EQUILIBRIA IN SULPHUR DIOXIDE SOLUTIONS

1930 ◽  
Vol 2 (1) ◽  
pp. 42-64 ◽  
Author(s):  
W. Boyd Campbell ◽  
O. Maass
Keyword(s):  
Aqueous Solutions ◽  
Sulphur Dioxide ◽  
Current Practice ◽  
Water Solution ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Vapor Pressures ◽  
Hydrogen Ion Concentration ◽  
Temperature Range ◽  
Free Sulphur

The investigation described deals with the equilibria existing in a water solution of sulphur dioxide. The vapor pressures and conductivities of solutions of sulphur dioxide were measured over the temperature range 23° to 135 °C. at various concentrations up to 8%. The densities of the aqueous solutions up to 15% were also measured. A discussion of the various equilibria in the light of these data leads to the conclusion that sulphurous acid is one of considerable strength, its apparent weakness being due to the small amount of H2SO3 actually present. With rise in temperature the free sulphur dioxide increases and the hydrogen-ion concentration of the sulphite liquor used in current practice is so low that it seems highly improbable that the cooking reaction is due essentially to this factor. Apart from the bearing this work may have on the theory of sulphite cooking and the theory of the equilibria existing in the SO2−H2O system, it fills a considerable gap in the data regarding sulphur dioxide.

scholarly journals THE ELIMINATION OF DISCREPANCIES BETWEEN OBSERVED AND CALCULATED P.D. OF PROTEIN SOLUTIONS NEAR THE ISOELECTRIC POINT WITH THE AID OF BUFFER SOLUTIONS

1922 ◽  
Vol 4 (5) ◽  
pp. 617-619 ◽  
Author(s):  
Jacques Loeb
Keyword(s):  
Aqueous Solution ◽  
Aqueous Solutions ◽  
Isoelectric Point ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Protein Solutions ◽  
Protein Solution ◽  
Hydrogen Ion Concentration ◽  
Buffer Salt ◽  
Buffer Solutions

1. It had been noticed in the previous experiments on the influence of the hydrogen ion concentration on the P.D. between protein solutions inside a collodion bag and aqueous solutions free from protein that the agreement between the observed values and the values calculated on the basis of Donnan's theory was not satisfactory near the isoelectric point of the protein solution. It was suspected that this was due to the uncertainty in the measurements of the pH of the outside aqueous solution near the isoelectric point. This turned out to be correct, since it is shown in this paper that the discrepancy disappears when both the inside and outside solutions contain a buffer salt. 2. This removes the last discrepancy between the observed P.D. and the P. D. calculated on the basis of Donnan's theory of P.D. between membrane equilibria, so that we can state that the P.D. between protein solutions inside collodion bags and outside aqueous solutions free from protein can be calculated from differences in the hydrogen ion concentration on the opposite sides of the membrane, in agreement with Donnan's formula.

THE EFFECT OF SULPHITE LIQUOR COMPOSITION ON THE RATE OF DELIGNIFICATION OF SPRUCE WOOD AND YIELD OF PULP

1937 ◽  
Vol 15b (11) ◽  
pp. 457-474 ◽  
Author(s):  
J. M. Calhoun ◽  
F. H. Yorston ◽  
O. Maass
Keyword(s):  
Sulphur Dioxide ◽  
Lignin Content ◽  
Order Relation ◽  
Ion Concentration ◽  
Quantitative Relation ◽  
Systematic Deviation ◽  
Hydrogen Ion Concentration ◽  
First Order ◽  
Spruce Wood ◽  
Free Sulphur

A technique has been devised for studying the delignification of wood in sulphite liquor under accurately controlled conditions. The rate of delignification of resin extracted spruce wood-meal has been determined at 130 °C. over the concentration range 0.2 to 1.4% combined, and 2 to 14% total, sulphur dioxide. The reaction shows a systematic deviation from the first order relation that is the same for any composition of liquor. A quantitative relation between the rate of delignification and the concentration of free sulphur dioxide, or better, the partial pressure of sulphur dioxide gas, has been established. The nature and significance of this relation is discussed in connection with the mechanism of the delignification process. It has been shown that the hydrogen ion concentration alone does not determine the rate of cooking, but evidence is presented that indicates that the product of the concentrations of the hydrogen and bisulphite ions is the controlling factor.The yield of pulp for any given lignin content is independent of the free sulphur dioxide over the whole concentration range, but increases in a marked manner with the concentration of the combined. An explanation is offered, and the practical aspects are pointed out.

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

1931 ◽  
Vol 5 (2) ◽  
pp. 162-199 ◽  
Author(s):  
O. M. Morgan ◽  
O. Maass
Keyword(s):  
Carbon Dioxide ◽  
Aqueous Solutions ◽  
Sulphur Dioxide ◽  
Carbonic Acid ◽  
Ammonium Hydroxide ◽  
Theoretical Treatment ◽  
Vapor Pressures ◽  
Temperature Range ◽  
Free Carbon Dioxide ◽  
Order Of Magnitude

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 INFLUENCE OF HYDROGEN ION CONCENTRATION WITH PRETREATMENT OF WOOD ON ITS SUBSEQUENT DELIGNIFICATION

1935 ◽  
Vol 13b (5) ◽  
pp. 289-295 ◽  
Author(s):  
A. J. Corey ◽  
O. Maass
Keyword(s):  
Previous Investigation ◽  
Ph Value ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Forced Flow ◽  
Effect Of Temperature ◽  
Hydrogen Ion Concentration ◽  
Temperature Range ◽  
Wood Meal ◽  
Buffer Solutions

The results obtained by the authors in a previous investigation have been checked. The influence of an acid, a salt and a base on the pretreatment of wood at 130 °C. has been determined. It is shown that pretreatment of wood meal decreases the rate of subsequent delignification. Pretreatment was carried out over the temperature range 100° to 140 °C. and the effect of temperature is shown to be very marked. As it was found that the pH of the water after pretreatment decreased, pretreatment was carried out on a chip in which the pH was kept more constant by a forced flow of water through the chip. It is shown that the rate of delignification is increased. Pretreatment was carried out in buffer solutions and it is shown that there is a pH value for which the influence of pretreatment is a minimum. The inferences drawn in connection with sulphite cooking are briefly discussed.

STUDIES IN THE SYSTEM CALCIUM-OXIDE–SULPHUR-DIOXIDE–WATER: III. PRECIPITATION TEMPERATURES

1935 ◽  
Vol 13b (6) ◽  
pp. 370-379 ◽  
Author(s):  
P. E. Gishler ◽  
O. Maass
Keyword(s):  
Calcium Oxide ◽  
Sulphur Dioxide ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Buffer Solution ◽  
Hydrogen Ion Concentration ◽  
Ion Concentrations ◽  
Precipitation Temperature ◽  
Colloidal Matter ◽  
Considerable Concentration

A technique is described for measuring the precipitation temperatures of the system calcium-oxide–sulphur-dioxide–water, and the results over a considerable concentration range are tabulated. It is shown that the presence of colloidal matter brings about a condition of supersaturation. The hydrogen ion and bisulphite ion concentrations for the solutions at the precipitation temperature have been calculated. It is suggested that the hydrogen ion concentration plays an important role in precipitation, and the copious nature of the precipitation with rising temperature above the precipitation temperature is explained.A table containing bisulphite ion concentrations over a large range of calcium oxide and sulphur dioxide concentrations, and over the temperature range 50–90 °C., is given. It is pointed out that the system calcium-oxide–sulphur-dioxide–water acts as a buffer solution so far as bisulphite ions are concerned.

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