Gibbs free energy - Revision history

Nnjm2 at 02:25, 30 November 2013

2013-11-30T02:25:22Z

130095187 at 12:18, 29 November 2013

2013-11-29T12:18:44Z

130095187 at 12:17, 29 November 2013

2013-11-29T12:17:02Z

130095187 at 12:15, 29 November 2013

2013-11-29T12:15:28Z

Nnjm2 at 03:02, 29 November 2013

2013-11-29T03:02:57Z

← Older revision		Revision as of 03:02, 29 November 2013
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	1800s, Josiah Willard Gibbs, (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:		1800s, [[Josiah Willard Gibbs\|Josiah Willard Gibbs]], (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:
	<blockquote>'''Entropy can never decrease, only increase for a reaction to take place.''' </blockquote>		<blockquote>'''Entropy can never decrease, only increase for a reaction to take place.''' </blockquote>
	in order to measure the amount of free enerfy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>		in order to measure the amount of free enerfy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>

	~~<u>'''~~Why doesn't free energy = enthalpy - entropy?~~'''</u>~~		=== Why doesn't free energy = enthalpy - entropy? ===

	~~<u>'''~~Reasoning behind Gibbs equation~~ '''</u><br>~~The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref> could be:		==== Reasoning behind Gibbs equation ====
	<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref></blockquote>
			The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref> could be: ====
			<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	'''<u>~~Application~~</u>'''		==== '''<u></u>'''Application'''<u></u>''' ====

	~~We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" ~~<~~ref~~>~~Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.~~</~~ref~~> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''~~dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.~~

	<br>		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

	~~<references />~~		=== References ===

	<references />		<references /><br>

130291022 at 16:52, 28 November 2013

2013-11-28T16:52:24Z

← Older revision		Revision as of 16:52, 28 November 2013
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	<u>'''Why doesn't free energy = enthalpy - entropy?'''</u>		<u>'''Why doesn't free energy = enthalpy - entropy?'''</u>

	<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref> could be:		<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref> could be:
	<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref></blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref></blockquote>
	'''<u>Application</u>'''		'''<u>Application</u>'''

	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

	<br>		<br>

130291022 at 16:51, 28 November 2013

2013-11-28T16:51:54Z

← Older revision		Revision as of 16:51, 28 November 2013
Line 5:		Line 5:
	<u>'''Why doesn't free energy = enthalpy - entropy?'''</u>		<u>'''Why doesn't free energy = enthalpy - entropy?'''</u>

	<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function" could be:		<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref> could be:
	<blockquote>'''X= U - S''' (where X = Function, U = Enthalpy, S = Entropy) </blockquote>		<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref></blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' (where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function)</blockquote>		<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref></blockquote>
	'''<u>Application</u>'''		'''<u>Application</u>'''

	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

	<br>		<br>

130291022 at 16:49, 28 November 2013

2013-11-28T16:49:54Z

← Older revision		Revision as of 16:49, 28 November 2013
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	in order to measure the amount of free enerfy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>		in order to measure the amount of free enerfy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>

	~~<u</u>~~<u>'''Why doesn't free energy = enthalpy - entropy?'''</u>		<u>'''Why doesn't free energy = enthalpy - entropy?'''</u>

	<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." As a consequence the one equation proposed for this "unknown energy function" could be:		<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley & Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function" could be:
	<blockquote>'''X= U - S''' (where X = Function, U = Enthalpy, S = Entropy) </blockquote>		<blockquote>'''X= U - S''' (where X = Function, U = Enthalpy, S = Entropy) </blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
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	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

			<br>

			<references />

	<references />		<references />

130291022 at 16:45, 28 November 2013

2013-11-28T16:45:35Z

← Older revision		Revision as of 16:45, 28 November 2013
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	1800s, Josiah Willard Gibbs, (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:		1800s, Josiah Willard Gibbs, (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:
	<blockquote>		<blockquote>'''Entropy can never decrease, only increase for a reaction to take place.''' </blockquote>
	'''Entropy can never decrease, only increase for a reaction to take place.'''		in order to measure the amount of free enerfy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>
	</blockquote>
	in order to measure the amount of free enerfy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>		<u</u><u>'''Why doesn't free energy = enthalpy - entropy?'''</u>
	<~~blockquote~~</~~blockquote~~><u>'''Why doesn't free energy = enthalpy - entropy?'''</u>

	<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." As a consequence the one equation proposed for this "unknown energy function" could be:		<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." As a consequence the one equation proposed for this "unknown energy function" could be:
Line 10:		Line 9:
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' (where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function)</blockquote>		<blockquote>'''dG = dH - dTS''' (where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function)</blockquote>
	'''<u>Application</u>'''		'''<u>Application</u>'''

			We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.



	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		<references />

130291022 at 16:44, 28 November 2013

2013-11-28T16:44:47Z

← Older revision		Revision as of 16:44, 28 November 2013
Line 1:		Line 1:
	1800s, Josiah Willard Gibbs, (1839-1903) submitted scientific papers which ~~contained mostly observations on systems at equilibrium. To do so Gibbs~~ mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:		1800s, Josiah Willard Gibbs, (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:
	<blockquote>'''~~entropy~~ can never decrease, only increase for a reaction to take place.''' </blockquote>		<blockquote>
	<u>'''Why doesn't free energy = enthalpy - entropy?'''</u>		'''Entropy can never decrease, only increase for a reaction to take place.'''
			</blockquote>
			in order to measure the amount of free enerfy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>
			<blockquote</blockquote><u>'''Why doesn't free energy = enthalpy - entropy?'''</u>

	<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." As a consequence the one equation proposed for this "unknown energy function" could be:		<u>'''Reasoning behind Gibbs equation '''</u><br>The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." As a consequence the one equation proposed for this "unknown energy function" could be:
	<blockquote>'''X= U - S''' (where X = Function, U = Enthalpy, S = Entropy) </blockquote>		<blockquote>'''X= U - S''' (where X = Function, U = Enthalpy, S = Entropy) </blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following ~~potential~~ equation:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''G = H - TS''' (where G = ~~Function~~, H = Enthalpy, S = Entropy, T = Temperature) </blockquote>		<blockquote>'''dG = dH - dTS''' (where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function)</blockquote>
			'''<u>Application</u>'''

			We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

← Older revision		Revision as of 02:25, 30 November 2013
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	1800s, [[Josiah Willard Gibbs\|Josiah Willard Gibbs]], (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:		1800s, [[Josiah Willard Gibbs\|Josiah Willard Gibbs]], (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:
	<blockquote>'''Entropy can never decrease, only increase for a reaction to take place.''' </blockquote>		<blockquote>'''Entropy can never decrease, only increase for a reaction to take place.''' </blockquote>
	in order to measure the amount of free energy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>		in order to measure the amount of free energy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>

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	==== Reasoning behind Gibbs equation ====		==== Reasoning behind Gibbs equation ====

	The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley ~~&amp;amp;amp;amp;amp;amp;amp;~~ Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley ~~&amp;amp;amp;amp;amp;amp;~~ Sons, Inc.. p84-90.</ref> could be: ====		The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley and Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley and Sons, Inc.. p84-90.</ref> could be: ====
	<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley ~~&amp;amp;amp;amp;amp;amp;~~ Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley and Sons, Inc.. p84-90.</ref></blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley ~~&amp;amp;amp;amp;amp;amp;~~ Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley and Sons, Inc.. p84-90.</ref></blockquote>
	==== '''<u></u>'''Application'''<u></u>''' ====		==== '''<u></u>'''Application'''<u></u>''' ====

	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley ~~&amp;amp;amp;amp;amp;amp;~~ Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley and Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

	=== References ===		=== References ===

	<references /~~><br~~>		<references />

← Older revision		Revision as of 12:18, 29 November 2013
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	in order to measure the amount of free energy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>		in order to measure the amount of free energy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>

	According to the second law of thermodynamics, a chemical reaction can only proceed spontaneously if there is a net increase in disorder I the universe. An increase in disorder of the universe can be expressed most conveniently in terms of a quantity called the free energy, G of a system. The value of G is of interest only when a system undergoes a change, such as a reaction, in such a case the value of delta G is critical. Energetically favourable reactions are those that decrease free energy and have a negative delta G, these reactions  add more to disorder to the universe.<ref name="null">Alberts et al.Molecular Biology of the Cell,(2008)5th Ed.</ref>		According to the second law of thermodynamics, a chemical reaction can only proceed spontaneously if there is a net increase in disorder I the universe. An increase in disorder of the universe can be expressed most conveniently in terms of a quantity called the free energy, G of a system. The value of G is of interest only when a system undergoes a change, such as a reaction, in such a case the value of delta G is critical. Energetically favourable reactions are those that decrease free energy and have a negative delta G, these reactions  add more to disorder to the universe.<ref name="null">Alberts et al.Molecular Biology of the Cell,(2008) 5th Ed. Page 75</ref>

	=== Why doesn't free energy = enthalpy - entropy? ===		=== Why doesn't free energy = enthalpy - entropy? ===
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	==== Reasoning behind Gibbs equation ====		==== Reasoning behind Gibbs equation ====

	The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> could be: ====		The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> could be: ====
	<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	==== '''<u></u>'''Application'''<u></u>''' ====		==== '''<u></u>'''Application'''<u></u>''' ====

	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

	=== References ===		=== References ===

	<references /><br>		<references /><br>

← Older revision		Revision as of 12:17, 29 November 2013
Line 3:		Line 3:
	in order to measure the amount of free energy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>		in order to measure the amount of free energy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>

	According to the second law of thermodynamics, a chemical reaction can only proceed spontaneously if there is a net increase in disorder I the universe. An increase in disorder of the universe can be expressed most conveniently in terms of a quantity called the free energy, G of a system. The value of G is of interest only when a system undergoes a change, such as a reaction, in such a case the value of delta G is critical. Energetically favourable reactions are those that decrease free energy and have a negative delta G, these reactions  add more to disorder to the universe.<ref>Molecular Biology of the Cell,(2008) 5th Ed~~. Alberts et al~~.</ref>		According to the second law of thermodynamics, a chemical reaction can only proceed spontaneously if there is a net increase in disorder I the universe. An increase in disorder of the universe can be expressed most conveniently in terms of a quantity called the free energy, G of a system. The value of G is of interest only when a system undergoes a change, such as a reaction, in such a case the value of delta G is critical. Energetically favourable reactions are those that decrease free energy and have a negative delta G, these reactions  add more to disorder to the universe.<ref name="null">Alberts et al.Molecular Biology of the Cell,(2008)5th Ed.</ref>

	=== Why doesn't free energy = enthalpy - entropy? ===		=== Why doesn't free energy = enthalpy - entropy? ===
Line 9:		Line 9:
	==== Reasoning behind Gibbs equation ====		==== Reasoning behind Gibbs equation ====

	The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> could be: ====		The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> could be: ====
	<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	==== '''<u></u>'''Application'''<u></u>''' ====		==== '''<u></u>'''Application'''<u></u>''' ====

	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

	=== References ===		=== References ===

	<references /><br>		<references /><br>

← Older revision		Revision as of 12:15, 29 November 2013
Line 1:		Line 1:
	1800s, [[Josiah Willard Gibbs\|Josiah Willard Gibbs]], (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:		1800s, [[Josiah Willard Gibbs\|Josiah Willard Gibbs]], (1839-1903) submitted scientific papers which mathematically combined both enthalpy and entropy (the measure of energy release and disorder in a system respectively) that also incorporates the second law of thermodynamics:
	<blockquote>'''Entropy can never decrease, only increase for a reaction to take place.''' </blockquote>		<blockquote>'''Entropy can never decrease, only increase for a reaction to take place.''' </blockquote>
	in order to measure the amount of free ~~enerfy~~ present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>		in order to measure the amount of free energy present within any given system.<ref name="Hmolpedia">Sadi, Carnot. (2013). Willard Gibbs. Available: http://www.eoht.info/page/Willard+Gibbs. Last accessed 28th Nov 2013.</ref>

			According to the second law of thermodynamics, a chemical reaction can only proceed spontaneously if there is a net increase in disorder I the universe. An increase in disorder of the universe can be expressed most conveniently in terms of a quantity called the free energy, G of a system. The value of G is of interest only when a system undergoes a change, such as a reaction, in such a case the value of delta G is critical. Energetically favourable reactions are those that decrease free energy and have a negative delta G, these reactions  add more to disorder to the universe.<ref>Molecular Biology of the Cell,(2008) 5th Ed. Alberts et al.</ref>

	=== Why doesn't free energy = enthalpy - entropy? ===		=== Why doesn't free energy = enthalpy - entropy? ===
Line 7:		Line 9:
	==== Reasoning behind Gibbs equation ====		==== Reasoning behind Gibbs equation ====

	The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref> could be: ====		The signs for enthalpy and entropy must be opposites to each other, "because one function tends to a maximum and the other tends to a minimum." <ref name="Concise Physical Chemistry">Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp;amp; Sons, Inc.. p84-90.</ref>As a consequence the one equation proposed for this "unknown energy function"<ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> could be: ====
	<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''X= U - S''' </blockquote><blockquote>(where X = Function, U = Enthalpy, S = Entropy) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:		Although this must be carried out under standard conditions, so U must be substituted for an H to demonstrate a constant pressure. (of 1atm) In addition to this, the units are wrong in our current equation; as we know, enthalpy is measure in joules ('''J''') of energy, entropy on the other hand is measured in joules per kelvin. ('''J K<sup>-1</sup>''') Thus, we must also multiply entropy ('''S''') by temperature in Kelvin. ('''T''') Giving us the following equation when delta symbols are incorporate to represent that this function is for free energy changes:
	<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>		<blockquote>'''dG = dH - dTS''' </blockquote><blockquote>(where G = Free energy, H = Enthalpy, S = Entropy, T = Temperature, d = Change in associated function) <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref></blockquote>
	==== '''<u></u>'''Application'''<u></u>''' ====		==== '''<u></u>'''Application'''<u></u>''' ====

	We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.		We can now determine each individual component of this equation, enthalpy change being determined via "calorimetric measurment" <ref>Donald W. Rogers (2010). Concise Physical Chemistry. Hoboken: John Wiley &amp;amp;amp;amp; Sons, Inc.. p84-90.</ref> to give us our value for '''dH; '''entropy can then be found if '''dG''' and temperature are known, the opposite can be said for determining '''dG''' itself with '''dS '''being our known value instead. For a reaction to be possible, it has been stated that the entropy of the universe is always increased. Consequently for a reaction to take place, '''dG '''must always be negative, with '''dS''' in the the equation for free energy exceeding that of the enthalpy change '''dH'''.

	=== References ===		=== References ===

	<references /><br>		<references /><br>