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| Ask the Oracle! | |
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| Tweet Topic Started: Feb 10 2008, 08:29 AM (1,131 Views) | |
| Kururugi | Feb 29 2008, 03:25 PM Post #31 |
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I am the very disease you pretend to be
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Why won't I become a billionaire? |
| If you don't want an enemy, don't fuck with my life. | |
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| DBI.ZnT | Mar 15 2008, 03:24 PM Post #32 |
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What is Gibb's free energy G? As seen in chemistry class along with spontaneity and entropy. How does it relate to entropy and enthalpy (not the formula)? Think easy, diagram-like things. Simple textual explanations please. Wiki didn't help and my textbook is retarded. Maybe you understood better. Not to mention that this question isn't legit enough to go bother my teacher for it. He who is extremely bad at explaining. Edited by DBI.ZnT, Mar 15 2008, 08:28 PM.
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| Death T-2 | Mar 15 2008, 09:01 PM Post #33 |
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Somewhat Androgynous Lurker
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Will I ever be able to master In the Hall of the Mountain King on guitar? |
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| Chaos2651 | Mar 16 2008, 12:46 AM Post #34 |
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Lord Awesome
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Oh yeah, Chemistry utterly sucks. It tends to be explained in the most confusing way possible. I blame this on the fact they never explain why anything works the way it does (which is Physics's territory), so when you do get an equation, it makes literally no sense. I don't completely understand Gibbs energy myself, but I often have a knack for explaining things rationally--often more effectively than a teacher. So! Gibbs energy. Now, let's say we have hydrogen and oxygen. We want to make water. Our equation is 2H2 + O2 -> 2H20 (excuse the poor equation-ness that ZB has), though it doesn't matter much. We know we can create water from our two ingredients. However, in our air, we have a bunch of oxygen and hydrogen in there (actually, those are the smaller ingredients. Nitrogen (N2) has a bigger part in the air than anything else), and they don't spontaneously form water. If they did, then our breathing oxygen would be substantially... less now. In fact, what we need to do to our little particles is excite them. Both are stable as of now. They aren't going to spontaneously react with each other unless we provide a little push to them. The push, quite simply, is an addition of energy. Enthalpy is actually just another name for energy--more specifically, all the energy in something. So, in our case, we would need to create a positive enthalpy change to our little particles. Before you talk about entropy (which I'm trying to figure out a moment), let's go over some more things. Energy comes in many forms. Heat is the most obvious form of energy, so, for that reason, in chemical equations, we declare energy changes in the form of changes in heat. So, most usually, there is a change in temperature involved--obviously, since heating something tends to add temperature. When we add heat, we excite the particles. No, it doesn't mean they are anticipating the fourth Indiana Jones movie. They are excited because the particles are bouncing around faster. Now that we have the particles bouncing faster, the electrons in our hydrogen and oxygen are moving away from the nucleus of the atom. They have a greater tendency to move, just like the atom itself. So say our hydrogen molecules (the two of them) is all excited. They are moving. They are increasingly bizarre and chaotic--like a reckless driver. The oxygen is the same way. So the two (three actually, there are two hydrogen molecules here) of them meet up. Because they have a bunch of energy (enthalpy) inside them, their electrons meet up. And bam, the atoms collide, much like reckless drivers. With the reckless drivers slammed into each other like psychotic bumper-cars, there's a bunch of destruction. But the metal on one driver is sort of... fused with the other. The atoms are similar. Because their electrons are moving so fast, they want to go to something bigger because it's more stable. Whereas before, we had electrons orbiting just two atoms (because both the hydrogen molecule and the oxygen molecule have two atoms in them), now electrons are orbiting three atoms. They are more stable that way. Now, getting to the point, what is Gibbs energy. Gibbs energy is just the energy we added to get the whole equation to work. Sometimes, as I'm seeing in Wiki equations, it is expressed in changes of G, so, in our little example, there is an increase of Gibbs energy (and of course, energy as a whole). More specifically, Gibbs energy is the energy that actually did work. There's a small problem with the explanation, and that has to do with entropy. It is becoming abundantly clear that my knowledge of entropy has something left to be desired, but I will try to explain it anyways. See, Gibbs energy isn't exactly the same thing as the whole energy we added to the molecules. It's deducted by what is "unusable" energy. Basically, that's entropy. In our reckless driving example, we lost a lot of all the energy we could have used to fuse the cars together to the surroundings. That's a loss of heat. We can't get that heat back--hence the unusable part. Friction, essentially, is unusable energy. The energy we lose to that becomes heat. And I don't know if you've tried, but you can't capture the heat back. It's gone. It's gone, but then it's not gone. The energy didn't disappear. It still exists... just, it exists in a completely useless form. Sooo... when we add the energy to our molecules, there is some unusable energy there. That's entropy. Equation time. G = H - TS G being Gibbs energy, H being enthalpy, TS being Temperature * Entropy. The enthalpy is the energy we added to our system. It is all encompassing. It's all the energy we have for our system. So, we have some unusable parts with that due to heat loss... or entropy (I'm not completely understanding how a particle can have unusable energy). We have to deduct the entropy off of our total energy. So, once we kill off the entropy, because we really don't care about that, we have the more useful kind of energy: Gibbs energy. Since all the unusable energy is gone, all of this energy can be used. And in particles' case, they use it in chemical reactions. To answer your question about spontaneity, of course, if you have more Gibbs energy, then the reaction will be more spontaneous. Something along those lines. I hope that explanation works. I'm no chemist, and I certainly am not a Thermodynamicist (new word!), so this certainly isn't my forte. Rest assured, though, this is better than any of the crap you can get anywhere. The book, teacher, and Wiki fails. So in lieu of that, come to the Oracle. The other questions will be answered tommorow. |
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| DBI.ZnT | Mar 16 2008, 11:49 AM Post #35 |
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You went a long way. ![]() Entropy is the number of ways things can be arranged, it is, say, randomity. Increase in entropy is increase in randomity of the system, in which molecules move, which requires energy (part of H). So free energy is the amount of energy left to do work, well, any potential energy that is not used by maintaining entropy (random). Hence the equation G=H-ST. All this at constant pressure and temperature. Right? Is there anything as G universe? |
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| Chaos2651 | Mar 16 2008, 08:16 PM Post #36 |
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Lord Awesome
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Aha! Someone actually teaches me something! Wonderful. That makes a lot more sense for entropy. Essentially, it doesn't matter what temperature and pressure the reactants are. They could be in space, for all we care. Atoms can react anywhere--it's just really hard to find them when they do. All that changes is the enthalpy, because apparently, that has something to with pressure. But the equation should be true regardless: the values in it will just be different. Now. For the others.
Because that quantum probability is extremely low. Infinitely low, in fact.
That quantum probability is far higher. At some point in your life, you shall master this song. |
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| DBI.ZnT | Mar 17 2008, 08:05 AM Post #37 |
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Can it be that the Star Wars universe is just a parallel dimension (or whatnot) and that one will be able to access it sometime in the future? And what is the probability for one to find their soul mate on Earth? |
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| Chaos2651 | Mar 18 2008, 12:02 PM Post #38 |
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Lord Awesome
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Star Wars can be a parallel dimension--it is quantumly possible. Also, fans probably have high hopes of its existence, so that probably helps the... probability. The future is a long time, though. It could be possible that we can access other dimensions, or it could not. The probability of finding a soul mate is more than one and less than a million. |
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| DBI.ZnT | Mar 18 2008, 03:30 PM Post #39 |
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O: Star wars! Lol at second answer. The probability is in itself a probability. Or something like that. |
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| Chaos2651 | Mar 20 2008, 06:14 AM Post #40 |
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Lord Awesome
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That is not a question. Probably. |
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| DBI.ZnT | Mar 26 2008, 08:06 AM Post #41 |
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Do you think that YC will revive? |
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