The relationship between Gibbs free energy and the intersection of the liquidi in phase diagrams of reciprocal systems

1975 ◽  
Vol 6 (4) ◽  
pp. 613-616 ◽  
Author(s):  
Mats Hillert ◽  
L. -I. Staffansson
Keyword(s):  
Free Energy ◽  
Phase Diagrams ◽  
Gibbs Free Energy ◽  
The Relationship

Chemical Thermodynamics

2021 ◽  
pp. 344-364
Author(s):  
Christopher O. Oriakhi
Keyword(s):  
Free Energy ◽  
Phase Change ◽  
Equilibrium Constant ◽  
Gibbs Free Energy ◽  
Chemical Thermodynamics ◽  
Laws Of Thermodynamics ◽  
Core Concepts ◽  
Enthalpy And Entropy Changes ◽  
Enthalpy And Entropy ◽  
The Relationship

Chemical Thermodynamics discusses the fundamental laws of thermodynamics along with their relationships to heat, work, enthalpy, entropy, and temperature. Predicting the direction of a spontaneous change and calculating the change in entropy of a reaction are core concepts. The relationship between entropy, free energy and work is covered. The Gibbs free energy is used quantitatively to predict if reactions or processes are going to be exothermic and spontaneous or endothermic under the stated conditions. Also explored are the enthalpy and entropy changes during a phase change. Finally the Gibbs free energy of a chemical reaction is related to its equilibrium constant and the temperature.

scholarly journals Thermodynamic insight into the growth of nanoscale inclusion of Al-deoxidation in Fe–O–Al melt

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hong Lei ◽  
Yuanyou Xiao ◽  
Guocheng Wang ◽  
Hongwei Zhang ◽  
Wei Jin ◽  
...  
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Gibbs Free Energy ◽  
Liquid Iron ◽  
Reaction Products ◽  
Straight Line ◽  
Nano Alumina ◽  
Increasing Temperature ◽  
The Relationship ◽  
Insight Into

Abstract Products of Al-deoxidation reaction in iron melt are the most common inclusions and play an important effect on steel performance. Understanding the thermodynamics on nano-alumina (or nano-hercynite) is very critical to explore the relationship between Al-deoxidation reaction and products growth in iron melt. In present study, a thermodynamic modeling of nano-alumina inclusions in Fe–O–Al melt has been developed. The thermodynamic results show that the Gibbs free energy changes for the formation of nano-Al2O3 and nano-FeAl2O4 decrease with the increasing size and increase with the increasing temperature. The Gibbs free energy changes for transformation of nano-Al2O3 into bulk-Al2O3 increase with the increasing size and temperature. The thermodynamic curve of nano-alumina (or nano-hercynite) and the equilibrium curve of bulk-alumina (or bulk-hercynite) obtained in this work are agree with the published experimental data of Al-deoxidation equilibria in liquid iron. In addition, the thermodynamic coexisting points about Al2O3 and FeAl2O4 in liquid iron are in a straight line and coincide with the various previous data. It suggested that these scattered experimental data maybe in the different thermodynamic state of Al-deoxidized liquid iron and the reaction products for most of the previous Al-deoxidation experiments are nano-alumina (or nano-hercynite).

High pressures and the structure of solids of geochemical and geophysical interest

1992 ◽  
Vol 56 (384) ◽  
pp. 373-383 ◽  
Author(s):  
C. H. L. Goodman
Keyword(s):  
High Pressure ◽  
Free Energy ◽  
Phase Transformations ◽  
Phase Diagrams ◽  
Gibbs Free Energy ◽  
Amorphous Materials ◽  
High Pressures ◽  
Opposite Sign ◽  
Amorphous Solids ◽  
Radius Ratio

AbstractPressures of 10 GPa and above can bring about phase transformations in many oxides, an effect of great interest to geochemists and geophysicists. We can interpret such behaviour as due to the differential compressibility of 'anion' and 'cation' leading to a progressive rise in radius ratio with pressure, and hence, on the classic crystallochemical picture, eventually to an increase in co-ordination number (though with complications which make prediction difficult). More generally, pressure affects Gibbs free energy G directly; for oxides a pressure of 5 GPa gives, very roughly, the same contribution to G as 100°C in temperature (though with opposite sign). Thus high pressure significantly affects the shape and structure of phase diagrams, showing increasingly important effects above, say, 10 GPa—but again prediction can be difficult. However these two complementary approaches to the effects of pressure, helpful though they can be conceptually, are 'crystal-based' and totally neglect another rather littleknown but potentially important effect--the formation of amorphous solids; 'polymers' and glasses. Since amorphous materials are 'non-equilibrium' they are not readily dealt with theoretically; also, since they are difficult to detect by standard crystallographic techniques, they can be overlooked experimentally. The pressure-induced formation of amorphous solids could have significant implications for both geochemistry and geophysics.

First and second laws of thermodynamics: relationship, “inconsistency”, hidden effects

2020 ◽  
pp. 63-73
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Free Energy ◽  
Internal Energy ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Entropy Of Mixing ◽  
Ideal Mixing ◽  
Laws Of Thermodynamics ◽  
Relationship Of ◽  
The Relationship

The relationship of the first and second laws of thermodynamics based on their energy nature is considered. It is noted that the processes described by the second law of thermodynamics often take place hidden within the system, which makes it difficult to detect them. Nevertheless, even with ideal mixing, an increase in the internal energy of the system occurs, numerically equal to an increase in free energy. The largest contribution to the change in the value of free energy is made by the entropy of mixing, which has energy significance. The entropy of mixing can do the job, which is confirmed in particular by osmotic processes.

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