Vibration-spectral studies of compounds formed by the combination of methylformamide and dimethylformamide with some strong acids

1966 ◽  
Vol 19 (11) ◽  
pp. 2091 ◽  
Author(s):  
E Spinner
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Infrared Spectra ◽  
Spectral Studies ◽  
Ionic Form ◽  
Reaction Products ◽  
Unknown Structure ◽  
Acid Reaction ◽  
Strong Acids

A determination of the infrared spectra of the solid hydrochlorides of methylformamide and dimethylformamide and of the Raman spectra of their aqueous solutions showed that certain spectral features change with the medium used. The infrared spectra of the two amides in concentrated and in aqueous sulphuric acid, and in concentrated hydrochloric acid (HCl and DCl), are consistent with the existence of two amide/acid reaction products for each amide: one (certainly ionic) form predominates in sulphuric acid solutions; a second form, of unknown structure, is present in the solid hydrochlorides, and in hydrochloric acid the two forms coexist in equilibrium.

Bioenergy II: Furfural Destruction Kinetics during Sulphuric Acid-Catalyzed Production from Biomass

2009 ◽  
Vol 7 (1) ◽  
Author(s):  
Gianluca Marcotullio ◽  
Miguel A. Tavares Cardoso ◽  
Wiebren De Jong ◽  
Ad H.M. Verkooijen
Keyword(s):  
Sulphuric Acid ◽  
Acid Concentration ◽  
Reaction Products ◽  
Arrhenius Law ◽  
Exponential Factor ◽  
Oil Derivatives ◽  
Destruction Kinetics ◽  
Acid Catalyzed ◽  
Effects Of Temperature

The interest for furfural has increased in the last years due to its potential for competing with oil derivatives as platform chemical. In addition, furfural, derived from C5 sugars, can play a key role in the valorization of the hemicellulose contained in biomass when considering the development of a modern biorefinery concept. The development of such new and competitive biorefinery processes must be based on accurate kinetic data for the reactions involving furfural in the conditions used for its production.This work addresses the determination of furfural destruction kinetics in aqueous acidic environment, using sulphuric acid as catalyst, in the temperature range 150 - 200°C, acid concentration range 36.4 - 145.5 mM and furfural initial concentration between 60.4 and 72.5 mM. These studies were carried out using a recently built lab-scale titanium reactor that enables liquid phase reactions in a relatively broad range of conditions.The obtained results show that destruction of furfural follows first-order reaction kinetics within the range of temperature and acid concentration evaluated. Moreover, the proposed kinetic model takes into account the effects of temperature and acid dilution on the ions activity, and thus H3O+, by using the electrolyte Non-Random Two-Liquid (eNRTL) model. By using this approach, the rate constant dependence on temperature could be described by the Arrhenius law and thus the activation energy could be estimated as being 125.1 [kJ/mol] and the pre-exponential factor 3.71•1011[s-1]. Separation of different reaction products was achieved by means of HPLC, these products were not yet completely identified. Contrarily to what is reported in previous works, formic acid formation from furfural under the tested conditions can be regarded as playing a far less pronounced role than suggested before.

scholarly journals HIDROLISIS RUMPUT LAUT (Glacilaria sp.) MENGGUNAKAN KATALIS ENZIM DAN ASAM UNTUK PEMBUATAN BIOETANOL

Jurnal Kimia ◽  
2016 ◽  
Author(s):  
Yohanes Armawan Sandi ◽  
Wiwik Susanah Rita ◽  
Yenni Ciawi
Keyword(s):  
Gas Chromatography ◽  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Ethanol Concentration ◽  
Reducing Sugar ◽  
Optimum Concentration ◽  
Raw Material ◽  
Optimum Length ◽  
Hydrolysis Of

The aim of this research is to determine the effect of enzyme and acids concentration on the yield of glucose produced in the hydrolysis of Glacilaria sp. in the production of bioethanol. The concentrations of cellulase used were 200 units/mL, 400 units/mL, 600 units/mL, 800 units/mL and the concentration of sulphuric acid (H2SO4) and hydrochloric acid (HCl) used were 1%, 3%, 5%, 7% (w/v). The concentration of reduction sugar was determined using Anthrone and analyzed using UV-Vis spectrophotometry and the determination of ethanol concentration was carried out by using gas chromatography. The results showed that the contents of reducing sugar produced by sulphuric acid (H2SO4) hydrolysis were 26,19%; 36,69%; 41,40%; 45,0% (v/v), by hydrochloric acid (HCl) were 12,12%; 14,03%; 15,17%; 16,50% (v/v), and by cellulase enzyme were 46,15%; 46,73%; 47,68%; 48,25% (v/v). Optimum concentration of reducing sugar produced by hydrolysis using 800 units/mL cellulase was 48,25% (v/v). The optimum length of fermentation to produce bioethanol using Glacilaria sp. as raw material was 5 days. In the fermentation, inoculum with a concentrations of 5% and 10% (w/v) produced 0,85% and 1,51% (v/v) ethanol.

THE DETERMINATION OF ZIRCONIUM WITH BENZOYLPHENYLHYDROXYLAMINE

1960 ◽  
Vol 38 (12) ◽  
pp. 2488-2492 ◽  
Author(s):  
D. E. Ryan
Keyword(s):  
Hydrochloric Acid ◽  
Quantitative Determination ◽  
Sulphuric Acid ◽  
Rare Earths ◽  
Acid Solutions ◽  
Constant Composition ◽  
Hydrochloric Acid Solutions

Zirconium is completely precipitated by benzoylphenylhydroxylamine from 0.5 N acid solutions. The complex formed in sulphuric acid solutions has a constant composition, Zr(C13H10O2N)4, and is used for the direct weighing of zirconium; the factor is 0.0970. The product precipitated from hydrochloric acid solutions must be ignited to the oxide. The reaction is sensitive, 1 p.p.m. of zirconium being detectable, and quantitative determination of 0.2 mg is possible. Thorium and the rare earths do not interfere.

scholarly journals Iron as a disturbing factor in the determination of phosphate by the molybdenum blue method

1954 ◽  
Vol 26 (1) ◽  
pp. 159-168
Author(s):  
Armi Kaila
Keyword(s):  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Ferrous Iron ◽  
Ferric Iron ◽  
Stannous Chloride ◽  
Phosphorus Concentration ◽  
Colour Intensity ◽  
Molybdenum Blue ◽  
Fading Effect

The interference of ferric and ferrous iron in the determination of phosphate by the molybdenum blue method has been studied. It was found that the presence of ferric iron in the solutions could cause either an increase or a decrease in the colour intensity depending on the amount of stannous chloride applied and on the acid and molybdate concentrations in the reagent. Also the phosphorus concentration exerted its effect upon the course of the errors. If the original modification of Truog and Meyer was employed, generally, the most convenient way for the elimination of the interference of ferric iron was to dilute the solution. An increase in the amount of stannous chloride largely helped to prevent the fading effect of ferric iron, provided the phosphorus concentration was not lower than 0.25 ppm. When the effect of ferric iron upon the development of molybdenum blue at various concentrations of sulphuric acid and ammonium molybdate was studied, the observation was made that at each acidity there could be found a concentration of molybdate in which the effect of even fairly high amounts of ferric iron was almost negligible. In lower molybdate concentrations the presence of ferric iron caused an increase in the colour intensity, in higher molybdate concentrations the fading effect of ferric iron was marked. This most suitable level of the molybdate concentration depended to a certain degree on the phosphorus concentration of the solution and on the amount of stannous chloride applied. Fairly good results could be obtained, if the ratio of molybdate (expressed as mg/ml) to acid (expressed as normality) in the solution to be reduced was five times as high as the acidity of the solution to be reduced (expressed as its normality), e.g. 4 in 0.8 N acid, 3.5 in 0.7 N acid, 3 in 0.6 N acid etc. Although it seemed to be fairly possible to avoid the interference of ferric iron by a proper choice of the concentrations of acid and molybdate and of the amount of stannous chloride applied, the fading effect of ferrous iron could not be prevented, if only sulphuric acid was used in the reagents. But the substitution of sulphuric acid by hydrochloric acid totally prevented the fading effect of ferrous iron. On the contrary, a slight increase in the colour intensity was demonstrated. This was true also when only one half of the acid present was hydrochloric acid. It was found that this mixture of sulphuric acid and hydrochloric acid in the molybdate reagent offers an available way for the elimination of the disturbing effect of iron.

Structure Determination of Formic Acid Reaction Products on TiO2(110)†

2004 ◽  
Vol 108 (38) ◽  
pp. 14316-14323 ◽  
Author(s):  
D. I. Sayago ◽  
M. Polcik ◽  
R. Lindsay ◽  
R. L. Toomes ◽  
J. T. Hoeft ◽  
...  
Keyword(s):  
Formic Acid ◽  
Structure Determination ◽  
Reaction Products ◽  
Acid Reaction

Collaborative Study of a Method for the Determination of Antipyrine and Benzocaine in Glycerol and Propylene Glycol Bases

1968 ◽  
Vol 51 (3) ◽  
pp. 624-626
Author(s):  
Richard T Krause
Keyword(s):  
Hydrochloric Acid ◽  
Propylene Glycol ◽  
Ferric Chloride ◽  
Infrared Spectra ◽  
Collaborative Study ◽  
Potassium Bromide ◽  
Reference Standards ◽  
Partition Chromatography ◽  
Average Recovery

Abstract A method for antipyrine and benzocaine, This Journal 50, 685-688 (1967), was studied by ten collaborators on five simulated commercial preparations at levels of 49—54 mg antipyrine/ml and 10—51 mg benzocaine/ml. The antipyrine and benzocaine are separated by column partition chromatography: antipyrine is retained on a ferric chloride column, and benzocaine is retained on a hydrochloric acid column. Maximum absorbances are determined on chloroform eluates at 272 and 283 mμ for antipyrine and benzocaine, respectively. Infrared spectra of the residues are determined in potassium bromide for identification of the drugs. The average recovery for antipyrine was 99.3 ± 1.80%, and for benzocaine, 99.0 ± 1 . 6 0 % . Infrared spectra submitted by collaborators corresponded to the reference standards and showed no interfering peaks. The method, with a slight change in the preparation of the standard solutions, is recommended for adoption as official, first action.

scholarly journals C orrosion Studies on Tinned Iron Plates From Infant Food Cans

2016 ◽  
Vol 13 (2) ◽  
pp. 106-109
Author(s):  
Anima Upadhyay ◽  
M Chandrakala
Keyword(s):  
Acetic Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Sulphuric Acid ◽  
Ammonium Chloride ◽  
Infant Food ◽  
Aggressive Environment ◽  
Metal Plates ◽  
Iron Material ◽  
Strong Acids

The corrosion on smooth tinned iron material has been studied in different media. Solutions of sulphuric acid, hydrochloric acid, acetic acid and salt solutions of ammonium chloride and sodium chloride were prepared to investigate the corrosion on the metal plates. The plates was immersed in the solutions for a period of time same for all the solutions in order to determine the most aggressive environment. Weight loss technique was adopted to study the rate of corrosion. The result reveals that the material got corroded in this order sulphuric acid > hydrochloric acid > acetic acid > ammonium chloride > sodium chloride. It was therefore concluded that the rate of corrosion was high in strong acids compared to the weak acids and salts.

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