Mechanism of recyclization of furans to thiophenes and selenophenes under acid catalysis. 1. Kinetic studies of the reaction of 2,5-dialkylfurans with hydrogen sulfide in the presence of hydrochloric acid

1989 ◽  
Vol 25 (10) ◽  
pp. 1113-1117 ◽  
Author(s):  
S. P. Voronin ◽  
T. I. Gubina ◽  
I. A. Markushina ◽  
V. G. Kharchenko
Keyword(s):  
Hydrogen Sulfide ◽  
Hydrochloric Acid ◽  
Acid Catalysis ◽  
Kinetic Studies

Modification of the Carbon Disulfide Evolution Method for Dithiocarbamate Residues

1969 ◽  
Vol 52 (1) ◽  
pp. 162-167 ◽  
Author(s):  
George E Keppel
Keyword(s):  
Hydrogen Sulfide ◽  
Hydrochloric Acid ◽  
Carbon Disulfide ◽  
Lead Acetate ◽  
Stannous Chloride ◽  
Acetate Solution ◽  
Colorimetric Measurement ◽  
Fungicide Residues ◽  
Mineral Acids ◽  
Lead Acetate Solution

Abstract A study was made of the analytical method for dithiocarbamate fungicide residues based on decomposition by hot mineral acids to the amine and carbon disulfide and colorimetric measurement of the carbon disulfide. Increased recoveries are obtained by the following modifications: adding a reducing agent (stannous chloride) to the sample before treatment with hot acid; svibstituting diluted sodium hydroxide for lead acetate solution to remove hydrogen sulfide and other interferences; and using boiling diluted hydrochloric acid. With these modifications, recoveries of N,N-dimethyldithiocarbamates from crops ranged from 85.3 to 103.8% (average 94.7%). Ethylenebisdithiocarbamates, with the exception of zineb (range 89.1–96.8%, average 92.0%), gave appreciably lower recoveries, indicating further study is necessary.

Terbium(III)-containing organic–inorganic hybrids synthesized through hydrochloric acid catalysis

2009 ◽  
Vol 201 (2-3) ◽  
pp. 214-221 ◽  
Author(s):  
P.P. Lima ◽  
R.A.S. Ferreira ◽  
S.A. Júnior ◽  
O.L. Malta ◽  
L.D. Carlos
Keyword(s):  
Hydrochloric Acid ◽  
Acid Catalysis

Review of Methods for Mercury in Pesticide Formulations

1969 ◽  
Vol 52 (4) ◽  
pp. 764-767
Author(s):  
James E Launer
Keyword(s):  
Acetic Acid ◽  
Hydrogen Sulfide ◽  
Hydrochloric Acid ◽  
Glacial Acetic Acid ◽  
Mercury Compounds ◽  
Pesticide Formulations ◽  
Sulfide Precipitation

Abstract Outlines are given for mercury methods that have been accepted by CIPAC. One method separates mercury from other pesticides by dissolving the pesticide in hot glacial acetic acid and amalgamating the mercury on zinc. Another method dissolves mercury in hydrochloric acid and separates it from other pesticides by hydrogen sulfide precipitation or by amalgamation on zinc. Other oxidation procedures are given for decomposition of mercury compounds. Further study is recommended for the method in which mercury is released with fuming sulfuric-nitric acids and determined with thiocyanate titration.

Corrosion of Refinery Equipment During Acid Cleaning★

CORROSION ◽  
1958 ◽  
Vol 14 (12) ◽  
pp. 43-49 ◽  
Author(s):  
K. R. WALSTON ◽  
A. DRAVNIEKS
Keyword(s):  
Hydrogen Sulfide ◽  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Iron Oxides ◽  
Chemical Cleaning ◽  
Refinery Equipment ◽  
Acid Cleaning ◽  
Corrosion Rates ◽  
Temperature Ranges ◽  
Practical Temperature

Abstract Economical, effective and relatively easy to handle, hydrochloric acid is being widely used as a solvent for chemical cleaning of refinery equipment. Inhibitors must be added to retard corrosion during cleaning operations, but these inhibitors must not prevent dissolution of the scale to be removed. Practical temperature ranges for cleaning are given. The corrosion rate increases exponentially with temperature and with acid concentration. The corrosion .rates of various metals in 5 percent inhibited hydrochloric acid are given. The influence of inhibitors on the rates of dissolution of iron oxides and sulfides are shown. Four typical cases of corrosion occurring during acid cleaning are discussed with special safety precautions that should be observed during cleaning operations. The influence of commonly present substances such as hydrogen sulfide is shown to increase the rate of corrosion. 5.9.2

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