https://wikimd.com/index.php?action=history&feed=atom&title=Activity_coefficient 2026-04-04T04:39:10Z Revision history for this page on the wiki MediaWiki 1.44.2 https://wikimd.com/index.php?title=Activity_coefficient&diff=6303880&oldid=prev 2025-02-16T22:13:55Z

<p>CSV import</p> <table style="background-color: #fff; color: #202122;" data-mw="interface"> <col class="diff-marker" /> <col class="diff-content" /> <col class="diff-marker" /> <col class="diff-content" /> <tr class="diff-title" lang="en"> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">← Older revision</td> <td colspan="2" style="background-color: #fff; color: #202122; text-align: center;">Revision as of 22:13, 16 February 2025</td> </tr><tr><td colspan="2" class="diff-lineno" id="mw-diff-left-l43">Line 43:</td> <td colspan="2" class="diff-lineno">Line 43:</td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Thermodynamics]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Thermodynamics]]</div></td></tr> <tr><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Physical chemistry]]</div></td><td class="diff-marker"></td><td style="background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;"><div>[[Category:Physical chemistry]]</div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;"></ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">== Activity Coefficient ==</ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">&lt;gallery&gt;</ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">File:UNIQUACRegressionChloroformMethanol.png</ins></div></td></tr> <tr><td colspan="2" class="diff-side-deleted"></td><td class="diff-marker" data-marker="+"></td><td style="color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;"><div><ins style="font-weight: bold; text-decoration: none;">&lt;/gallery&gt;</ins></div></td></tr> </table>

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<p>CSV import</p> <p><b>New page</b></p><div>{{Short description|A measure of deviation from ideal behavior in a mixture}}<br /> <br /> == Activity coefficient ==<br /> The &#039;&#039;&#039;activity coefficient&#039;&#039;&#039; is a factor used in thermodynamics to account for deviations from ideal behavior in a mixture of chemical substances. In an ideal solution, the interactions between molecules are the same as those in the pure components, and the activity coefficient is equal to one. However, in real solutions, interactions can differ, leading to activity coefficients that deviate from unity.<br /> <br /> == Definition ==<br /> In a mixture, the activity \( a_i \) of a component \( i \) is related to its concentration \( c_i \) by the equation:<br /> <br /> \[<br /> a_i = \gamma_i c_i<br /> \]<br /> <br /> where \( \gamma_i \) is the activity coefficient of component \( i \). The activity coefficient quantifies the non-ideal behavior of the solution.<br /> <br /> == Importance ==<br /> Activity coefficients are crucial in [[chemical thermodynamics]] for calculating the [[chemical potential]] of a species in a mixture. They are used in the [[Gibbs free energy]] calculations and are essential for understanding [[phase equilibria]], [[reaction equilibria]], and [[electrolyte solutions]].<br /> <br /> == Models for Activity Coefficients ==<br /> Several models exist to estimate activity coefficients, including:<br /> <br /> * [[Debye–Hückel theory]]: Used for dilute electrolyte solutions.<br /> * [[UNIQUAC]] (Universal Quasi-Chemical): A model for predicting activity coefficients in non-electrolyte solutions.<br /> * [[NRTL]] (Non-Random Two-Liquid): A model that accounts for non-randomness in liquid mixtures.<br /> <br /> == Applications ==<br /> Activity coefficients are used in various fields such as:<br /> <br /> * [[Chemical engineering]]: For designing separation processes like [[distillation]] and [[extraction]].<br /> * [[Environmental science]]: To model the behavior of pollutants in natural waters.<br /> * [[Pharmaceuticals]]: In the formulation of drugs to ensure proper solubility and stability.<br /> <br /> == Related pages ==<br /> * [[Chemical potential]]<br /> * [[Gibbs free energy]]<br /> * [[Phase equilibria]]<br /> * [[Electrolyte solution]]<br /> <br /> == Gallery ==<br /> &lt;gallery&gt;<br /> File:UNIQUACRegressionChloroformMethanol.png|Graph showing UNIQUAC regression for chloroform and methanol.<br /> &lt;/gallery&gt;<br /> <br /> [[Category:Thermodynamics]]<br /> [[Category:Physical chemistry]]</div>

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