The Solubility of Thorium Hydroxide in Solutions of Sodium Hydroxide and Perchloric Acid at 25°1

1954 ◽  
Vol 76 (23) ◽  
pp. 5938-5940 ◽  
Author(s):  
K. H. Gayer ◽  
H. Leider
Keyword(s):  
Sodium Hydroxide ◽  
Perchloric Acid ◽  
Thorium Hydroxide

Ketonization of the unusually acidic elongated enol generated by flash photolytic decarboxylation of p-formylphenylacetic acid in aqueous solution

2008 ◽  
Vol 86 (2) ◽  
pp. 101-104 ◽  
Author(s):  
Yvonne Chiang ◽  
Kirill Kolmakov ◽  
A Jerry Kresge
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Sodium Hydroxide ◽  
Perchloric Acid ◽  
Flash Photolysis ◽  
Isotope Effects ◽  
Solvent Isotope ◽  
Solvent Isotope Effects

Rates of photolysis of p-formylphenylacetic acid were measured flash photoytically in perchloric acid and sodium hydroxide solutions, and also in acetic acid, biphosphate ion, and tris-(hydroxymethyl)methaneammonium ion buffers, using H2O and D2O as solvents. The results provide rate profiles and solvent isotope effects, which indicate that photolysis occurs through an elongated enol intermediate. This enol is unusually strongly acidic, by some two to three pQa units, when compared with simple non-elongated enols.Key words: flash photolysis, elongated enols, rate profiles, solvent isotope effects.

Colorimetric and Volumetric Assays of Colchicine in Galenicals and in Pharmaceutical Preparations

1975 ◽  
Vol 58 (6) ◽  
pp. 1171-1173 ◽  
Author(s):  
Mohamed S Karawya ◽  
Aly M Diab
Keyword(s):  
Sodium Hydroxide ◽  
Secondary Amine ◽  
Perchloric Acid ◽  
Lithium Aluminum Hydride ◽  
Aluminum Hydride ◽  
Pharmaceutical Preparations ◽  
Amide Group ◽  
Lithium Aluminum

Abstract In the method described the amide group in the colchicine molecule is reduced with lithium aluminum hydride to the corresponding secondary amine. The latter is extracted with chloroform and then determined either colorimetrically by the copper dithiocarbamate reaction or volumetrically by dissolving in acid and titrating with sodium hydroxide or perchloric acid. The results were comparable with those obtained by the Egyptian Pharmacopoeia spectrophotometry method.

scholarly journals The Effect of Some Extraction Solvents on the Chemical Structure of the Starches from tobacco Leaf and Potato Tubers

1962 ◽  
Vol 15 (2) ◽  
pp. 312 ◽  
Author(s):  
NK Matheson ◽  
JM Wheatley
Keyword(s):  
Absorption Spectrum ◽  
Sodium Hydroxide ◽  
Perchloric Acid ◽  
Chemical Structure ◽  
Amylose Content ◽  
Potato Tubers ◽  
Tobacco Leaf ◽  
Iodine Complex ◽  
Extraction Solvents ◽  
Mechanical Extraction

Tobacco leaf starch has been isolated as granules by mechanical extraction, and the viscosity, amylose content, f3-amylolysis limit, starch-iodine complex absorption spectrum, and apparent chain length compared with samples extracted by perchloric acid, sodium hydroxide, and chloral solution and purified as the starch-iodine complex. The efficiency of extraction of these methods was also compared. The same comparisons were made with potato granules and potato granules treated with these extracting reagents.

The 2-oxo-3,3,5,5-tetramethylcyclopentanecarboxylic acid keto–enol system in aqueous solution — Generation of the enol by flash photolytic Wolff rearrangement of 2-diazo-4,4,6,6-tetramethylcyclohexane-1,3-dione followed by hydration of the acylketene thus formed

2005 ◽  
Vol 83 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Y Chiang ◽  
A J Kresge ◽  
V A Nikolaev ◽  
I Onyido ◽  
X Zeng
Keyword(s):  
Aqueous Solution ◽  
Sodium Hydroxide ◽  
Equilibrium Constant ◽  
Perchloric Acid ◽  
Flash Photolysis ◽  
Keto Form ◽  
Wolff Rearrangement ◽  
Buffer Solutions ◽  
Solution Generation ◽  
Oxocarboxylic Acids

Flash photolysis of 2-diazo-4,4,6,6-tetramethylcyclohexane-1,3-dione in aqueous solution produced 2-oxo-3,3,5,5-tetramethylcyclopentylideneketene, which underwent hydration to the enol of 2-oxo-3,3,5,5-tetramethylcyclo pentanecarboxylic acid; the enol then isomerized to the keto form of the acid. Rates of hydration of the ketene and rates of ketonization of the enol were measured in perchloric acid, sodium hydroxide, and buffer solutions, and rate profiles were constructed. Rates of enolization of 2-oxo-3,3,5,5-tetramethylcyclopentanecarboyxlic acid were also measured, using bromine to scavenge the enol as it formed, and rates of enolization and ketonization were then combined to give the keto–enol equilibrium constant pKE = 1.65. This and other results are discussed in comparison with the behavior of the unmethylated 2-oxocyclopentanecarboxylic acid system.Key words: flash photolysis, photo-Wolff reaction, ketene hydration, enolization, ketonization, keto–enol equilibria, β-oxocarboxylic acids.

THE SOLUBILITY OF URANIUM(IV) HYDROXIDE IN SOLUTIONS OF SODIUM HYDROXIDE AND PERCHLORIC ACID AT 25 °C

1957 ◽  
Vol 35 (1) ◽  
pp. 5-7 ◽  
Author(s):  
K. H. Gayer ◽  
H. Leider
Keyword(s):  
Sodium Hydroxide ◽  
Perchloric Acid ◽  
Acid Solutions ◽  
Hydroxide Water

The solubility of uranium(IV) hydroxide has been measured in sodium hydroxide, water, and perchloric acid solutions. A possible reaction in sodium hydroxide solutions is evaluated.

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