coefficients of 0·2 M sulfur dioxide solutions in 3·5 M NaClO 4 medium have been measured at different pH values. The diffusion coefficients found here can not be ascribed to any one diffusing species but should be treated as concentration weighted means of the self-diffusion coefficients of the species found in the solutions. On the basis of the equilibrium constants for sulfur dioxide solutions in 3·5M NaClO 4 medium the concentration ratios of sulfur dioxide, hydrogen sulfite ions and sulfite ions and hence the over-all diffusion coefficient of the sulfur dioxide solutions are obtained as a function of pH. By fitting this equation to the experimental results the single diffusion coefficients of sulfur dioxide, hydrogen sulfite ions and sulfite ions are calculated.

Relaxation effects in aqueous solutions of sulphur dioxide

Absorption of ultrasonic energy by solutions of sulphur dioxide ammonia and carbon dioxide in water, and in the case of the first gas in several other organic solvents, has been studied by the pulse technique. Aqueous sulphur dioxide solutions exhibit a relaxation phenomenon in the frequency range of 2 to 15 Mc/s. as evidenced by the absorption (α λ) showing a peak in this region when plotted against frequency. This peak occurs at higher frequencies for higher concentrations upto a limit after which the peak absorption frequency does not change with concentration. These observations, along with the fact that no such effect is observed in the case of other solvents, lead to the conclusion that the phenomenon is caused by a change in the dynamic equilibrium between H2SO3 molecules and H+ and HSO3− ions in the presence of the sound beam. The absence of a similar effect in the case of ammonia and carbon dioxide solutions which also involve a chemical reaction is explained on the basis of the widely differing relaxation times of the three gases.

AN INVESTIGATION OF THE EQUILIBRIA EXISTING IN GAS-WATER SYSTEMS FORMING ELECTROLYTES

The data and theoretical treatment contained in this paper are the continuation of a series of researches instituted to investigate the equilibria existing in certain gaseous-aqueous systems. In this work the vapor pressures and electrolytic conductivities of aqueous solutions of sulphur dioxide, carbon dioxide, and ammonia have been measured with greater precision than ever before over a temperature range from 0 to 25 °C. and over a concentration range where their respective vapor pressures do not exceed one atmosphere. From the data thus derived, equilibria relations have been calculated and certain changes have been made in the mode of theoretical procedure involved in this type of calculation.With regard to the equilibria existing in the three systems, the conclusions drawn may be summarized as follows: Practically all of the ammonia exists in the combined form and practically all the carbon dioxide exists as free carbon dioxide in the aqueous solutions in the temperature range investigated. The amounts of free and combined sulphur dioxide are of the same order of magnitude and the relative amount of combined and free sulphur dioxide can be calculated approximately, the latter increasing markedly with rising temperature. The true dissociation constant can therefore be found for ammonium hydroxide, can be estimated for sulphurous acid, but cannot be calculated for carbonic acid from the available data.

The Ultraviolet Absorption Spectra of Aqueous Solutions of Sulphur Dioxide and some of its Derivatives

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Ultraviolet Absorption Spectra of Aqueous Solutions of Sulphur Dioxide and some of its DerivativesF. H. GetmanF. H. GetmanMore by F. H. GetmanCite this: J. Phys. Chem. 1926, 30, 2, 266–276Publication Date (Print):February 1, 1926Publication History Published online1 May 2002Published inissue 1 February 1926https://doi.org/10.1021/j150260a008RIGHTS & PERMISSIONSArticle Views154Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (696 KB) Get e-Alerts