Recent content by Silvius

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    Potentials in Pourbaix Diagrams

    Yes but why do the potentials in this case represent the potentials for the reduction of Fe^{3+} to Fe^{2+} when there is other stuff which might be contributing to the "solution" potential? Is it simply because under these conditions, those two species are the dominant species?
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    Potentials in Pourbaix Diagrams

    I see, thank you very much, Borek! How does this relate to the idea that the potential at which a horizontal line divides two oxidation states of an element is equal to the potential of the reduction half equation which relates those two species? (For example where we had Fe^{3+} (aq) and...
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    Potentials in Pourbaix Diagrams

    Hi guys, I'm having a bit of difficulty understanding Pourboix diagrams. The biggest problem at the moment is that I don't clearly understand what exactly the E° values on the y-axis are of. All the resources I've consulted haven't been especially clear about this. Sometimes they make it...
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    A Question Concerning Gravitational Potential Energy

    Thanks so much for the help =) Bearing the above in mind, how would I approach the following type of problem; "Two Earth sized/shaped bodies are separated by a distance R in deep space. The bodies are attracted to each other, and hence accelerate towards each other. How fast will each body...
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    A Question Concerning Gravitational Potential Energy

    Hmm okay. I guess it's just a bit confusing since people/questions often seem to refer simply to one of the bodies having the potential energy given by that equation (e.g., "a satellite at radius R has potential energy U = -Gm1m2/r"). Is this just an issue of expression, or am I missing...
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    A Question Concerning Gravitational Potential Energy

    Hey guys, I'm currently trying to get my head around the concept of gravitational potential energy; U_{r} = -\frac{Gm_{1}m_{2}}{r} My question concerns whether this relates to both bodies in the system individually, or together. That is, if I have two masses separated by a distance...
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    Basic Thermodynamics; Change in U at Constant Pressure

    Work is being done on the system in this case; the pressure and temperature is constant, and so a decrease in the amount of gas results in a decrease of volume of the system. That is, the surrounding constant pressure is doing work in compressing the system. Either way, I have found my error...
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    Basic Thermodynamics; Change in U at Constant Pressure

    Homework Statement What is the ΔU° at 25°C for the following reaction at constant pressure: C_{2}H_{2} (g) + 5/2O_{2} (g) \rightarrow 2CO_{2} (g) + H_{2}O (g) ΔH° = -1299.5kJ Homework Equations ΔU = Q ± W PV = nRT W = PΔV The Attempt at a Solution Since we have constant pressure, ΔH° =...
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    What Does Enthalpy of Vaporization Mean Beyond the Boiling Point?

    Ahh yes, this makes sense. Thank you!
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    What Does Enthalpy of Vaporization Mean Beyond the Boiling Point?

    I think so... And thus, that enthalpies of vaporization tend to decline with temperature represents the greater probability of molecule-escape? I suppose the intuition clash came from considering ΔH_{vap} as "the energy which needs to be added to the system" as opposed "the energy required...
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    What Does Enthalpy of Vaporization Mean Beyond the Boiling Point?

    No, but the probability is much higher, because the average kinetic energy of the water molecules is higher? Hmm.
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    What Does Enthalpy of Vaporization Mean Beyond the Boiling Point?

    Hmm, no, but I've always understood that phenomenon in a probabilistic context. That is, at any given time there is some probability that any given molecule of water possesses sufficient energy to escape into a gaseous state. Is it this "sufficient energy", then, which is represented by the...
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    What Does Enthalpy of Vaporization Mean Beyond the Boiling Point?

    Hey guys, I was just hoping to clear something up regarding enthalpies of vaporization. The idea of the heat of vaporization for a substance being "temperature dependent" is confusing me, as I had been under the impression that these quantities were only considered at the boiling point of...
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