scholarly journals THE PREPARATION OF PERCHLORIC ACID FROM SODIUM PERCHLORATE.1

1910 ◽  
Vol 32 (1) ◽  
pp. 66-71 ◽  
Author(s):  
Frank C. Mathers
Keyword(s):  
Perchloric Acid ◽  
Sodium Perchlorate

scholarly journals OXIDATION OF BENZALDEHYDE BY QUINOXALINIUM DICHROMATE

2016 ◽  
Vol 12 (9) ◽  
pp. 4396-4403 ◽  
Author(s):  
K Anbarasu ◽  
N. GEETHA
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Reaction Rate ◽  
Sodium Perchlorate ◽  
Activation Parameters ◽  
Probable Mechanism ◽  
Water Medium ◽  
First Order ◽  
Rate Of Reaction ◽  
Acetic Acid Water

The kinetics and mechanism of oxidation of benzaldehyde by quinoxalinium dichromate has been studied in the presence of perchloric acid in 70 % acetic acid - water medium. The reaction follows first order with respect to benzaldehyde, quinoxalinium dichromate and fractional order with respect to perchloric acid. There is no effect on the reaction rate with increase in ionic strength of the medium by adding sodium perchlorate. The rate of reaction increases with increase in the percentage of acetic acid. The reaction does not induce the polymerization with acrylonitrile. The rate of reaction decreases with increase in the concentration of manganoussulphate. The thermodynamic and activation parameters have been calculated and a probable mechanism has been proposed.

The hydration of mesitylketene in aqueous solution: detection of acid catalysis for an aromatic ketene

1995 ◽  
Vol 73 (4) ◽  
pp. 539-543 ◽  
Author(s):  
J. Andraos ◽  
A.J. Kresge ◽  
N.P. Schepp
Keyword(s):  
Aqueous Solution ◽  
Carbon Atom ◽  
Perchloric Acid ◽  
Reaction Rate ◽  
Acid Catalysis ◽  
Sodium Perchlorate ◽  
Nucleophilic Attack ◽  
Acid Solutions ◽  
Uncatalyzed Reaction ◽  
Acid Catalyzed

Mesitylketene was generated flash photolytically in aqueous solution by the photo-Wolff reaction of 2,4,6-trimethyldiazoacetophenone and also by rearrangement of mesitylynol obtained through photodecarbonylation of mesitylhydroxycyclopropenone, and rates of hydration of this ketene were measured in dilute perchloric acid, sodium perchlorate, and sodium hydroxide solutions as well as in concentrated sodium perchlorate and perchloric acid solutions. In dilute solution only an uncatalyzed reaction and a sodium-hydroxide-catalyzed process were observed, both of which could be attributed to nucleophilic attack, by water and by hydroxide ion, respectively, at the ketene carbonyl carbon atom. In concentrated sodium perchlorate solutions, a mild decrease in reaction rate with increasing salt concentration was observed, as expected on the basis of decreasing water activity and a consequent slowing of the uncatalyzed reaction. A similar mild decrease was found in perchloric acid solutions up to [Formula: see text] but this then gave way to a rate increase that became dominant above [Formula: see text] This appearance of acid catalysis indicates a change in reaction mechanism from nucleophilic attack of water to an electrophilic process involving rate-determining protonation on the β-carbon atom of the ketene group. Analysis of the acid-catalyzed reaction rate by the Cox–Yates method gives the catalytic coefficient [Formula: see text] This, when compared with [Formula: see text] for ketene itself, shows that the mesityl group retards acid-catalyzed hydration by a factor of 2200, and consequently the acid-catalyzed reaction of this, and other aromatic ketenes as well, becomes apparent only under strongly acidic conditions. Keywords: mesitylketene, ketene hydration, acid catalysis, Cox–Yates excess acidity correlation.

Cathodic luminescence of oxide covered aluminium and tantalum electrodes

1977 ◽  
Vol 55 (7) ◽  
pp. 1193-1198 ◽  
Author(s):  
Jouko J. Kankare ◽  
Douglas E. Ryan ◽  
Bernhard J. Fürst
Keyword(s):  
Hydrogen Peroxide ◽  
Triplet State ◽  
Singlet Oxygen ◽  
Perchloric Acid ◽  
Light Emission ◽  
Sodium Perchlorate ◽  
Electrolyte Solutions ◽  
Radiative Transition ◽  
Aluminium Electrode ◽  
Low Amplitude

Cathodic luminescence of oxide covered aluminium and tantalum electrodes in various electrolyte solutions was measured at low amplitude (0 to 10 V) ac excitation. Oxygen or hydrogen peroxide are necessary constituents of the solution for high levels of light emission. For the aluminium electrode in tartrate solutions, copper enhanced light emission at concentrations down to 10 ppb.The tantalum electrode gave fairly high luminescence in solutions containing sodium perchlorate, perchloric acid, and hydrogen peroxide, but copper had no influence on the luminescence output. A mechanism based on the electrogeneration of singlet oxygen and its subsequent radiative transition to the triplet state is suggested.

scholarly journals Oxidative Decarboxylation and Deamination of Essential Amino Acids by Nicotinium Dichromate - A Kinetic Study

2015 ◽  
Vol 45 ◽  
pp. 66-72
Author(s):  
K. Vivekanandan ◽  
R. Lakshmi Narayanan
Keyword(s):  
Amino Acids ◽  
Ionic Strength ◽  
Kinetic Study ◽  
Aqueous Medium ◽  
Perchloric Acid ◽  
Sodium Perchlorate ◽  
Essential Amino Acids ◽  
Oxidative Decarboxylation ◽  
First Order ◽  
Different Temperatures

The oxidation of essential amino acids like valine, leucine, isoleucine, threonine, phenylalanine and histidine using nicotinium dichromate in aqueous medium in presence of perchloric acid at 313 K leads to the formation of corresponding aldehydes. The reaction is first order with respect to nicotinium dichromate, fractional order with respect to amino acids and second order with respect to perchloric acid. Increase in ionic strength by the addition of sodium perchlorate has no effect on the rate constant. There is no polymerization with acrylonitrile. The reaction has been studied at different temperatures and a mechanism confirming to the kinetic observations is suggested.

Equilibria in Acetic Acid: Ion Association Constants of Salts and the Autoprotolysis Constant of Acetic Acid at 105.7°C

1962 ◽  
Vol 15 (3) ◽  
pp. 409 ◽  
Author(s):  
RJL Martin
Keyword(s):  
Acetic Acid ◽  
Perchloric Acid ◽  
Sodium Acetate ◽  
Specific Conductivity ◽  
Ion Pairs ◽  
Sodium Perchlorate ◽  
Ion Association ◽  
Association Constants ◽  
Ion Association Constants

The ion association constants KA=[M+A-]/[M+][A-] which have been measured conductimetrically at 105 7 �C in acetic acid are : perchloric acid 0.0644 X 106, sodium perchlorate 0.1346 x 106, and sodium acetate 0.752 x 106. The parameters 6, centre to centre distance between the ions at contact, which were calculated from Bjerrum's formula, are : perchloric acid 4.52 Ǻ, sodium perchlorate 4.20 Ǻ, and sodium acetate 3.61 Ǻ. The autoprotolysis constant, K = [H2+ Ac][Ac-]= 1.17 x 10-19, was calculated from the specific conductivity of acetic acid at 105.7 �C. The acetic acidium acetate ion pairs were calculated to be 100.0% dissociated.

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