Thermodynamics of carbon dioxide and carbonic acid: (a) the standard enthalpies of solution of Na2CO3(s), NaHCO3(s), and CO2(g) in water at 298.15 K; (b) the standard enthalpies of formation, standard Gibbs energies of formation, and standard entropies of CO2(aq), HCO3−(aq), CO32−(aq), NaHCO3(s), Na2CO3(s), Na2CO3·H2O(s), and Na2CO3·10H2O(s)

1978 ◽  
Vol 10 (12) ◽  
pp. 1113-1136 ◽  
Author(s):  
Robert L Berg ◽  
Cecil E Vanderzee
Keyword(s):  
Carbon Dioxide ◽  
Carbonic Acid ◽  
Enthalpies Of Formation ◽  
Enthalpies Of Solution ◽  
Gibbs Energies ◽  
Standard Enthalpies Of Formation

Calorimetric study of the digestion of gibbsite, Al(OH)3(cr), and thermodynamics of aqueous aluminate ion, Al(OH)4−(aq)

1991 ◽  
Vol 69 (11) ◽  
pp. 1685-1690 ◽  
Author(s):  
Qiyuan Chen ◽  
Yuming Xu ◽  
Loren G. Hepler
Keyword(s):  
Thermodynamic Properties ◽  
Aqueous Sodium Hydroxide ◽  
Sodium Aluminate ◽  
Heat Capacities ◽  
Enthalpies Of Formation ◽  
Calorimetric Study ◽  
Enthalpies Of Solution ◽  
Calorimetric Measurements ◽  
Wide Range ◽  
Standard Enthalpies Of Formation

We have made calorimetric measurements of the enthalpies of solution of gibbsite, Al(OH)3(cr), in aqueous sodium hydroxide solutions at five temperatures from 100 to 150 °C. Results of these measurements have been used to obtain the standard enthalpies of formation of Na+(aq) + Al(OH)4−(aq) at the experimental temperatures. These results have also led to values of ΔCp0 for the reaction represented concisely by Al(OH)3(cr) + OH−(aq) = Al(OH)4−(aq), from which we have obtained standard state partial molar heat capacities of Na+(aq) + Al(OH)4−(aq). Combination of our results with those from earlier investigations has permitted calculation of thermodynamic properties of Na+(aq) + Al(OH)4−(aq) over a wide range of temperature and thence some generalizations about the usefulness of various equations for representing or predicting these thermodynamic properties. Key words: gibbsite, enthalpy of solution; sodium aluminate (aqueous), thermodynamic properties; heat capacities, Na+(aq) + Al(OH)4−(aq).

scholarly journals Enthalpies of formation of lanthanide oxyapatite phases

2001 ◽  
Vol 16 (10) ◽  
pp. 2780-2783 ◽  
Author(s):  
A. S. Risbud ◽  
K. B. Helean ◽  
M. C. Wilding ◽  
P. Lu ◽  
A. Navrotsky
Keyword(s):  
Structural Formula ◽  
Solution Calorimetry ◽  
Enthalpies Of Formation ◽  
Enthalpies Of Solution ◽  
Thermodynamic Cycles ◽  
Oxide Melt ◽  
Formation Enthalpies ◽  
High Temperature Oxide ◽  
Standard Enthalpies Of Formation ◽  
Temperature Oxide

A family of lanthanide silicates adopts an oxyapatitelike structure with structural formula Ln9.33 0.67(SiO4)6O2 (Ln = La, Sm, Nd, Gd,   = vacancy). The enthalpies of solution, ΔHS, for these materials and their corresponding binary oxides were determined by high-temperature oxide melt solution calorimetry using molten 2PbO B2O3 at 1078 K. These data were used to complete thermodynamic cycles to calculate enthalpies of formation from the oxides, ΔH0 f-oxides (kJ/mol): La9.33 0.67(SiO4)6O2 = 776.3 ± 17.9, Nd9.33 0.67(SiO4)6O2 = 760.4 ± 31.9, Sm9.33 0.67(SiO4)6O2 = 590.3 ± 18.6, and Gd9.33 0.67(SiO4)6O2 = 446.9 ± 21.9. Reference data were used to calculate the standard enthalpies of formation from the elements, ΔH0 f (kJ/mol): La9.33 0.67(SiO4)6O2 = 14611.0 ± 19.4, Nd9.33 0.67(SiO4)6O2 = 14661.5 ± 32.2, Sm9.33 0.67(SiO4)6O2 = -14561.7 ±; 20.8, and Gd9.33 0.67(SiO4)6O2 = -14402.7 ± 28.2. The formation enthalpies become more endothermic as the ionic radius of the lanthanide ion decreases.

Thermochemical study of adducts of methylurea with zinc, cadmium, and mercury halides

1982 ◽  
Vol 60 (16) ◽  
pp. 2132-2136 ◽  
Author(s):  
Claudio Airoldi ◽  
Aécio P. Chagas ◽  
Francisco P. Assunção
Keyword(s):  
Standard Enthalpy ◽  
Enthalpies Of Formation ◽  
Enthalpy Of Sublimation ◽  
Thermochemical Study ◽  
Enthalpies Of Solution ◽  
Metal Halides ◽  
Enthalpies Of Dissolution ◽  
Zinc Cadmium ◽  
Standard Enthalpies Of Formation

The adducts Zn(mu)2X2 (X = Cl, Br), M(mu)X, (M = Cd, Hg and X = Cl, Br) have been characterized. The CO and NH stretching frequencies indicate that methylurea (mu) is bound to metals through oxygen. Enthalpies of dissolution of the adducts in ethanol or methanol have been measured calorimetrically. Combination with the enthalpies of solution of metal halides and ligand in the same solvents at 298.15 K yielded the standard enthalpy [Formula: see text] for the reaction: MX,(s) + nmu(s) → M(mu)nX2, (s): Zn(mu)2Cl2, (−36.27±0.51); Zn(mu)2Br2, (−37.52±0.97); Cd(mu)Cl2, (−22.78±0.26); Cd(mu)Br2, (−9.58±0.26); Hg(mu)Cl2, (−13.91±0.41);and Hg(mu)Br2,(−13.29±0.48). The standard enthalpies of formation of the adducts in the same sequence as above, [Formula: see text] (s, 298.15 K): −1024, −938, −701, −612, −524, and −470 kJ mol−1, were determined from these values, the standard enthalpy of the ligand (−285 ± 15 kJ mol−1) being obtained via combustion calorimetry, and literature values of the standard enthalpies of metal halides being used. With the determination of the standard enthalpy of sublimation of the ligand (78.2 kJ mol−1) it was possible to determine the standard enthalpies of the reactions MX2(g) + nmu(g) → M(mu)X2 (s) and M(mu)nX2 (s) → MX2 (s) + nmu(g). The enthalpies of metal–oxygen bonds were also estimated.

Antistaphylococcal activity of carbonic acid extract of hops

2018 ◽  
Vol 22 (2) ◽  
pp. 297-300
Author(s):  
V.V. Nevmerzhitsky ◽  
V.Yu. Ivannik ◽  
V.V. Kazmirchuk ◽  
T.N. Moiseenko ◽  
T.A. Volkov ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Antimicrobial Agents ◽  
Carbonic Acid ◽  
Inflammatory Diseases ◽  
Acquired Resistance ◽  
Biologically Active ◽  
Antibacterial Drugs ◽  
Antistaphylococcal Activity ◽  
Prevention And Treatment ◽  
Main Disadvantage

The fight against staphylococcal infection, increasing the effectiveness of methods of prevention and treatment of diseases of staphylococcal etiology is of interest to scientists and practitioners, both in Ukraine and around the world. The urgency of this problem is growing rapidly, as there is a tendency to increase the resistance of not only staphylococci, but also other gram-positive bacteria. The spread of methicillin-resistant staphylococci restricts the choice of antibiotics for the treatment of diseases of staphylococcal etiology. Staphylococcus aureus is the most common and dangerous type, which is one of the main factors of purulent-inflammatory lesions of the skin and mucous membranes. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. As a result of mutations, pathogenic staphylococci acquired resistance to antibacterial drugs. The main disadvantage of modern antibiotics is their non-selectivity. One of the unique and promising medicinal plants, which contains a rich complex of biologically active substances (BAS), is common hops (Humulus lupulus L.). The complex of BAS (flavonoids, hormones, vitamins, bitter, phenolic compounds, essential oils) causes anti-inflammatory, bactericidal, hyposensitizing and analgesic action of hops. The purpose of this work is to determine the antistaphylococcal activity of the carbon dioxide extract of hops and to justify the development on its basis of new antimicrobial agents for the prevention and treatment of infectious and purulent-inflammatory diseases. The following methods were used: microbiological (method of diffusion into agar (well method)) and mathematical and statistical. The high antimicrobial activity of the carbon dioxide extract of hops has been established for museum test strains of the genus Staphylococcus. The results of the studies testify to the prospects of further study of the bactericidal properties of the extract of hops carbon dioxide with the aim of creating effective antimicrobial agents on its basis for the prevention and treatment of infectious and purulent-inflammatory diseases of staphylococcal etiology.

Application of Disk Aerators to Recarbonation of Alkaline Wastewater from Wet Gasification of Carbide

1991 ◽  
Vol 24 (7) ◽  
pp. 277-284 ◽  
Author(s):  
E. Gomólka ◽  
B. Gomólka
Keyword(s):  
Carbon Dioxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
Flue Gas ◽  
Carbonic Acid ◽  
Low Cost ◽  
Flue Gases ◽  
Carbon Dioxide Content ◽  
Patent Claim ◽  
Phase Dispersion

Whenever possible, neutralization of alkaline wastewater should involve low-cost acid. It is conventional to make use of carbonic acid produced via the reaction of carbon dioxide (contained in flue gases) with water according to the following equation: Carbon dioxide content in the flue gas stream varies from 10% to 15%. The flue gas stream may either be passed to the wastewater contained in the recarbonizers, or. enter the scrubbers (which are continually sprayed with wastewater) from the bottom in oountercurrent. The reactors, in which recarbonation occurs, have the ability to expand the contact surface between gaseous and liquid phase. This can be achieved by gas phase dispersion in the liquid phase (bubbling), by liquid phase dispersion in the gas phase (spraying), or by bubbling and spraying, and mixing. These concurrent operations are carried out during motion of the disk aerator (which is a patent claim). The authors describe the functioning of the disk aerator, the composition of the wastewater produced during wet gasification of carbide, the chemistry of recarbonation and decarbonation, and the concept of applying the disk aerator so as to make the wastewater fit for reuse (after suitable neutralization) as feeding water in acetylene generators.

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