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Thermochemistry: Work, Heat, & First Law of Thermodynamics

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right 1st and announcement the fabrications and that what you want the bad news is we made a mistake in rating yeah would you want good the good news is we are too lazy to dig through all those stand file so that give everybody 1 was the that the rise in the next few days now next exam I assure you we are not going to make any mistake I think that the state was only on warm the 1st 2 rounds call back but we don't want the prolong lowered his major major everybody you got that right there you go again I think some of the needed those 2 OK let's continue to today we're going to talk about their most chemistry he worked on the 1st floor of the remember scientific launches generalization that after race and the law only applies In the limits where you there is not outside of but we pretty much observed things like heat and work for eons and winning feel that we understand what's going on very well however it's interesting and very difficult to define it's everywhere the Commission contend has itself in different forms ever-present never read to Reuters created in a way and he is the scientists God difficult to understand but everywhere we can broadly
classified energy this is turning broad brushstrokes but it will did In 2 forms where can he and work is much more useful nobody says I'm going to go to the and the money Nowhere is going to be the useful kind of energy and useful for us is going to mean that whatever you're going call work can be converted 100 per cent the lifting away and the surrounding that's what you can do anything that that's going to constitute work and if we want to get the energy back we let where dropped and we do something with the elevator that has to go out is doing work because you're calling the compartment 1 although hundreds of people on board and that's why you take the stairs the elevator Close to not waste energy people will figure out what the term waste energy me a little bit later since energies conservative can't possibly waste because of cost he is the amount of energy that can be used to raise the temperature of something like water about taking gas flame I can he water but I can't lift the barbell of With gas no matter how many how much I put the flames on him from below heated up like crazy I noticed that it doesn't go anywhere and that's because we disorder and that's how politicians energies and the media as the every
jewel of energy and others you and your home last year according this year the and that's control because it gets too hot you sweat words open a new start evaporating water and was a big worry about the runners but of course they overdid it and some energy can have both work and the just depends what's so work
is a coherent directed form of energy and object it's moving it's a macroscopic thought and it's moving and all the atoms and molecules in the office Our moving together the help you buy there intermolecular forces and by chemical bonds and then the whole thing all the atoms moving together that can happen by accident that somebody doing something something the rocks don't just start jumping up on the ground yeah your I picks this up your ideas a derivative Tech that's why animals when we walk around status fulfilling straight line but if they move you know it's not the lot you look see the found camouflage themselves by playing dead just sitting there you see coherent something coming moving it could be dangerous methods the new runs it's a rock and a hard get out of the way but you know this right away that's why you don't want a device that has moving things on it the distract your when you're doing
something else just walk often fall down the stairs with you fiddling around with batteries are elected chemical devices talk about them that and they can be used to do work on In an electric cars or an electric trains and so forth and it could run on batteries although as it turns out batteries and solar wind but they are very very useful yet he on the other hand is an
incoherent undirected form of energy In the case of the what happens if the atoms are basically moving faster if we them up but they aren't moving together and that the huge difference I can have a lot of energy the plight the it's useless to get something done unless I resigned the engine of engine because over some of the work force by the families he I think some of the you're put here for the flame under there's plenty of energy and by figure out how many you will but because it's all random I don't have any coherent motion from the ball and have to to do something special might have McAmmond with a barrel and then I blow something up and then the compressed gas wishes and I only get a fraction of the energy into the projectiles the rest heats up the barrel and everything else so I to put in more gunpowder than I actually I would say together 1 squared for the project where can be 100 per cent converted into heat for example by operating an electoral votes well a scientist I do decided to monitor his power like the power consumption really connected
himself up with Google made where he could see instantaneously with electric power consumption on farm the 1st thing we did start unplugging all the vampire devices the electric toothbrush charges Shaver and every time we unplug something you don't need it he gets ready to go on instantaneously because you never heard on the of body and after a while you thrown away and the space books 1 morning with a a will and suddenly the electric power consumption when asked pass these looking around what had happened His son was making these the next day this sorry Foster converting working heat like that should be a crime if you want to give up your office you can either have an electric heater just turn it on nothing at this week's Iraq the euro will hold a news this jumping you can do a calculation on your computer and it'll produce a and it population again so when I told him my office I just a little bit of work mathematical and on and off and that's it we can't unfortunately converts heat back into work 100 per cent efficiency he was converting heat the work would be like herding cats which we just yeah yeah all the atoms and molecules to start moving In unison together when they're just going every which way because we can't get in there was little tweezers and sailor start behaving we can't control and therefore when we degrade Tennessee in finally entered he we've lost if we we drop a rubber ball on the floor it has potential energy and Ch when I start and then I let it go and it bounces and it doesn't come quite back even if it's a really good 1 and for the same price and if I just wanted to go on and on and on and on John and the question is where the energy goal and answer is both the ball and the floor are little bit warmer but because of the conversion between here and work it takes quite a bit of work and make a lot of the that you would know that and that's why if you go camping forget matters and the state I'm going to get to the states and start doing this you'll find out how extremely difficult it is to a fire going by that you have to be incredibly determined and you have to have forearms status hands too so that you don't get too tired and stuff and cools off the very inefficient way it doesn't fact work but so I wouldn't rely on if there is a little rain for day you never get and this observation that
extracted Jewel and perhaps even before duel that the energy Interchange forms but is always concern is the 1st floor of the middleman In a nutshell energy is conserved no 1 Southern California Edison sends me a fire the statements their energies I want all my principles that I possibly Have you heard of the 1st floor cost what they really mean is don't convert useful form of energy into a useless form of energy that's a little more stock more accurately the energy of an isolated system is constant and isolated system all give a definition a little bit later but an isolated system is 1 that cannot exchange May ask for as he at work with the environment and we can consider the universe of a bigoted would be an isolated system and we've included everything and then however much energy it had when it was created is how much it has today it's a constant number of jewels and astronomically base but that's it and when stars burn burning mass and energy into heat so they're degrading the energy that taking useful form of energy and turning it into being and they will all burned out eventually and and Everything will be gone at that point OK he usually we get the letter you I have no idea where the letter you came from but conventional small letter we reserve capital letters were good things which will state lot capital levels and small letters that aware the things that aren't as we reserve for things like he he will slow between 2 objects and thermal contact if they have a different temperature that may sound a little bit circular but that essentially how we imagine he if we have to object and different temperatures but if we zoom in on the patterns in the sky you know we have now are just moving fast he added this gh Our move "quotation mark if I bring them into contact thermal contact the time and
the and this guy Alexis Ahmad Ali who will move movement the began right and what happens is they get these guys moving fast and if they move faster than had the next guy and so forth and we get a flow of energy which is just like a water downhill we talk about the flowing from 1 place to another as we watched just the excitement move just like what where stadium just everybody stands up and the impression is that the ban on the movement of as this excitement propagates we talk about the slowing from 1 place to another there are other
forms Of course we talked about work and I told you what work is electrical energy has also ordered energy we can you work with them an energy can also be stored in different kinds of chemical compounds poll natural gas or oil partisans you name it where did all the chemical energy but were pilfering now from the fossil fuels were to the conference anybody yet the series exactly right and how would you and cereals built up since it takes work to build up molecules like that no From the sun it all came from the sun have son of nuclear so everything instantly because all of the nearest geothermal and nuclear without nuclear you about remember that as time goes on the plants die after they build themselves up build cellulose and other things but he died and it down and they get compressed under a proposal pressure and there is a phase diagram you squeeze the oxygen out and start making long oily things that compressed business things go down there may get compressed like Tracy preferably you and they sit there a long time so they got millions of years 2 change that and we put all that energy in from the sun every day all those plants millions of years and then we burn it all up in 100 years the optimists say Well we've only gone through half the oil but you've got to 100 million years of oil in 100 years that's not good for us we did that when none of you were here 2 when I was a kid none of you were here now you're all driving around what do you suppose to happen the sustainability of our model it's a big words Mass itself this is the myth of the Sun News and nuclear power plants mass itself can be partially converted into yeah the beauty of this is that
the square is a huge number and I understand that the 60 that's a lot of energy that you get from a little and that's why the sun can keep on burning incredible power output this was impinges on the earth a 93 million miles there's a minuscule fraction of the total power output through the whole is unbelievable power prominently we just can't harvested the very efficiently there's even more energy in some distant quasar millions of times more than the sun but that's also useless for unfortunate there's plenty of energy around but it may not be where you can get In the fossil fuels have turned out to be the easiest together any kind of form of energy can be measured and jewels and that's how we usually do it and whatever you do with work it's eventually converted into heat all and that's where it ends up and then the Fed's he all at the same temperature it's useless because you can get in the flow of things at the same temperature we can't get anything done eventually the whole universe schools after the same temperature and that's that OK some
conventions for convenience we divide the universal into the system that's what we're interested in and the surrounding here's everything out we usually focus on the system we're talking about thermodynamics but we have to keep in mind that the surroundings are there and usually the surroundings take a beating the surroundings get the great systems may be that means they can exchange both mass and energy or they can be closed and they can extend its energy that could be like a close where I have a chemical reaction and he would come out in the lab but no chemicals ,comma no matter the exchange anyway that systems or it could be isolated it could be unable to exchange anything with the surroundings an approximation for that is a very good Germans are very good where we don't let any heat treatment from its surroundings and we don't let cold ,comma EPA will just keep everything this insulated and we keep a lid on it we don't ever look in he isolated systems of course on idealization just like an idealized gasses through isolated system doesn't exist except maybe you consider the entire universe and and that's kind of a traitor because then there's nothing outside which should of course it's isolated because it can exchange something with something that's not there
thermodynamics refers to systems that are not changing too fast there at equilibrium or they have appeared to be have settled down thermodynamics is the science of after the smokers clear what is it like kinetics exactly how did the Bongo and that's much more difficult thermodynamics is extremely advanced because it doesn't care how you've got something to be the doses where you start where did you finish Greg not even the theory kinetics paid exactly how did that the thing happened on the sparkplug fires which hadn't starts reacting which I didn't comes off powders that propagates that's much more complicated and that's incompletely understood even today at a state function the
capital letter is any quantity that depends only on the state of the system not how you got there it depends only on the state of the system for example I could have water in equilibrium with 5 I guess that's a Scotch Our I hope is some from the doctor's office perhaps or I could have water in equilibrium liquid with vapor here N the specified the state of the system we have to specify the temperature and the pressure the phase and the composition if we have more than 1 kind of stuff in there we have to stay with the mole fraction of each thing and once we specified all those things there then numbered anemic says I don't care how you get there and I don't care if you froze the 1st and let some of the law or how you did it you tell me how it is now and I'll start giving users kinds of properties that are conserved certain things you can rely on once you specify the state of the system where interested In changes in state because a chemical reaction is nothing other than a change in state we start with particles over here electrons protons and neutrons In most chemical reactions of protons and neutrons just sit there and then the electron buzz around and they give us a product and as a chemist what we want to do is we want a word lists reacted you
somewhere and come out with a very very expensive product but we which are made of the same Adams with the reign what we wanted How manure and end up with state things like that and we can make money doing that because once much more valuable than the other In a course that's what a farmer does that but the company the corner grows corn they feed again run around and here's a state function managers called F for
function and we have an initial stake and a final state and the change is the final minus the the staff went up and this is bigger the final value of that is bigger than the initial value than the change in South is positive if it is lower than the change in this negative and the value of the important thing is that the value of Delta depends only on where he started worry and and not how you did it you can't do it any the including and this is the 1st quarter imaginary ways you can imagine away the Gulf from year to year that's fun still work because you don't have the so it doesn't have to be something you actually did something you imagine it might be possible and that that's the power of this approach because we don't have to do every kind of experiment in the Milan we can do a few simple experiments and then we can add subtract and get what we want we don't want to have to do a complicated experiment gravitational but the gravitational potential energy is a state function just depends on how high the masses but I got there and all the capital H is a state function we're going to talk about war the Internal Energy Capital you free Energy Capital G. entropy the capital S call Energy Capital a console whenever he sees
capital letters you think that's a state Farm and we use a capital case for an equilibrium constant and we always use a lower case pay for another variable because that's going to
depend on how you do it strictly speaking a state should not change in time which is kind of a contradiction because we're talking about changes in state following mean and we start somewhere knowing that we ensure that not since changing now let something happen and that we make sure not further changing again and witnesses the difference from what he produce In accelerometer or what have you and then and then we measured the change in state but we don't want them to move around too much while we're actually trying to measure them because then we have a lot of difficulty defining what the state operationally then we can define a state as a situation in which the slow enough change or small enough change Over time that we can make an accurate measurement we can home in on it and say OK we've got the crosshairs on and it's not moving too fast we can see what we want measure we can measure the temperature and pressure the composition good ready let the reaction go and then it settles down and we measured against if we have a temperature that means and as we saw gasses that have characterized metal and distribution and if the gasses at a constant temperature than the molecules have the following that distribution and that means there's moving in certain ways and other things that vibrate to the vibrating slow or fast and the number
a each molecule but doing its thing should be changing all sometimes it's where you go faster slogan and they collide and now this fast this guy slogan but the total number has not this Saturday and if if if the low energy level occupation stay constant then we have such a thing as a temperature in many situations like in an explosion we don't know what the temperature is because things are changing too fast the measure anything the things are all over the place and so it's very difficult to talk about the state
OK there's a problem the I moved it In a uniform gravitational field Little change and I want know which of these have the same change in the temple anybody want have a go no analysts slower we only care about the initial and final .period and therefore the ones that have the same initial and final points of the 2nd phase of potential energy a The and he has said today the weather higher so there a difference in the life of the but notice we don't care what happened in between is the initial a point in the final .period with their back line is the same that's the same shade and state on but
why don't we terrible about state functions the reason why we
focus on state finances as we usually don't know what happened it's very difficult to know in detail what exactly happened I know what reactions I started when I know what products signed ended up with but I don't know everything that happened in the exactly which they did this in which intermediate payment and so forth for example you know piston in the car in an internal combustion engine I'd like to burn this stuff this stuff here the ISA the 100 on me again that's the stuff you can buy ,comma builders who spent a can actually even better gas man I think there is 1 place in Malibu self death toll free at 104 . 9 and also starred in last year's high-performance Our pulling out of the Presidium that expensive than the 6 bucks a gallon tank for that but anyway if you had I saw what it's got a carbons but notice that it's not a linear and I think branch and it's very important for fuel the branch of the oil companies spend millions of dollars in figuring out how to pay for oil you get branched chain behind I and the balanced chemical equation then is this guy and 25 the 12 and a half miles of molecular oxygen give moles of C O 2 there's the climate change 9 moles of H 2 0 we know the
balanced reaction and we can measure how much he comes we can take Isa locked in I'm all of put it in an insulated containers and burn at all with oxygen completely and we can measure the temperature changes we can figure out how many jewels of the it produces no problem we can be there for any kind fuel but we don't know exactly which cards when the oxygen comes in certainly it is the
case that 12 and I have 1st of all happened comes in and which of these false offers what happened in there what you get all kinds of things 1 of them goes wrong In the Beauty is We don't care for the modern and it's always care about is how much heat we
get what we're gonna do we want to make sure we burn completely and car engine doesn't always do that part of the reason you have a catalytic converter we don't even know step by step exactly what's happening and that's important because we usually don't know that if we do all that we could probably designed much much better system OK so here's an example that means
again bye combustion of ISO what is minor 5 thousand 461 killer jewels from mole the negative side is important because that means that he is coming out negative Delta age means that he is coming out of the reaction it's producing heat and then it's going to the surrounding please include your hand there it feels warm for captain and had been a linear chain of 7 Carpenter the 7 8 16 the heat of combustion Delta age the end of the year combustion is minus 48 47 killer jewels for more Oh here's the question which fuel it is more efficient for Grant the constructive stuff around you don't really care from Molly care program because when you got stuff around the more costly to move around from let's figure out what the molar masses and then go from there but just in round numbers How 8 times 12 96 plus 18 is 114 now we got 84 close 16 100 but they have a slight difference because some versus a an octane than if you divide this by 114 is 47 . 9 killer UAL's per gram and heptane is better because 48 . 4 7 Village program because it just moved decimal points but in terms of octane rating I saw Martinez told a hundred on yet and end had thing is actually called 0 that is if you go to the stockroom and get this fall and the new law by somebody ,comma they're going to have a bumpy ride home and there
could have been taken the heart of the dealers or perhaps to a mechanic they don't get fleeced and that's because the octane rating has nothing to do with it the octane rating has to do where the is resistance to prematurity detonate what happens when we the fact that thing is that the 4th pillar of this and the bottom dropped we want to talk it actually starts flowing out and so on the engine gets all the same and the Pistons as opposed to run like you run legacy both B coherent then they fired from violence on and orchestra and if it started firing at random and you just lose all power is producing entity that is not producing any forward motion of the heart and this stuff the 100 arcane stuff is this move still Howard comes right out this never before you want to the complete control on this so it has nothing to do with the energy content of the fuel but rather how easy it is to convert the energy into
kinetic energy of the car and that depends on engines on other fuels have even higher octane ratings but they are much lower energy content and they aren't they may run very close but you need a much greater pain the gold standard With the fuel the 85 is 105 octane ethanol's 113 and ethanol just burning ethanol itself is 116 off again but in terms of energy content their lower much diesel His only 35 but a diesel engine has completely different design because in the diesel engines there is no sparkle In these all you 1st compress the airline praising the compression ratio from where started work on the a new injected fuel and blows up on itself on ignites and blows and at the end of month because of the compression ratio being very high a diesel
engine it can have very good efficiency but because of the way it works historically emissions event ,comma Britain a bike behind an old diesel cars don't know what I'm talking about you feel like you're being fumigated and so it's very hard to get the air quality to where you want to have with diesel engines you can do it but then there's extra costs the controlling the emissions and you have to pay for them and diesel fuel I used to be cheaper than gasoline but now is not necessarily cheaper than gasoline and so you have to take that into account focus have
why should we 1st the 1st loss With the gasses we better the pressure volume temperature volume we got Boyle's law Charles Alonso for but what about this how can we say that energy is in fact concern and the best way to show that it has to be true is to assume it's not true In fact when I was a post office yeah there was a guy talking to devise followed power enhances I think it was on Telegraph Avenue and what would do you put in some current and voltage and you get out twice as much per sample this thing wasn't connected anything was connected to the wall so just enhanced power .period he had a lot of people who were just hanging around listen to but not faculty in the sciences at Berkeley stopped freedom the list this proprietary devices facing the :colon when you ask them what's in the box demands as I can tell you the a black box I can tell you what's in trade
secret we'll see what what men you take in DC current 12 Olson of produces twice as much DC :colon all that sounds good but that's creating energy there and energy has to come from somewhere he believe the 1st loss and you pay a small one-time fee and many connect this thing up and he said he did this run twice as many thanks to power bills much lower also a foreign woman and you can run all everything in your house a little better ,comma again they were quite expensive like 500 dollars but supposedly they work forever so it's a good investment OK let's
construct an argument the demolished this device and prove that it can out of the question is how we probably gonna do it well it's supposed but it does what it says it produces more however and doesn't need to be connected anything and it keeps doing it forever while the 1st thing we could do this week accused 1 power enhancer the produces twice as much as we could see 2 power enhances laughter and since they produce twice as much we could be for power and dog the no
defeated insisting that we keep going and that it would and just a little bit error and we could power wholesale California as part of our large number of power in the this city and that they don't take anything no fuel no electricity no ,comma not this black boxes city we have to resources that that's 1 but an even more convincing argument is to do it this way you don't need to have thousands of devices and connect them up you can do it this way you
can use the debt since it produces twice as much what you do is you run out a certain what happened 12 holes around the input and then he just lead off 112 balls With not putting in any fuel not connecting about who I thought could not forever the United have a black box that is producing power from nowhere with no it's such a device existed I assure you we would be selling nobody has ever been able to do that and that's because a device like that is absurd I can't possibly work because it violates the 1st floor of the modern what was
in the black box some people it's just a runs a couple of hours and runs out How about these new jobs provided and the guys of at moment ,comma incidents were worse than he's going to 500 bucks for 100 all of them
heartless talk about the internal energy this is not quite so familiar example of the FLP we encounter all the time but internal energy it's just the energy contained within the system and the state functions and we're going to see that it consists of 2 parts for any system that can produce heat and wh whatever he worked the producers must add up to the change in the internal energy however the real power answer runs and the battery discharges the internal energy is the batters going down down down down as we and so what whatever he and water FAA involved they have to add up the total has to add up to the change in internal energy and this is another formulation of the 1st lot fiber system and it changes internal energy it has to add up to plus
and the question is can we use adult you can we any system undergoing a change from some initial the final state could the change in were also be written dealt Q is the heat of the final minus the heat of the National and Delta W is the work of the final minus the work of the initial and the answer is that doesn't work because a and this can exchange workers like your savings account and he is like rejecting the town and that too added together the value of
money and if all you do is move money from checking the savings here no Richard of but individually the account numbers move up and down and so it's only the total amount of money that you've got think the he cracked not what's in individual account and we can't do this alone we are allowed to do that because they are concerned neither he nor work is alone
is conserved and so we can't we just cannot know How much of the there is involved only from the initial and final state we don't know how much to eat and how much work it took to get there only the for example by friction we can dissipate a lot of work in the when you run your car tires get hot and the tires a rape you a
very powerful car you may have serious the ban the wider they dissipate heat more the terminal temperature of the time goes like this where the velocity and you can actually have a lower if you don't know what you're doing it's a hot day you're going downhill and you've got an economy car and you've got a low-temperature rated tires and then just over yet we may get much seasoning may lose control and then they may have a blowup which is not a good thing to do OK for an ideal gas we
have an equation of state but we know what state here's an equation of state 1 exit powerful because that means we can specify the date of the gap once we know these and we know how all the variables are hooked together for an ideal gas so we can take this so we can assume 1 wall of gas safer just for the sake of simplicity and we're going to keep the gas in contact whether the rest war for a thermostat at some temperature T star In a piston and then were going to
put masses on top to adjust the pressure and what we're going to try to do is to be tried a little too much man In the surroundings as we can With this Morgan tried several ways and see which way ends up With the most may ask the that's the most work that's what we wanted to typically used to do a lot of work OK so we're going to do some work by lifting a amassed or massacres in this case in the surrounding and what we're going to see Is
that the best way to do do it is unfortunately the slowest 1 that's also the best way to learn the worst way to learn is taken in our ports and then that's the end of the court you get exhausted on tensions if you don't follow something it's over and it's of limited utility the best way years you have a little bit every day that's about 24 hours a day at the right time but for scheduling reasons we rarely do that the reversible change will will define what it is in a 2nd but what it means is that if you change anything but just slightly you can reverse where he was you go backwards you can literally go back to where you were despite changing something slightly that means you didn't do anything very they're very slow in fact In theory the infinitely slow why processes like digest all lawyers on people coming from all time quiet processing tend be more reversible and hour the justice system is very good and extracting as much energy as possible From what you eat up to certain limits we are we cellulose cellulose of the cellulose mail only bacteria the bacteria break it all down and then the knowledge of bacteria the Federal Trade wipeout companies some of their 1 stomach for these guys want some of these guys and so forth if you got allowed sudden process like an
explosion or the roar of a race-car engines and that's very far from reversible you go out of the bottle salt flats in the powerful car and had no idea how loud they were until I was mistakenly standing there and I like that I don't think we should all over all over the ground and then there was the most incredible explosion I got and all the guys I was doing was resting his top fuel the spin the tires and the bleach and Red Cross so that when the race started to stick to the ground and people on that and I never went back there again after that because the the smell of bleach going on in the and being a little bit it wasn't entertaining and at that time I did drink beer so there wasn't any of that which everyone else I noticed seem to be doing but
unfortunately you know we can't wait forever week so the 1st lot has to do with energy but society has to do with power if you want to get something done you need power not energy however is energy plus do it now you watch an earth mover come and grab a ton of dirt and move it up and down over here that power the the guy's does is 1 inch at a time and takes all day because he's that solar panels power the U.S. 5 that's what we gotta get this foundation
that today we got so men on the moral accepted that power and you see that because when when 1 of those Caterpillar earthmovers digs into the ground this huge plume of black smoke comes out of the smokestack they don't have the same emissions controls here and you can just see the diesel going down in real time because it takes a lot of power with the times of material in the air and then move over here and and they are not going to be operating on battery anytime soon he put on earth mover on batteries does this up batteries but we don't
wanna run on diesel OK here Our situation here our Rosenbaum here's artist and we got 4 Masses on it N obviously if we don't move any of the matters involved nothing changes we can't get any worse we have to move the masses off and then the other to move up there's not pressure less than the gas which is we don't even know how traffic go through anything like that just no where in sight sentimentality ,comma work we and every we slide off 2 of the masses here on his imaginary shell they didn't change type so there is no work there but these 2 dead we got some work there let's figure out how
much work we can make the gas In this case while
the temperature doesn't change so 1 the 1 is an oddity star and that has to be able to feed 2 the it's just the way per unit area so the pressure is the total mass sitting on that play times the force of gravity divided by the area of the and because it's a piston assuming that the walls astray the volume is just whatever the area is times the height it doesn't doesn't need to be circular cross-section and that means that P times the but put these on is just equal to the mass times times the good well let's figure out what what what happens to the height the industrial state is the 1 being 1 it is for and G H 1 because the total masses for these little lambs she's there and the height is H 1 and the final state this came to veto is able to to only 2 masses dynasty 9 states to and since the story equal that means of
age 2 and each 1 I have to be related to each other every set them equal we can cancel out the ends and the Jason we find that age 2 is equal to 2 H 1 so that all we cared about half the aftermath and I think 1 of places high that's what water told us basically is going to happen no surprise how much work did we get while the work is where those masses started and where they ended the work we get we lifted up
to masses other 2 we letter and the difference in height is age to minus 8 1 so the total work we get us too times and times the force of gravity acceleration gravity and then each 1 and that's how much
work we got OK
suppose we take them off 1 at a time I'm going to be slower but the question is do we take them off 1 at a time were more patient are we going to get more work for less work the state 1 after the other 3 go up take 1 or the other to go up they won on the final 1 goes up they found 1 off then goes to infinity presumably but doesn't have any Mac that doing work OK we slide 1st mass of get work because it didn't change high the other 3 move up half-hearted they move up well to cut to the chase the other 3 move updates to equals 4 thirds H 1 this is a game of oil would have told at this place 2 we slide off the 2nd mass and so when we slide the 2nd mass off we get that mass sitting there at age 2 minor states 1 we get one-third MGH 1 2 from that 1st won the remaining go up to a new height which turns out to be 3 have staged 2 but we know what it's to is it's for 3rd stage 1 and conveniently the freeze Golway we find a ceased to 8 1 while in created before we go it once we slide off their 3rd here the work we get than his Ng age 1
and the final menace many of the of the year the other go up in the final
mass moves up to a height age 4 where forest to aged 3 and that turns out to be for a while and the work we get is that final Mass and the difference which is 3 therefore the total work there we got His 13 per 3rd cent 78 1 which is much bigger than and our conclusion then is that by doing it more slowly we get more work the important thing here is that only the pressure difference between the inside of the container on the outside and the year if the insides at 1 atmosphere in the outsides of 1 atmosphere nothing's going anywhere when you do that we have to have a preference difference the gas has to be at higher pressure initially then the external pressure otherwise we don't we can't do anything we can blithely assumed the external pressure was 0 here but the external pressures usually atmospheric pressure and this different sets an upper
limit on the amount of work that we can get In a real system but people were scheming to use exactly the gas and on the on a grand scale all the intermittent problems of wind and solar energy and when the wind's blowing their compressed air and when the wind is not blowing they're going to let it come out and get the energy this is called off-peak storage there's 1
scheme you take cool air and when you wind and solar power running you run a compressor but they were clearly have electrical energy from the wind and solar you compress the air into this huge old coal-mining old gas on something and you will never leads gradually reduce the rate of and then when you need the energy that nothing's come here now he led the ear canal and it's under pressure and driver further to the right generating generate electricity at nite for 1 year the we call go to these guys and I know if they're out of business here and you can also use the waste motor he taking the year on the way out to the schemes to actually try to make and my comment on this is probably won't work well In other words it's easy to think of all kinds of you'll see millions of them on the way the question is if you want power of the state of California overnight or for a week when there's no wind How big is this thing this smolder and this thing and if things have to be How many of them the evening and the answer there is
usually it's so given that it still only on the question because you're going to have to pay for all these things don't come for free and you need an energy source to manufacture all of them the words get their energy when you've burned up all your fossil fuel and you have no other energy source if you try to make solar panels by only using solar panels to power the solar panel factory you're going to get 1 panel for a year or something and then going to see how long it's going to take if you want a truly sustainable going forward would have to say things that kind of issues thermodynamics always gives us the bottom line that says you cannot possibly do better than that and that's not good enough then you need to think of something else will continue on this than on next Tuesday
Chemische Forschung
Bukett <Wein>
Oktanzahl
Thermoformen
Besprechung/Interview
Gezeitenstrom
Reglersubstanz
Wasser
Substrat <Boden>
Besprechung/Interview
Wasser
Körpertemperatur
Advanced glycosylation end products
Computeranimation
Edelstein
Destillateur
Körpertemperatur
Bukett <Wein>
Thermoformen
Körpergewicht
Krankheit
Flamme
Druckbelastung
Derivatisierung
Primärelement
Gestein
Reaktionsführung
Chemische Bindung
Thermoformen
Besprechung/Interview
Primärelement
Molekül
Chemische Forschung
Ordnungszahl
Molekül
Computeranimation
Vimentin
Reglersubstanz
Fülle <Speise>
Feuer
Wursthülle
Potenz <Homöopathie>
Besprechung/Interview
Phthise
Ordnungszahl
Barrel <alpha, beta->
Konkrement <Innere Medizin>
Computeranimation
Konvertierung
Landwirtschaft
Katalase
CHARGE-Assoziation
Bewegung
Latex
Thermoformen
Gummi
Molekül
Flamme
Wasserstand
Feuer
Enzym
Besprechung/Interview
Chemische Forschung
Wasser
Durchfluss
Körpertemperatur
Computeranimation
Edelstein
Calcineurin
Stockfisch
Körpertemperatur
Thermoformen
Systemische Therapie <Pharmakologie>
Enhancer
Bodenschutz
Erdgas
Besprechung/Interview
Chemische Forschung
Druckausgleich
Öl
Chemische Verbindungen
Computeranimation
Edelstein
Mannose
Körpertemperatur
Teer
Öl
Weibliche Tote
Verbrennung <Medizin>
Kohlenlagerstätte
Tiermodell
Potenz <Homöopathie>
Cellulose
Durchfluss
Thorium
Bukett <Wein>
Thermoformen
Körpergewicht
Chemieanlage
Ätiologie
Chemische Verbindungen
Lymphangiomyomatosis
Chemische Energie
Enzymkinetik
Chemische Reaktion
Reaktionsführung
Feuer
Besprechung/Interview
Bukett <Wein>
Puder
Boyle-Mariotte-Gesetz
Computeranimation
Gasphase
Germane
Gekochter Schinken
Thorium
Dosis
Bukett <Wein>
Biskalcitratum
Systemische Therapie <Pharmakologie>
Heißräuchern
Matrix <Biologie>
Fülle <Speise>
Chemische Reaktion
Elektron <Legierung>
Scotch <Getränk>
Wasser
Körpertemperatur
Druckausgleich
Computeranimation
Druckbelastung
Protonierung
Stoffmengenanteil
Destillateur
Chemische Eigenschaft
Körpertemperatur
Nanopartikel
Pharmazie
Systemische Therapie <Pharmakologie>
Höhere Landbauschule
Wursthülle
Potenz <Homöopathie>
Besprechung/Interview
Stoffwechselweg
Bucht
Landwirtschaft
Computeranimation
Aktives Zentrum
Verbrennung
Amine <primär->
Bildungsentropie
Funktionelle Gruppe
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Calcineurin
Mannose
Metallatom
Körpertemperatur
Seltenerdverbindungen
Besprechung/Interview
Molekül
Körpertemperatur
Explosion
Druckausgleich
Computeranimation
Gasphase
Seltenerdverbindungen
Besprechung/Interview
Stoffwechselweg
Homogenes System
Salzsprengung
Valin
Periodate
Computeranimation
Waschmittel
Bleifreies Benzin
Fülle <Speise>
Reaktionsführung
Kohlenstofffaser
Besprechung/Interview
Stoffwechselweg
Reaktionsmechanismus
Tank
Pfropfcopolymerisation
Computeranimation
Edelstein
Toll-like-Rezeptoren
Reaktionsgleichung
Chemische Reaktion
Körpertemperatur
Mannose
Kettenlänge <Makromolekül>
Öl
Octane
Containment <Gentechnologie>
Weibliche Tote
Sauerstoffverbindungen
Potenz <Homöopathie>
Molekulargewichtsbestimmung
Oktanzahl
Wursthülle
Besprechung/Interview
Kaugummi
Brennbarkeit
Reaktionsmechanismus
Bildungsenthalpie
Computeranimation
Edelstein
Aktives Zentrum
Altern
Ionenpumpe
Wasserfall
Heptane
Elektronegativität
Resistenz
Systemische Therapie <Pharmakologie>
Bleifreies Benzin
Heptane
Fülle <Speise>
Reaktionsführung
Detonation
Stoffwechselweg
Gangart <Erzlagerstätte>
Progeria adultorum
Elektronische Zigarette
Chemische Reaktion
Thorium
Oktanzahl
Kettenlänge <Makromolekül>
Octane
Katalysator
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Progeria adultorum
Oktanzahl
Besprechung/Interview
Bildungsenthalpie
Computeranimation
Biodiesel
Zündung
Reglersubstanz
Fülle <Speise>
Potenz <Homöopathie>
Ethanol
Elektronische Zigarette
Methanol
Bewegung
Thorium
Detonation
Schaumwein
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Emissionsspektrum
Oktanzahl
Octane
Ethanol
Resistenz
Octane
Biodiesel
Biologisches Material
Potenz <Homöopathie>
Emissionsspektrum
Potenz <Homöopathie>
Calciumhydroxid
Besprechung/Interview
Graphiteinlagerungsverbindungen
Druckausgleich
Computeranimation
Gasphase
Dieselkraftstoff
Bleifreies Benzin
Körpertemperatur
Advanced glycosylation end products
Biodiesel
Auftauen
Potenz <Homöopathie>
Thorium
Potenz <Homöopathie>
Besprechung/Interview
Computeranimation
Zulauf <Verfahrenstechnik>
Tandem-Reaktion
Potenz <Homöopathie>
Wildbach
Potenz <Homöopathie>
Besprechung/Interview
Atom
Computeranimation
Eisfläche
Azokupplung
Primärelement
Formulierung <Technische Chemie>
Potenz <Homöopathie>
Besprechung/Interview
Chemiefaser
Wasser
Systemische Therapie <Pharmakologie>
Chemischer Prozess
Computeranimation
Formulierung <Technische Chemie>
Rost <Feuerung>
Besprechung/Interview
Reibung
Systemische Therapie <Pharmakologie>
Atom
Computeranimation
Reglersubstanz
Rost <Feuerung>
Thorium
Körpertemperatur
Reibung
Abbruchreaktion
Besprechung/Interview
Kaugummi
Reibung
Computeranimation
Druckbelastung
Herzfrequenzvariabilität
Wursthülle
Körpertemperatur
Diamantähnlicher Kohlenstoff
Potenz <Homöopathie>
Mannose
Besprechung/Interview
Stausee
Boyle-Mariotte-Gesetz
Druckausgleich
Computeranimation
Gap junction
Abfüllverfahren
Potenz <Homöopathie>
Cellulose
Besprechung/Interview
Chemischer Prozess
Kochsalz
Computeranimation
Aktives Zentrum
Elektronische Zigarette
Bleichen
Watt
Indium
Explosivität
Gezeitenstrom
Gärungstechnologie
Gezeitenstrom
Explosion
Systemische Therapie <Pharmakologie>
Chemischer Prozess
Reglersubstanz
Potenz <Homöopathie>
Primärelement
Emissionsspektrum
Potenz <Homöopathie>
Besprechung/Interview
Chemischer Prozess
Explosivität
Gezeitenstrom
Computeranimation
Heißräuchern
Biodiesel
Besprechung/Interview
Setzen <Verfahrenstechnik>
Tau-Protein
Computeranimation
Druckbelastung
Altern
Elektronische Zigarette
Rost <Feuerung>
Thorium
Längsprofil
Körpertemperatur
Querprofil
Körpergewicht
Querprofil
Besprechung/Interview
Wasser
Druckausgleich
Lammfleisch
Computeranimation
Druckbelastung
Altern
Biskalcitratum
Querprofil
Körpergewicht
Erstarrung
Besprechung/Interview
Öl
Mas <Biochemie>
Vulkanisation
Computeranimation
Erdrutsch
Druckbelastung
Altern
Potenz <Homöopathie>
Single electron transfer
Single electron transfer
Druckausgleich
Containment <Gentechnologie>
Atom
Computeranimation
Mischgut
Potenz <Homöopathie>
Besprechung/Interview
Stausee
Tank
Druckausgleich
Computeranimation
Mannose
Tank
Biskalcitratum
Arzneimittel
Zunderbeständigkeit
Systemische Therapie <Pharmakologie>
Advanced glycosylation end products
Thorium
Potenz <Homöopathie>
Besprechung/Interview
Quellgebiet

Metadaten

Formale Metadaten

Titel Thermochemistry: Work, Heat, & First Law of Thermodynamics
Serientitel Chemistry 1B: General Chemistry
Teil 09
Anzahl der Teile 18
Autor Shaka, A.J.
Lizenz CC-Namensnennung - Weitergabe unter gleichen Bedingungen 3.0 Unported:
Sie dürfen das Werk bzw. den Inhalt zu jedem legalen und nicht-kommerziellen Zweck nutzen, verändern und in unveränderter oder veränderter Form vervielfältigen, verbreiten und öffentlich zugänglich machen, sofern Sie den Namen des Autors/Rechteinhabers in der von ihm festgelegten Weise nennen und das Werk bzw. diesen Inhalt auch in veränderter Form nur unter den Bedingungen dieser Lizenz weitergeben.
DOI 10.5446/19438
Herausgeber University of California Irvine (UCI)
Erscheinungsjahr 2012
Sprache Englisch

Inhaltliche Metadaten

Fachgebiet Chemie
Abstract UCI Chem 1B General Chemistry (Spring 2012) Lec 09. General Chemistry -- Thermochemistry: Work, Heat, and the First Law of Thermodynamics -- Instructor: A.J. Shaka. Ph.D. Description: UCI Chem 1B is the second quarter of General Chemistry and covers the following topics: properties of gases, liquids, solids; changes of state; properties of solutions; stoichiometry; thermochemistry; and thermodynamics.

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