
	Where results make sense

Topic: Gibbs free energy

Related Topics

Free energy

Thermodynamic entropy

Helmholtz function

Entropy

Free energy (disambiguation)

Internal energy

Enthalpy

Helmholtz free energy

Spontaneous process

Thermodynamic Equations

Thermodynamics

State function

Energy directory

Chemical thermodynamics

Chemical potential

In the News (Sun 22 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Gibbs Free Energy
		The balance between the contributions from the enthalpy and entropy terms to the free energy of a reaction depends on the temperature at which the reaction is run.
		As might be expected, the standard-state free energy of formation of a substance is the difference between the free energy of the substance and the free energies of its elements in their thermodynamically most stable states at 1 atm, all measurements being made under standard-state conditions.
		The contribution to the free energy of the reaction from the enthalpy term is therefore constant, but the contribution from the entropy term becomes smaller as the temperature is lowered.
	chemed.chem.purdue.edu /genchem/topicreview/bp/ch21/gibbs.php (2144 words)

	Free energy (disambiguation) Summary
		The standard free energy of formation of a pure substance is defined as the free energy change when one mole of the substance is formed from its constituent elements in their standard states.
		Free energy may be categorised as renewable energy, although most renewable energy sources would not normally be called free energy sources or sources of perpetual motion.
		Free energy is energy which may be directly utilized (and returned) by a device from the surroundings (electromagnetic free energy is sometimes referred to as radiant energy).
	www.bookrags.com /Free_energy_(disambiguation) (1018 words)

	AllRefer.com - free energy (Chemistry) - Encyclopedia
		free energy or Gibbs free energy, quantity derived from the relationships between heat and work studied in thermodynamics and used as a measure of the relative stability of a physical or chemical system, i.e., the tendency of the system to react or change.
		The reaction of hydrogen with oxygen to form water has a favorable, negative, free energy, but the reaction rate is so slow that without the presence of a catalyst it is not observable.
		G°, of various compounds; the standard free energy is the change in free energy when one mole of the compound is formed at 25°C and 1 atmospheric pressure.
	reference.allrefer.com /encyclopedia/F/freeener.html (421 words)

	University Chemistry: Gibbs Free Energy and Solution Equilibria
		Free energy relationships and other thermodynamic relationships in chemistry are based on the chemical reactions involved, in which one must keep track of the state of all components of the reacting system - pure solids, pure liquids, gases (pressure?), or solutes (concentration?).
		is -113.229 and the free energy of the dissolution reaction is +280.68 kJ/mole.
		Free energies of ionization reactions of acids and bases are related to the values of acid and base ionization constants because ionization constants refer to specific ionization equilibria.
	www.ualberta.ca /~jplambec/che/p102/p02063.htm (1378 words)

	Intute sciences - >Chemical Sciences: Thermodynamics: Gibbs Free Energy
		Useful energy, or energy available to do work, is of central interest because there is never a shortage of useful work to be done, and usually an insufficiency of useful energy to do it.
		Free energy is called Gibbs free energy and given the symbol G in honor of Josiah Willard Gibbs, a professor of chemistry at Yale University who almost singlehandedly developed both the concept and the quantitative equations which describe it.
		Free energy is a state function because it is formally defined only in terms of state functions, the state functions enthalpy and entropy, and the state variable temperature.
	www.intute.ac.uk /sciences/reference/plambeck/chem2/p02051.htm (486 words)

	Gibbs (Site not responding. Last check: 2007-09-17)
		Gibbs came up with an equation, combining both enthalpy and entropy contributions, that provided a means to describe energy content and therefore a means to evaluate the spontaneity of a reaction when that energy content changes.
		The absorption of heat energy is unfavorable and therefore must be "driven" by an increase in entropy (i.e.
		The Gibbs energy term, G, is a state function, thus values can be defined for substances at specific conditions of temperature and pressure known as the standard state.
	wine1.sb.fsu.edu /chm1046/notes/Thermody/Gibbs/Gibbs.htm (1302 words)

	Gibbs free energy - Wikipedia, the free encyclopedia
		The Gibbs free energy was developed in the 1870s by the American mathematical physicist Willard Gibbs.
		Here, in SI units, G is the Gibbs energy (joules), H is the enthalpy (joules), T is the temperature (kelvins), and S is the entropy (joules per kelvin), V is volume, P is pressure.
		The standard Gibbs free energy of formation of a compound is the change of Gibbs free energy that accompanies the formation of 1 mole of that substance from its component elements, at their standard states (the most stable form of the element at 25 degrees Celsius and 100 kilopascals).
	en.wikipedia.org /wiki/Gibbs_free_energy (2987 words)

	Helmholtz and Gibbs Free Energies
		They are internal energy, the enthalpy, the Helmholtz free energy and the Gibbs free energy.
		The amount of this spontaneous energy transfer is TS where S is the final entropy of the system.
		The Helmholtz free energy is then a measure of the amount of energy you have to put in to create a system once the spontaneous energy transfer to the sytem from the environment is accounted for.
	hyperphysics.phy-astr.gsu.edu /hbase/thermo/helmholtz.html (440 words)

	Gibbs free energy and chemical reactions
		The Gibbs free energy can also be useful in determining whether a chemical reaction is spontaneous or not.
		As with the enthalpy, the standard Gibbs free energy of formation for a chemical element in its standard state is 0.
		That is, the total change in the Gibbs free energy obtained when several chemical reactions are added together is the sum of the Gibbs free energy changes for each of the individual steps.
	www.nyu.edu /classes/tuckerman/honors.chem/lectures/lecture_18/node7.html (186 words)

	Free energy - Wikipedia, the free encyclopedia
		Gibbs free energy, the amount of thermodynamic energy in a fluid system which can be converted into non-mechanical work at constant temperature and pressure.
		Free energy (DNA) is the free energy pertaining to DNA
		Free energy suppression is the notion that corporate energy interests deliberately suppress technologies that may provide energy at very little cost.
	en.wikipedia.org /wiki/Free_energy (325 words)

	Gibbs Free Energy
		The change in free energy that occurs when a compound is formed form its elements in their most thermodynamically stable states at standard-state conditions.
		In other words, it is the difference between the free energy of a substance and the free energies of its elements in their most thermodynamically stable states at standard-state conditions.
		This shows that the free energy of a oxidation-reduction reaction is directly proportional to the cell potential of the reaction.
	library.thinkquest.org /C006669/data/Chem/thermodynamics/gibbs.html (764 words)

	Equilibrium and Energy
		For redox reactions, Gibb's energy is the electric energy, which, when properly setup in an electric cell, is the charge transferred (q in Coulomb) times the potential E (in V).
		Gibb's energy is the maximum electric energy derived from a battery.
		The application of thermodynamic data is expanded due to the introduction of the Gibb's energy, because of its link to the equilibrium constant, K.
	www.science.uwaterloo.ca /~cchieh/cact/applychem/gibbsenergy.html (1599 words)

	Gibb's Free Energy
		The Gibbs free energy derives from the second law of thermodynamics, as a special case where the temperature and pressure are constant, but that is all I will say about the second law in this, the "short answer".
		The Gibbs free energy difference is a thermodynamic function (thermodynamic function = a function that depends only on the initial and final state of some process, and not the path by which one goes from the initial to the final state.).
		The Gibbs free energy difference is defined in terms of two other thermodynamic properties, the enthalpy change denoted "dH" and the entropy change "dS".
	www.newton.dep.anl.gov /askasci/chem00/chem00752.htm (546 words)

	Binary Phase Equilibria Tutorial (Site not responding. Last check: 2007-09-17)
		For a phase, the Gibbs free energy is a function of P, T, and composition.
		Like all energies in thermodynamics, G is expressed not in absolute terms but relative to a standard state, usually the energy difference relative to the elements at 1 bar and 298.15 K. If the enthalpy of formation and third law entropy are measured, then we get G from G = H - TS.
		The intensive Gibbs free energy of a phase is also, in general, a function of composition.
	expet.gps.caltech.edu /~asimow/tutorial1.html (2399 words)

	Binary Phase Equilibria Tutorial
		For a phase, the Gibbs free energy is a function of P, T, and composition.
		Like all energies in thermodynamics, G is expressed not in absolute terms but relative to a standard state, usually the energy difference relative to the elements at 1 bar and 298.15 K. If the enthalpy of formation and third law entropy are measured, then we get G from G = H - TS.
		The intensive Gibbs free energy of a phase is also, in general, a function of composition.
	www.gps.caltech.edu /~asimow/tutorial1.html (2399 words)

	Gibbs (free energy) questions
		The "FORWARD" free energy reported is ALWAYS the value corresponding to the change (0->1), regardless of the actual direction in which the simulation was performed.
		Setting IDWIDE = 1 changes the trajectory, and hence the computed free energy (although values calculated from any trajectory will be the same in the limit of infinite sampling, in the finite sampling domain, they will differ).
		The "CORC" value is, in principal, the contribution from the constrained bonds to the total free energy.
	amber.scripps.edu /Questions/gibbs.html (1582 words)

	Free energy: the Gibbs function
		The free energy of a gas depends on its pressure; the higher the pressure, the higher the free energy.
		Thus the free expansion of a gas, a spontaneous process, is accompanied by a fall in the free energy.
		The existence of sharp melting and boiling points reflects the differing temperature dependancies of the free energies of the solid, liquid, and vapor phases of a pure substance, which are in turn reflect their differing entropies.
	www.chem1.com /acad/webtext/thermeq/TE4.html (3213 words)

	Gibbs free energy - HighBeam Encyclopedia (Site not responding. Last check: 2007-09-17)
		The Gibbs Free Energy formula maps out how thermodynamically instable emulsions can be kinetically stable enough to put great products on a shelf.(Chemical Reaction)
		The use of Gibbs energy diagrams in the teaching of organic chemistry.
		Gibbs Symposium 2003 to honor "One of the World's Greatest Scientists" at Yale.
	www.encyclopedia.com /doc/1E1-X-Gibbsfre.html (470 words)

	Gibbs free energy - Encyclopedia of Earth
		Gibbs free energy is a measure of the maximum available work that can be derived from any system under conditions of constant temperature (T) and pressure (P).
		For chemical changes, tabulated standard free energy values can be used to predict the direction and energy yield of a particular reaction.
		Willard Gibbs (1839-1903) first defined the free energy function that bears his name in the landmark theoretical papers of 1876 and 1878 that have led most authorities to rank among America's greatest native-born scientist.
	www.eoearth.org /article/Gibbs_free_energy (378 words)

	Free Energy
		The isothermal-isobaric ensemble (NPT), with a constant number of particles, pressure, and temperature, is used to obtain the Gibbs free energy.
		For relatively rigid systems with few degrees of freedom, the free energy may be calculated by direct calculation of the partition function.
		The overal free energy change is then obtained by summing the change from each of the steps.
	www.biochem.vt.edu /modeling/deltaG.html (1445 words)

	Chapter 10 Notes
		We will use the same trick later in the chapter to talk about the standard Gibbs energy (or enthalpy or entropy) for reactions in which an electron is transferred from one species to another, since this always involves the formation or consumption of two ions.
		A molar Gibbs free energy is the amount of free energy it takes to convert one mole of a substance from one form or state to another.
		The other part of the proportionality comes from the fact that the Gibbs free energy is based on the amount of the chemical being oxidized or reduced while the voltage is based on the number of electrons that flow during the oxidation/reduction reaction.
	www.public.asu.edu /~laserweb/woodbury/classes/chm341/lecture_set10/lecture10.html (3667 words)

	PinkMonkey.com - Chemistry Study Guide -10.5 Gibbs Free Energy
		Gibbs Free Energy is a criterion for spontaneity and takes into account the entropy change of the surroundings.
		is defined as the change in standard free energies when 1 mole of a substance is prepared from its constituent elements.
		C and 1 atm is assigned a standard free energy of zero.
	www.pinkmonkey.com /studyguides/subjects/chem/chap10/c1010501.asp (176 words)

	Gibbs free energy
		Gibbs free energy is the energy liberated or absorbed in a reversible process at constant pressure and constant temperature.
		It is sometimes called Gibbs energy and, in older literature, simply "free energy."
		Changes in Gibbs free energy, delta G, are useful in indicating the conditions under which a chemical reaction will occur.
	www.daviddarling.info /encyclopedia/G/Gibbs_free_energy.html (155 words)

Try your search on: Qwika (all wikis)