Ionization of moderately strong acids in aqueous solution. Part III. Methane-, ethane-, and propanesulfonic acids at 25�C

1974 ◽  
Vol 3 (8) ◽  
pp. 603-617 ◽  
Author(s):  
Arthur K. Covington ◽  
Richard Thompson
Keyword(s):  
Aqueous Solution ◽  
Strong Acids

Ionization of moderately strong acids in aqueous solution. I. Trifluoro- and trichloroacetic acids

1970 ◽  
Vol 74 (21) ◽  
pp. 3773-3780 ◽  
Author(s):  
Arthur K. Covington ◽  
J. G. Freeman ◽  
T. H. Lilley
Keyword(s):  
Aqueous Solution ◽  
Strong Acids

ChemInform Abstract: STRUCTURE OF MODERATELY STRONG ACIDS IN AQUEOUS SOLUTION

1982 ◽  
Vol 13 (1) ◽  
Author(s):  
R. I. GELB ◽  
L. M. SCHWARTZ ◽  
D. A. LAUFER
Keyword(s):  
Aqueous Solution ◽  
Abstract Structure ◽  
Strong Acids

scholarly journals Synthesis of fluorinated phosphonic, sulfonic, and mixed phosphonic/sulfonic acids

1989 ◽  
Vol 67 (11) ◽  
pp. 1795-1799 ◽  
Author(s):  
Debao Su ◽  
Wenbiao Cen ◽  
Robert L. Kirchmeier ◽  
Jean'ne M. Shreeve
Keyword(s):  
Aqueous Solution ◽  
Elevated Temperature ◽  
Mass Spectroscopy ◽  
Sulfonic Acids ◽  
Phosphonic Acids ◽  
Degree Of Stability ◽  
High Degree ◽  
Strong Acids ◽  
Acid Precursor

The acids (HO)2P(O)CFHSO3H, (HO)2P(O)(CF2)4O(CF2)2SO3H, H(CF2)2O(CF2)2P(O)(OH)2, H(CF2)2O(CF2)4P(O)(OH)2, (HO)2P(O)(CF2)2O(CF2)4H, and the acid precursor (C2H5O)2P(O)CF(SO3Na)2 have been synthesized. Elemental analysis, 19F, 1H, and 31P NMR, and mass spectroscopy were used for characterization of these materials. They are very strong acids, and exhibit a high degree of stability in aqueous solution at elevated temperature, which makes them attractive candidates for use as electrolytes in fuel cells. Keywords: fluorinated phosphonic acids; fluorinated sulfonic acids; 1H, 19F, 31P NMR.

scholarly journals The differential titration of mixed strong and weak acids. A method for "free HCl" in gastric contents, etc

1934 ◽  
Vol 115 (792) ◽  
pp. 170-180 ◽  
Keyword(s):  
Aqueous Solution ◽  
Strong Acid ◽  
Practical Method ◽  
Potassium Citrate ◽  
Simple Modification ◽  
Potassium Tartrate ◽  
Inorganic Acids ◽  
Gastric Contents ◽  
Peptic Digestion ◽  
Strong Acids

It is frequently convenient to be able to distinguish between strong inorganic acids and weaker acids present in the same aqueous solution. Biochemically, such a distinction is required in analysing gastric contents for "free HCl," in titrating blood for "organic acids," in determining free acidity during the course of peptic digestion, and so on. Chemically, it is useful to be able to estimate by direct acid titration moderately strong acid groups combined as salts (such as sodium acetate, sodium potassium tartrate, potassium citrate, lead acetate, etc.). Available methods were either entirely approximate or even positively inaccurate. To remedy this position, a simple modification affording considerable quantitative improvement is now proposed. The difficulty common to current methods (see Hawk, 1931; Hollander, 1931) is chiefly that of distinguishing strong acids (fully dissociated) from other unknown acids only slightly less strong (not fully dissociated), by an endpoint which depends on p H alone. No new choice of indicator can improve the quantitative uncertainty as to how far these unknown moderately strong acids have participated as "strong acids" in an estimation, and, in fact, no improvement is possible unless the acidity of the moderately strong acids is so depressed as to minimize the extent of their interference. The inherent advantage of titration in non-aqueous solvents over ordinary aqueous titrations in this direction has long been realized (Bishop, Kittredge, and Hildebrand, 1922); but the procedure cannot be used in biochemical estimations, where the experimental material is in aqueous solution. Yet it is strange that the obvious device—the basis of which was established by Cray and Westrip (1925)—of adding miscible organic solvents (acetone) to these aqueous solutions, has not been adequately exploited as a simple practical method. Preliminary notice of such adaptation has already been given (Richardson, 1932), but detailed presentation has been delayed to permit treatment of other aspects of mixed solvent titration (p. 121).

Structure of moderately strong acids in aqueous solution

1981 ◽  
Vol 103 (19) ◽  
pp. 5664-5673 ◽  
Author(s):  
Robert I. Gelb ◽  
Lowell M. Schwartz ◽  
Daniel A. Laufer
Keyword(s):  
Aqueous Solution ◽  
Strong Acids

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

Sign in / Sign up

Export Citation Format

Share Document