carbonic acids
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2021 ◽  
Vol 2 (67) ◽  
pp. 22-24
Author(s):  
N. Kamil ◽  
S. Guliyeva

The psychological and pedagogical foundations of developing education are one of the most studied issues in modern chemistry. The difficulty of learning the material taught should be at the level of the development of learners' abilities. Students' learning skills, interest in the subject and motivation should be taken into account when compiling the material. In the process of chemical education, secondary abilities are formed on the basis of abilities that include attention, imagination, memory, thinking and speech. If a chemistry teacher solves the problems of developing these and other skills of his students in a systematic and purposeful way, the average abilities can change significantly. Acmeo-combined method is one of the means of development. The development of students' acmeological thinking in the study of chemistry includes the formation of educational skills and professionalism: to put forward and formulate hypotheses of acmeo education; use existing chemical acmeology and laws to explain events; correctly formulate definitions of concepts; express your thoughts logically and consistently, get accurate results based on facts, and generalize acmeo thinking; make full use of analysis, synthesis, comparison, abstraction, concretization, generalization, systematization and integration.


2021 ◽  
Author(s):  
Maximilian Kohns ◽  
Georgia Lazarou ◽  
Spiros Kournopoulos ◽  
Esther Forte ◽  
Felipe A. Perdomo ◽  
...  

The distribution of ionic species in electrolyte systems is important in many fields of science and engineering, ranging from the study of degradation mechanisms to the design of systems for electrochemical energy storage. Often, other phenomena closely related to ionic speciation, such as ion pairing, clustering and hydrogen bonding, which are difficult to investigate experimentally, are also of interest. Here, we develop an accurate molecular approach, accounting for reactions as well as association and ion pairing, to deliver a predictive framework that helps validate experiment and guides future modelling of speciation phenomena of weak electrolytes. We extend the SAFT-VRE Mie equation of state [D. K. Eriksen et al., Mol. Phys., 2016, 114, 2724–2749] to study aqueous solutions of nitric, sulphuric, and carbonic acids, considering complete and partially dissociated models. In order to incorporate the dissociation equilibria, correlations to experimental data for the relevant thermodynamic equilibrium constants of the dissociation reactions are taken from the literature and are imposed as a boundary condition in the calculations. The models for water, the hydronium ion, and carbon dioxide are treated as transferable and are taken from our previous work. We present new molecular models for nitric acid, and the nitrate, bisulfate, sulfate, and bicarbonate anions. The resulting framework is used to predict a range of phase behaviour and solution properties of the aqueous acids over wide ranges of concentration and temperature, including the degree of dissociation, as well as the activity coefficients of the ionic species, and the activity of water and osmotic coefficient, density, and vapour pressure of the solutions. The SAFT-VRE Mie models obtained in this manner provide a means of elucidating the mechanisms of association and ion pairing in the systems studied, complementing the experimental observations reported in the literature.


2021 ◽  
Vol 7 (1) ◽  
pp. 305-310
Author(s):  
G. Osekova ◽  
Y. Tashpolotov

In the article, sodium acetate was studied and obtained from carboxylic acids from coal tar of brown coal by the method of neutralization and drying and crystallization were made. Investigated and obtained ethyl acetate from carboxylic acids from the resin of Uzgen brown coal, by the esterification method and by the low-temperature distillation method. Excess carboxylic acids and azeotropic substances were checked, repeated purification was done, and pure ethyl acetate was obtained at a temperature of 77–78 °C.


2021 ◽  
Vol 19 (2) ◽  
pp. 94-100
Author(s):  
R.H. Suleymanova ◽  
◽  
N.А. Zeynalov ◽  
О.Т. Badalova ◽  
L.N. Qulubayova ◽  
...  

The reactions of liquid-phase oxidation of aliphatic oxygen containing hydrocarbons, in particular, nonanol-4 and nonanon-4 in the presence of polyethylene-polyamine complexes (PEPA) with sorbated ions of metals with changeable valency (Co2+,Cu2+, Ni2+) were studied. It revealed that the oxidation of nonanole-4 and nonanone-4 in the presence of Cu2+ and Ni2+ ions in the analyzed system is less active while in the presence of Co2+ ions decarboxylation of acids it is practically absent and it leads mainly to formation of carbonic acids. It has been established that the character of oxidation reaction mostly depends on the properties of metals fixed on polymer matrix.


Author(s):  
Neschislyaev V.A. ◽  
Mokin P.A. ◽  
Orlova E.V. ◽  
Maslov Y.N. ◽  
Savina A.S.

Acid receiving treats indicators of specific activity of probiotics on a basis lakto-and bifidobacteria. The carbonic acids produced by them play an essential role in formation and functioning of an intestinal microbiota of a macroorganism. Acid receiving is the cultural property characterizing biochemical and substantially defining antagonistic activity of cages of production strains. The ability of bacteria to form and emit organic acids to the external environment affects their sensitivity to hydrochloric acid. It is established that more expressed activity of a kislotoobrazovaniye increases resistance of pro-biotic culture to bactericidal effect of gastric juice. Level of stability defines technological approaches to ensuring protection of cellular probiotics, including specifics of dosage forms.


2020 ◽  
Vol 22 (27) ◽  
pp. 15248-15269 ◽  
Author(s):  
Maximilian Kohns ◽  
Georgia Lazarou ◽  
Spiros Kournopoulos ◽  
Esther Forte ◽  
Felipe A. Perdomo ◽  
...  

SAFT-VRE Mie allows for elucidating association and ion pairing in weak electrolyte systems.


Author(s):  
M. O. Agafonkina ◽  
◽  
Yu. I. Kuznetsov ◽  
N. P. Andreeva ◽  
◽  
...  

2019 ◽  
Vol 16 (32) ◽  
pp. 996-1009
Author(s):  
R. N. ZHANALIYEVA ◽  
B. B. TORSYKBAYEVA ◽  
M. O. ALTYNBEKOVA ◽  
B. S. IMANGALIYEVA ◽  
A. Zh. NAZAROVA

This work is aimed at studying the reaction of nucleophilic substitution of the chlorine atom in 2-(2'-acyloxy-ethoxy) ethylchlorides with amines and a rhodanide ion and developing methods of synthesizing a 2-(2'-acyloxy-ethoxy) ethylchlorides, rhodanides, and their derivatives previously unknown in specialized literature. In the chlorohydrin molecule of diethylene glycol, there are two reaction centers that allow carrying out nucleophilic substitution reactions, as well as reactions that promote them with electrophilic reagents. The authors carried out several experiments for acylating diethylene glycol chlorohydrine with carbonic acids, reactions of nucleophilic substitution of the chlorine atom in 2-(2'-acyloxy-ethoxy) ethylchlorides with various amines as well as synthesized the chloracetoxyethyl ether of rhodane acetic acid. While studying the nucleophilic substitution of 2-(2'-acyloxy-ethoxy) ethylchlorides with the rhodanide ion, it was discovered that only the chlorine atom was replaced. The possibility of the nucleophilic substitution of the ethylene chlorohydrine was shown by the example of N-methyl and N-ethylanilines. It was discovered that the hydroxyl group of diethylene glycol could react with carbonic acids in the presences of catalysts and, therefore, encourage esterification. It has been found out that the nucleophilic substitution of the chlorine atom in 2-(2'-acyloxy-ethoxy) ethylchlorides with the rhodanide ion goes smoothly in the presence of potassium iodide acting as an activator and that the acyloxy group is unaffected. It has been discovered that the primary role in the nucleophilic substitution of alcoxyalkylhalides is played by the basicity of amines and the essence and position of substituents relative to the alcoxyl group of the haloid atom.


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