mtv fully faltoo movies free download of work let's say you had it in some container, and you did something with that container, and it ended up actually expanding the container, and the piston did work on it--like a gas enginewell, ap chemistry spontaneity entropy and free energy answers it's not only heat, not only bonds--but it's also work: so, three forms of energy. Free Energy. Zip Code. So, the property for driving certain processes spontaneously forward and this word, spontaneous, is going to be very, very important in a minuteand others not, is a property called entropy. Test names are the registered trademarks of their respective owners. So again, don't lose any sleep if you don't necessarily understand; if you were able to follow what it is ap chemistry spontaneity entropy and free energy answers I have discussed in today's lesson, and it at least made ap chemistry spontaneity entropy and free energy answers to you--if the arguments were plausible--that is it; you are in a good place. Post by Jason Smith on October 15, ">
Possible Answers: It is greater than zero. More information is needed to determine the gibbs free energy. Correct answer: It is greater than zero. Explanation : If Q is greater than K, the reaction has exceeded the equilibrium state.
The entropy and enthalpy of a reaction are both negative. Is the reaction spontaneous? Possible Answers: The reaction will be spontaneous if and only if the magnitude of the enthalpy is greater than the magnitude of the entropy. Correct answer: The reaction will be spontaneous if and only if the magnitude of the enthalpy is greater than the magnitude of the entropy times the temperature.
Explanation : A reaction is spontaneous if the Gibb's Free Energy of the reaction is negative. Possible Answers: positive enthalpy.
Correct answer: positive enthalpy. Explanation : The Gibb's free energy equation is used to determine the spontaneity of a reaction and is written as follows:. This means these are the conditions that will always result in a nonspontaneous reaction. A chemical reaction has the following changes in enthalpy and entropy.
What is the temperature range for this reaction that allow it to be spontaneous? Possible Answers:. Correct answer:. Explanation : A reaction is spontaneous when Gibb's free energy is negative. As a result, any temperature that is greater than K will make this reaction spontaneous. Consider the following reaction in a galvanic cell:.
Which if the following statements about the reaction is false? Possible Answers: Gibb's free energy is positive.
Correct answer: Gibb's free energy is positive. Explanation : A galvanic cell results in a positive cell potential from a spontaneous reaction.
What is the Gibb's free energy for the reaction under standard conditions? Using these values, we can find Gibb's free energy for the cell. And, if heat flows out of the system, then Q is negative; that means the system had a certain amount of energy; a certain amount of energy flowed out as heat; now there is less energy, so it's negative; it lost heat--exothermic.
OK, now as far as work is concerned: work done by the system in other words, if the system does work on the surroundings--for example, if a balloon actually is the system, and it expands--it is pushing against an external pressure--it is doing work on the surroundings --in that case, work is negative. When a system does work, it is as if it's losing energy; again, work is just another form of energy.
You can think of it as just something else that flows: heat is something that flows--if it flows out, well, that means the heat is negative from the system's point of view--it's losing heat.
Well, if the system does work, that means it's losing work; that is it--work is just something else that flows. Don't think of work the way that we use it in daily language; work is just a form of energy that flows, either in or out, like heat, like water OK, now if work is done on the system in other words, if the surroundings does work on the system--that means it is putting energy into the system , the work is positive.
Work is positive: so this change of energy--you can have both being positive, both being negative, one positive and one negative, or one positive and one negative. There are four possibilities: and the sum of those is going to be the change in energy of the system. OK, now let's define what a state function is let me go ahead I'm used to calling it a state function, but I think it's better to call it a state property.
Anytime I hear the word function , I think of some mathematical function, which is very odd. It is just one of those words in science that is used, and I think it is more confusing; so when you see the word function in science, think "property," OK? A state property which makes more sense, when I actually define it is a property of you know what, I think I need to write a little bit better here, because this is important the system that does not depend on the path the system took to get there.
The best way to think about it is this: if I start on the ground level of My change is just 20 floors; however, the path that I took was up to 50, down to 10, up another It doesn't matter how I got to the 20 th floor; what matters is now, as far as, like for example, my potential energy--it is just the difference between the ground level and the height of the 20 th floor.
It doesn't matter that I went all the way to 50 and all the way down to 10 and back up. In between doesn't matter; all that matters is where I start and where I finish--my Initial and my Final. Heat and work very much depend on the path that I take to get there; so, for example, if I'm pushing a rock up a hill, I can push it just directly up a hill, or I can push it around the mountain, around the mountain, around the mountain, and then finally, I get to a certain height.
Well, there is a big difference in the amount of work that I have done, believe me! What is interesting is: if I measure the change in energy of the system, it actually doesn't matter; it's the same, no matter which path I take. So, what is kind of curious is that energy is a state function: energy at the beginning of the system and energy at the end of the system, after something has happened--that change doesn't depend on how that change took place.
But the transfers of energy--the heat and the work--those actually are not state functions; it's very, very curious that that is the case. OK, now let's talk about work: most work in chemistry will be pressure-volume work. In other words, you will have a container; it is at a certain volume and has a certain pressure in it; let's say you push the piston down--you decrease the volume as you increase the pressure: pressure-volume work--there is work that is being done of a pressure-volume sort.
Well, the work that is done is equal to minus the pressure, times the change in volume. There you go: the change in energy of the system is a sum of the heat that is transferred in or out as heat, and the work that is done by any pressure-volume change. Add those two, and that will tell you what the change in energy of the system is.
OK, that is very, very important; it's not the internal pressure of the system--it is the external pressure. It is the pressure that causes a compression--the external pressure--or which resists an expansion.
The pressure on the inside is trying to push out; well, the pressure on the outside is trying to keep it from pushing out--it's like you trying to open a door. Any time you are given a problem, and you are not exactly sure what this P is supposed to be, unless it specifically says "the pressure in the system" which, in the case of pressure-volume work, will never say that , this P is always the external pressure. I personally don't like the word enthalpy: heat--let's just call it the heat, and I will actually show you why it is the heat.
The definition of enthalpy is the following: the enthalpy of a system is equal to the energy of the system, plus the pressure of the system, times its volume. If I take the energy of a system, and if I can somehow measure it, and then if I measure the pressure and the volume of that system, multiply the pressure and volume, and add it to the energy that is there, I get something called enthalpy.
Well, if we do constant pressure, if we keep P constant, we can pull it out--there is no change in pressure, so it's only a change in volume; and this equation becomes the following. That is what is amazing; so this is at constant pressure--very, very important.
If they say "constant volume," not "constant pressure," this is not true: constant volume is a different process altogether. Those of you that go on to study engineering, thermodynamics, or as physicists, you will discuss constant volume processes; but in chemistry, we generally like to keep the pressure constant; it's easy to keep the pressure constant, because, well, if you are running a reaction in a beaker, the pressure of the atmosphere is constant--it doesn't really change much: so "at constant pressure" is very, very important.
For those of you who want the fancy name for it in science, it is called isobaric. OK, but it's best probably not to throw around words like that; just say "constant pressure"; it's better to go like that. OK, so let's see: Enthalpy is also a state function; it doesn't matter how you get to where you are going. Remember Hess's Law, where, if you have a reaction The change in enthalpy will be the same; how you got there doesn't matter; so enthalpy is a state function--is a state property.
OK, now I probably should have told you this in the beginning of this particular lesson: this lesson and, more than likely, the next lesson, are going to be more discussions; they are going to be more qualitative things.
Remember earlier, when we were discussing equilibrium and things: it was really, really important that you understood the chemistry.
If you understood the chemistry, you could decide what is going to happen next, and you can adjust the mathematics to make it match the chemistry, as opposed to wondering what I do mathematically. This lesson and the next lesson are going to be ways of wrapping our mind around these things that are new, things that we have never really thought about before.
We are going to introduce entropy in a minute: energy, enthalpy, all of these things floating around, and later free energy I just wanted you to sort of be aware of that; we will get to the math eventually, but I want to lay a reasonably good foundation; it's very, very important.
OK, so one last thing: exothermic--an exothermic reaction: that means it loses heat from the system's point of view; that means heat is going away. That means the heat is negative; so that means the enthalpy, which is the heat, is less than 0. Endothermic process: well, an endothermic process absorbs heat; we are always looking from the system's point of view--that means heat is positive.
We will take the combustion of methane: CH 4 which is methane, a standard gaseous hydrocarbon , plus two moles of oxygen, forms one mole of CO 2 , plus two moles of water. That means , Joules of energy as heat is released; that is why, when you burn something, it is hot--that is what you are feeling: you are feeling the release of energy. It basically says this: When we have CH 4 , and we have O 2 , there is a certain amount of energy associated with the bonds in those molecules.
Once I ignite it and I convert it to CO 2 and H 2 O, there is a certain amount of energy associated with the bonds in these molecules. Well, the energy in the bonds of these molecules is a lot lower than the energy in these.
OK, so here is our sort of take-home lesson: the first law which is essentially what we have been talking about of thermodynamics we'll just call it the first law gives us an accounting tool, a way of keeping track of energy flow and the different forms it can take. That is it; that is really all the first law is--the change in energy, heat, work, heat released, heat gained, exothermic, endothermic OK, all right: Total E is constant which, of course, you know: energy is conserved.
So, this is concerned with how much energy is involved in a change; that is it--this is what the first law tells us--it tells us how much energy is involved in a process. In this case, it's exothermic: it's out of a system--the system is releasing heat. Well, we have two forms here: we have a whole bunch of energy here; here, we have energy in terms of bonds, and we have energy in terms of heat so two types of energy going on.
If this release of heat actually ended up doing some kind of work let's say you had it in some container, and you did something with that container, and it ended up actually expanding the container, and the piston did work on it--like a gas engine , well, now it's not only heat, not only bonds--but it's also work: so, three forms of energy.
OK, so that is what the first law tells us, and that was pretty much what we discussed when we originally discussed thermodynamics in the context of thermochemistry. So now, we want to look at another question that we want to answer: How do we answer the following question? Here is another question we want to ask--so now that we can account for the energy and find out how it's leaving, how it's coming, how much is involved Or or I should say "and," not "or"--there are actually two questions that we want to answer --and, why does it happen in the direction that it does happen?
Why do we age? Why is it that, when you burn wood, it turns into carbon dioxide and water? What happens if I take carbon dioxide and water and try to heat it up again in a flask--why doesn't it turn back into wood? These are very, very valid questions; so we know, from our experience in life, that things tend to happen in a given direction, that if we want it to go in the opposite direction, one of two possibilities: 1 It's really, really hard to go in the opposite direction, to reverse something but if we put enough energy into it, and enough effort, we can actually make it go in reverse , or it's completely impossible to actually make something go in reverse.
For example, aging is a perfect example: we don't know how to reverse the aging process. Why is it that we would age? Well, as it turns out, we do have an answer for it; and that is what we are going to discuss. So, let me just throw out a couple of other things--a couple of other examples. If I take some iron, and I just sort of leave it out there in the rain and air, it rusts; you know that; but why is it that rust never turns back into metal--never turns back into iron?
That is kind of annoying; just naturally speaking, why does it go in only one direction and not the other? Well, OK: here is one of those times when I am going to throw something out, and it is going to feel like I just sort of pulled it out of the sky; but I am going to ask you to take it on faith that this is what it is.
I am going to introduce a new thermodynamic property, and it is going to be this property that is going to answer these questions. And again, I think, as we sort of go on to discuss this property, it might make a little more sense--it might be a little more satisfactory of an answer. But, this is sort of part and parcel of the elusive nature of thermodynamics--that we are able to identify this particular property that we are going to mention, and in some sense, it may be easy to understand, and in another sense, it's not really sort of easy to completely wrap your mind around.
It is not exactly intuitive; so again, I just wanted to warn you: this property that I am going to introduce--I'm just going to introduce it as: that's it. I'm just going to put it in front of you and say, "This is the reason why something happens," "why these things happen in a given direction," or "why something happens in one direction and not in reverse. OK, so I'm going to actually do this in red, I think; let's go with red So, the property for driving certain processes spontaneously forward and this word, spontaneous, is going to be very, very important in a minute , and others not, is a property called entropy.
OK, here is what entropy is: you are going to love this definition--I'm not sure if it is going to make much sense, but here it comes: it is a measure of the disorder of a system. I'm going to use another word, and I personally like thinking about it this way.
And, as we do some of our problems in the future lessons, you will understand why it's better to think of things in terms of chaos, as opposed to disorder; but essentially, it's the same thing.
OK, now, let's start with some important equations: the entropy of a given universe is equal to the entropy of the system, plus the entropy of the surroundings. That means, as it turns out, when we speak about entropy, we are often talking about the entire universe. When we want to measure the change in the chaos of a given universe, it is made of two components: we have to measure the change of chaos in the system, and we have to measure the change in chaos of the surroundings of that system. And again, both can be positive; both can be negative; one can be positive, one could be negative; and this is what we are going to investigate.
OK, I'm going to state the second law of thermodynamics, and then we'll move forward from there. I don't know if I should do in on top or on the bottom; you know what, I'm just going to do it down here.
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Chapter 9 Feedback Form. Intermolecular and Intramolecular Forces. Molecular and Ionic Solid. Network Atomic Solids. Structure and Bonding in Metals.At what temperature will it change from spontaneous to non-spontaneous? Approximately K. If the reaction quotient Q is greater than the equilibrium constant Kwhat is true about the Gibbs free energy? If Q is greater than K, ap chemistry spontaneity entropy and free energy answers reaction has exceeded the equilibrium state. The reaction will be spontaneous if and only if the magnitude of the ap chemistry spontaneity entropy and free energy answers is greater than the magnitude of the entropy. The reaction will be spontaneous if and only if the magnitude of the enthalpy is greater than the magnitude of the entropy times the temperature. The reaction will be spontaneous if and only if the magnitude of the entropy is greater than the magnitude of the chemitsry times the temperature. Ifthe enthalpy, andthe entropy, are both negative, then the reaction will be spontaneous if and only if the magnitude of the enthalpy is greater than the magnitude of the entropy times the temperature. The Gibb's free energy equation ap chemistry spontaneity entropy and free energy answers used to determine the spontaneity of a reaction and is spojtaneity as follows:. In ap chemistry spontaneity entropy and free energy answers for a reaction to be spontaneous, Gibb's free energy must have a ap chemistry spontaneity entropy and free energy answers value. Based on the equation, we can see that a positive enthalpy in combination with a negative entropy will always result in a positive value for Gibb's free energy. A reaction is spontaneous when Card battle games pc free download free energy is negative. As a result, we need to determine the temperature range where Gibb's free energy is less than zero. Since we know the values for changes in enthalpy and entropy, we can plug them into the Chrmistry free energy equation, and set it equal to zero. Since entropy is positive for this reaction, increasing the temperature will result in a more negative value for Gibb's free energy. A.P. Chemistry Practice Test: Ch. 16 - Spontaneity, Entropy, and Free Energy Choose the one alternative that best completes the statement or answers the. AP Chemistry Resource Center. Chapter Spontaneity, Entropy, & Free Energy Subpages (11): Entropy And Its Relation To Spontaneous Chemical Reactions Answers Practice Problems(Feel Free To Add Any Additional Problems). AP Chemistry. Name_. Name. KEY). Date. Ch - Spontaneity: Entropy & Free Energy - Practice I. 1) For which reaction do you expect change in entropy (AS) to. What can be said about a chemical system that has reached a minimum in free energy? answer choices. The system has achieved equilibrium. The reaction is. Chapter 17 - Spontaneity, Entropy, and Free Energy Free Energy (G), also called "Gibbs Free Energy" Entropy Changes in Chemical Reactions. General Chemistry II. Jasperse. Entropy, Spontaneity, and Free Energy. Extra Practice Problems. General Types/Groups of problems: Evaluating Relative Molar. The second law of thermodynamics says that the entropy of the universe always At constant temperature and pressure, the change in Gibbs free energy is In chemistry, a spontaneous processes is one that occurs without the addition of The short but slightly complicated answer is that we can use the second law of. AP Chemistry. Name. Period_. Ch 17 Entropy and Free Energy What is AG and spontaneity of the reaction? of °C. Calculate the entropy change for Answers: For the process at 25°C. 12(g) → 12(s) what are the signs of AG, AH. AP Chemistry Chapter 17 Practice Test. 1. For which process B) The total energy of the universe is increasing, but the entropy is constant. C) The total energy. AP Chemistry. K inok. Enthalpy, Entropy and Gibb's Free. Energy. Active Learning Exercise --KEY An AP Chemistry student Justify your answer, If a reaction is not spontaneous, or is thermodynamically not favored. About Course-Notes. Advanced Chemistry pd 1. With the help of the community we can continue to improve our educational resources. Chapter 7. Chapter 11 - Mrs. Answer Key Chapter Answer Key Chapter 8. Packard's Chemistry Classes. Activity Index. Answer Key Chapter 7.