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<blockquote data-quote="Phil Graham" data-source="post: 48560" data-attributes="member: 430">Re: Water damage... causesKinetics, by the very definition of the word, does not have any place in a Keq calculation. The core of thermodynamics is our ability to calculate changes in state inifinitesimally for the reversible case, and then use it to say something useful about the theoretical equilibrium of the real, irreversible system.Of course in real systems, kinetic considerations are often dominant, and the thermodynamic equations of equilibrium stability not predictive of the actual concentrations. Those real values, however, are not equilibria. Not that anyone here is going to conflate the two approaches <img src="https://cdn.jsdelivr.net/joypixels/assets/8.0/png/unicode/64/1f642.png" class="smilie smilie--emoji" loading="lazy" width="64" height="64" alt=":)" title="Smile&nbsp; &nbsp; :)"&nbsp; data-smilie="1"data-shortname=":)" />Also, especially in the gas phase, those insignificant product amounts really can matter greatly. There are many important &quot;insignificant&quot; reaction in gas phase chemistry, such as the water gas shift reaction.Certainly a voltage influences the situation, as calculated by the Nerst equation for equilibrium. My point is that your assumption that galvanic couples requires dissimilar metals is not necessarily the case. Two coupons of the same metal in contact with solutions of different ionic makeup, including the case where dissolved oxygen modifies the ionic content, can produce a galvanic couple when shorted together, assuming a suitable ion bridge between the coupon solutions. The net reaction current can be estimated from mixed potential theory.</blockquote>

[QUOTE="Phil Graham, post: 48560, member: 430"] Re: Water damage... causes Kinetics, by the very definition of the word, does not have any place in a Keq calculation. The core of thermodynamics is our ability to calculate changes in state inifinitesimally for the reversible case, and then use it to say something useful about the theoretical equilibrium of the real, irreversible system.Of course in real systems, kinetic considerations are often dominant, and the thermodynamic equations of equilibrium stability not predictive of the actual concentrations. Those real values, however, are not equilibria. Not that anyone here is going to conflate the two approaches :)Also, especially in the gas phase, those insignificant product amounts really can matter greatly. There are many important "insignificant" reaction in gas phase chemistry, such as the water gas shift reaction.Certainly a voltage influences the situation, as calculated by the Nerst equation for equilibrium. My point is that your assumption that galvanic couples requires dissimilar metals is not necessarily the case. Two coupons of the same metal in contact with solutions of different ionic makeup, including the case where dissolved oxygen modifies the ionic content, can produce a galvanic couple when shorted together, assuming a suitable ion bridge between the coupon solutions. The net reaction current can be estimated from mixed potential theory. [/QUOTE]

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