scholarly journals Kinetika Reaksi Hidrolisis Pati Biji Alpukat (Persea americana Mill) dengan Katalis HCl

2020 ◽  
Vol 4 (1) ◽  
pp. 120-131
Author(s):  
Sitti Rahmawati ◽  
Asnila Asnila ◽  
Suherman Suherman ◽  
Paulus Hengky Abram
Keyword(s):  
Reaction Order ◽  
Second Order ◽  
Hydrolysis Reaction ◽  
Starch Hydrolysis ◽  
First Order ◽  
Graph Method ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Avocado Seed

One of the plants that can be used as raw material for making sugar is plants that contain starch content such as avocado seeds. This study aims to determine the reaction order, the reaction rate constant from the hydrolysis of avocado seed starch using HCl. The method of this research is to determine the optimum concentration of HCl hydrolysis reaction from avocado seed starch using various concentrations of HCl (0.5 M; 1 M; 1.5 M; 2 M; 2.5 M) at the optimum temperature and stirring time (90oC for 70 minute). The hydrolysis process was followed by neutralization using 5 M NaOH solution and evaporated to obtain concentrated glucose, glucose was analyzed qualitatively and quantitatively by the Benedict method and the phenol sulfuric acid method. Based on the results of the maximum glucose levels obtained from the hydrolysis of variations in the concentration of HCl avocado seed starch, HCl 1.5 M. Furthermore, determine the kinetics of the starch hydrolysis reaction using time variations (30, 40, 50, 60 and 70) minutes at 90oC and concentrations The HCl 1.5 M. reaction order is determined by the intral method and the graph method. Determination of the first order graph method is done by plotting the value of ln [A] versus time, while the second order by plotting the value of 1 / [A] versus time. The first order with a 93% confidence level was obtained from the value of R2 = 0.9312, while the second order was 85% obtained from the value of R2 = 0.8581. Determination of the order of the integral method k value tends to remain in the first order formula with an average of k = 0.01962 minutes-1. Based on the two methods, it can be determined that the kinetics of the avocado seed starch hydrolysis reaction follows a first-order reaction.

The kinetics of the thermal decomposition of normal paraffin hydrocarbons - V. Order of reaction over extended ranges of pressure

1952 ◽  
Vol 214 (1116) ◽  
pp. 20-35 ◽  
Keyword(s):  
Activation Energy ◽  
Reaction Order ◽  
Initial Pressure ◽  
Important Change ◽  
Second Order ◽  
Relative Probability ◽  
First Order ◽  
Molecular Reaction ◽  
Single Transition ◽  
Kinetics Of

Previous papers have provided evidence that the decomposition of a paraffin reduced to its limiting rate by nitric oxide is a molecular reaction. This reaction has an unusual pressure dependence, which has now been studied over a wider range, namely, up to 1600 mm, and down to 0⋅1 mm. In the higher part of the pressure range the reaction order changes from nearly the second to the first with increase in the initial pressure, as now confirmed by extended measurements on n -butane and n -pentane. In the lower part of the range another transition from second order to first with rise of pressure can be found, and is here shown by measurements on ethane, propane, n -butane, n -pentane and n -hexane. Thus with higher normal paraffins the reaction order is the second at the lowest pressure, decreases to the first, increases again towards the second and finally returns to the first at the highest pressure. Where this behaviour is shown the activation energy is also a function of the pressure. The activation energy for ethane is not a function of the pressure and, correspondingly, there is here a single transition from the second order at the lowest pressure to the first order at about 400 mm and up to at least 1600 mm. Over the range of pressure where the composite behaviour is observed, mass spectrometer analysis of the butane products reveals no important change in the relative probability of rupture at the C 1-2 and C 2-3 linkages respectively. In the region of the lower pressures, however, some of the primarily formed ethane splits to give ethylene and hydrogen more rapidly than can be accounted for by the decomposition rate of ethane as directly determined for comparable conditions.

Evidence for general base catalysis by protic solvents in a kinetic study of alcoholyses and hydrolyses of 1-(phenoxycarbonyl)pyridinium ions under both solvolytic and non-solvolytic conditions

2009 ◽  
Vol 74 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Dennis N. Kevill ◽  
Byoung-Chun Park ◽  
Jin Burm Kyong
Keyword(s):  
Second Order ◽  
Base Catalysis ◽  
Substitution Reactions ◽  
Third Order ◽  
Methoxy Derivative ◽  
First Order ◽  
General Base ◽  
Protic Solvents ◽  
Kinetics Of ◽  
Pyridinium Ions

The kinetics of nucleophilic substitution reactions of 1-(phenoxycarbonyl)pyridinium ions, prepared with the essentially non-nucleophilic/non-basic fluoroborate as the counterion, have been studied using up to 1.60 M methanol in acetonitrile as solvent and under solvolytic conditions in 2,2,2-trifluoroethan-1-ol (TFE) and its mixtures with water. Under the non- solvolytic conditions, the parent and three pyridine-ring-substituted derivatives were studied. Both second-order (first-order in methanol) and third-order (second-order in methanol) kinetic contributions were observed. In the solvolysis studies, since solvent ionizing power values were almost constant over the range of aqueous TFE studied, a Grunwald–Winstein equation treatment of the specific rates of solvolysis for the parent and the 4-methoxy derivative could be carried out in terms of variations in solvent nucleophilicity, and an appreciable sensitivity to changes in solvent nucleophilicity was found.

Determination of the Nucleophilicity of Tricarbonyliron Coordinated Cyclohepta-1,3,5-triene

1999 ◽  
Vol 64 (11) ◽  
pp. 1770-1779 ◽  
Author(s):  
Herbert Mayr ◽  
Karl-Heinz Müller
Keyword(s):  
Gibbs Energy ◽  
Ambient Temperature ◽  
Rate Constants ◽  
Second Order ◽  
Order Rate ◽  
Electrophilic Additions ◽  
Kinetics Of

The kinetics of the electrophilic additions of four diarylcarbenium ions (4a-4d) to tricarbonyl(η4-cyclohepta-1,3,5-triene)iron (1) have been studied photometrically. The second-order rate constants match the linear Gibbs energy relationship log k20 °C = s(E + N) and yield the nucleophilicity parameter N(1) = 3.69. It is concluded that electrophiles with E ≥ -9 will react with complex 1 at ambient temperature.

scholarly journals Kinetics of Phenolic Compounds Modification during Maize Flour Fermentation

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6702
Author(s):  
Oluwafemi Ayodeji Adebo ◽  
Ajibola Bamikole Oyedeji ◽  
Janet Adeyinka Adebiyi ◽  
Chiemela Enyinnaya Chinma ◽  
Samson Adeoye Oyeyinka ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Phenolic Acids ◽  
Kinetic Models ◽  
Titratable Acidity ◽  
Second Order ◽  
Soluble Solids ◽  
Maize Flour ◽  
First Order ◽  
Compound Modification ◽  
Kinetics Of

This study aimed to investigate the kinetics of phenolic compound modification during the fermentation of maize flour at different times. Maize was spontaneously fermented into sourdough at varying times (24, 48, 72, 96, and 120 h) and, at each point, the pH, titratable acidity (TTA), total soluble solids (TSS), phenolic compounds (flavonoids such as apigenin, kaempferol, luteolin, quercetin, and taxifolin) and phenolic acids (caffeic, gallic, ferulic, p-coumaric, sinapic, and vanillic acids) were investigated. Three kinetic models (zero-, first-, and second-order equations) were used to determine the kinetics of phenolic modification during the fermentation. Results obtained showed that fermentation significantly reduced pH, with a corresponding increase in TTA and TSS. All the investigated flavonoids were significantly reduced after fermentation, while phenolic acids gradually increased during fermentation. Among the kinetic models adopted, first-order (R2 = 0.45–0.96) and zero-order (R2 = 0.20–0.82) equations best described the time-dependent modifications of free and bound flavonoids, respectively. On the other hand, first-order (R2 = 0.46–0.69) and second-order (R2 = 0.005–0.28) equations were best suited to explain the degradation of bound and free phenolic acids, respectively. This study shows that the modification of phenolic compounds during fermentation is compound-specific and that their rates of change may be largely dependent on their forms of existence in the fermented products.

scholarly journals KINETIC INVESTIGATION OF PROPANE DISAPPEARANCE AND PROPENE FORMATION IN PROPANE OXIDATION ON DILUTED AND LEACHED MoVTeNb CATALYST

2010 ◽  
Vol 10 (2) ◽  
pp. 172-176
Author(s):  
Restu Kartiko Widi
Keyword(s):  
Reaction Kinetics ◽  
Partial Order ◽  
Reaction Order ◽  
Propane Oxidation ◽  
Kinetic Investigation ◽  
Formation Kinetic ◽  
Kinetic Reaction ◽  
First Order ◽  
Langmuir Hinshelwood Mechanism

Reaction kinetics for the oxidation of propane over diluted-leached MoVTeNb is described. This paper is focused on the study of products selectivity profile and determination of the orders of propane disappearance and propene formation. The result shows that selective oxidation of propane to propene over this catalyst follows the Langmuir-Hinshelwood mechanism. The disappearance of propane is first order with respect to hydrocarbon and partial order (0.21) with respect to oxygen. The propene formation is first order with respect to hydrocarbon and not depending on oxygen concentration.   Keywords: propane oxidation, propane disappearance, propene formation, kinetic, reaction order

Determination of cost accounting objects, calculation and improving the calculation of product cost in agriculture

2021 ◽  
pp. 30-39
Author(s):  
Rolan Arkhipovich Alborov ◽  
Ekaterina Leonidovna Mosunova ◽  
Elena Vyacheslavovna Zakharova ◽  
Gregory Rolanovich Alborov
Keyword(s):  
Cost Accounting ◽  
Second Order ◽  
Agricultural Products ◽  
Accounting Systems ◽  
First Order ◽  
Management Accounting Systems ◽  
Order Calculation ◽  
Livestock Products ◽  
The Cost

The article deals with the problems of calculating the cost of agricultural products in crop and livestock production, associated with the methods of production accounting and management accounting systems for production facilities used in practice by agricultural organizations. Variants of definition (selection) of cost accounting objects, objects of calculation of the first order and objects of calculation of the second order are proposed. Conceptual models for the distribution of costs between the objects of the first-order calculation, the objects of the second-order calculation and the calculation of the cost of the received types of agricultural products have been developed. Using the example of the production of the main herd of dairy cattle, it is shown that the use of old methods of calculating the cost of agricultural products is not consistent, and it is recommended to use more justified methods of calculating the cost of crop and livestock products, recommended in the new editions of the relevant guidelines of the Ministry of Agriculture of the Russian Federation.

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