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Electrochemical Gradient of Cell Membrane.txt | R is a constant. Since this is a neuron cell, it's by temperature. So 37 degrees Celsius. 37 plus 273 is 310. Now, let's see. R is a constant. |
Electrochemical Gradient of Cell Membrane.txt | 37 plus 273 is 310. Now, let's see. R is a constant. F is a constant. N is the number of electrons. In our case, we have 1 mol of electron on this side and on this side. |
Electrochemical Gradient of Cell Membrane.txt | F is a constant. N is the number of electrons. In our case, we have 1 mol of electron on this side and on this side. So n is one. Now, Q, we said, is the concentration in the anode over the concentration in the cathode? So 0.018 molar over zero point 150 molar. |
Electrochemical Gradient of Cell Membrane.txt | So n is one. Now, Q, we said, is the concentration in the anode over the concentration in the cathode? So 0.018 molar over zero point 150 molar. The amp cancel and we get this guy here. Now we plug this into the calculator. We get a negative number and there's a negative on the outside. |
Electrochemical Gradient of Cell Membrane.txt | The amp cancel and we get this guy here. Now we plug this into the calculator. We get a negative number and there's a negative on the outside. So the negatives cancel. And this is our final answer. Now, once again, I want to really talk about what this guy means, because this guy is important. |
Electrochemical Gradient of Cell Membrane.txt | So the negatives cancel. And this is our final answer. Now, once again, I want to really talk about what this guy means, because this guy is important. This is what is achieved at Equilibrium, right? This means that when equilibrium is achieved, the chemical gradient or the concentration gradient equals the electrical gradient. So their rates are equal. |
Electrochemical Gradient of Cell Membrane.txt | This is what is achieved at Equilibrium, right? This means that when equilibrium is achieved, the chemical gradient or the concentration gradient equals the electrical gradient. So their rates are equal. And this is exactly what it is. So our concentration gradient is zero point 57 volts. But our electrical gradient is negative. |
Electrochemical Gradient of Cell Membrane.txt | And this is exactly what it is. So our concentration gradient is zero point 57 volts. But our electrical gradient is negative. Zero point 57. Remember? Because they're reversed. |
Drawing Lewis Structures Example #2.txt | Now, in this lecture, I'd like to continue our discussion on Lewis dot structures. Now, before, we only spoke about neutral species or neutral molecules. Now we're going to draw Lewis dot structures for charged species or charged molecules. So let's begin with A. In a, we have an oh or a hydroxide molecule that has a negative one charge on the oxygen. Now, that negative one charge on the oxygen simply means that oxygen has one more electron than it does in its neutral state. |
Drawing Lewis Structures Example #2.txt | So let's begin with A. In a, we have an oh or a hydroxide molecule that has a negative one charge on the oxygen. Now, that negative one charge on the oxygen simply means that oxygen has one more electron than it does in its neutral state. In other words, in its neutral state, oxygen has eight electrons and eight protons. Now, a charge negative one oxygen molecule has eight protons, but now it has nine electrons. So let's draw our electron configuration for oxygen. |
Drawing Lewis Structures Example #2.txt | In other words, in its neutral state, oxygen has eight electrons and eight protons. Now, a charge negative one oxygen molecule has eight protons, but now it has nine electrons. So let's draw our electron configuration for oxygen. So two electrons go into the one s, two electrons go into the two s, and five electrons go into the two p. Now, H stays the same because H is neutral. And so we place one electron into our one s orbital. So let's begin by first counting the total amount of balanced electrons that we have. |
Drawing Lewis Structures Example #2.txt | So two electrons go into the one s, two electrons go into the two s, and five electrons go into the two p. Now, H stays the same because H is neutral. And so we place one electron into our one s orbital. So let's begin by first counting the total amount of balanced electrons that we have. Remember, balanced electrons are those electrons found in the outermost energy shell. For oxygen, that happens to be the N equals two shell. So two plus five equals seven. |
Drawing Lewis Structures Example #2.txt | Remember, balanced electrons are those electrons found in the outermost energy shell. For oxygen, that happens to be the N equals two shell. So two plus five equals seven. So seven balance electrons for o, and we have one electron in the balanced electron of one s for H. So we have all together eight electrons, eight balanced electrons that we will have to place around our atoms. So let's begin by placing our oxygen and H adjacent to one another. So we have eight electrons. |
Drawing Lewis Structures Example #2.txt | So seven balance electrons for o, and we have one electron in the balanced electron of one s for H. So we have all together eight electrons, eight balanced electrons that we will have to place around our atoms. So let's begin by placing our oxygen and H adjacent to one another. So we have eight electrons. Let's begin by drawing a sigma oracovalent bond between oxygen and nitrogen. So once we draw this line, that basically means that one electron is being donated by H and one electron is being donated by o. Now, this means that all the orbitals, meaning this one s orbital, is completely filled for H. Because before, when H is by itself, it has one electron in its one s shell. |
Drawing Lewis Structures Example #2.txt | Let's begin by drawing a sigma oracovalent bond between oxygen and nitrogen. So once we draw this line, that basically means that one electron is being donated by H and one electron is being donated by o. Now, this means that all the orbitals, meaning this one s orbital, is completely filled for H. Because before, when H is by itself, it has one electron in its one s shell. But now this electron is being shared. So we have two electrons in the one s shell. And that means all electrons or all the orbitals of the age are completely filled. |
Drawing Lewis Structures Example #2.txt | But now this electron is being shared. So we have two electrons in the one s shell. And that means all electrons or all the orbitals of the age are completely filled. So we can't place any more electrons around our age. How about oxygen? Well, oxygen has more orbitals, right? |
Drawing Lewis Structures Example #2.txt | So we can't place any more electrons around our age. How about oxygen? Well, oxygen has more orbitals, right? When this orbital is still it has three more orbitals. So that means we can place the remaining six valve electrons into or around our oxygen. So we place a pair here. |
Drawing Lewis Structures Example #2.txt | When this orbital is still it has three more orbitals. So that means we can place the remaining six valve electrons into or around our oxygen. So we place a pair here. A place we place a pair here, and we place a pair here. Now, notice in its mutual state, oxygen has six electrons. But because we have one plus one plus one plus one plus one plus one plus one, this gives us six or seven electrons. |
Drawing Lewis Structures Example #2.txt | A place we place a pair here, and we place a pair here. Now, notice in its mutual state, oxygen has six electrons. But because we have one plus one plus one plus one plus one plus one plus one, this gives us six or seven electrons. That means we're going to have a negative one charge on the oxygen. So this concludes our Lewis dot structure. Just to make sure, let's make sure we have the right amount of electrons. |
Drawing Lewis Structures Example #2.txt | That means we're going to have a negative one charge on the oxygen. So this concludes our Lewis dot structure. Just to make sure, let's make sure we have the right amount of electrons. So our electron counts, we have two electrons in the bonding or covalent bond, and six non bonding electrons surrounding our oxygen. So two plus six is eight. We begin with eight balance electrons. |
Drawing Lewis Structures Example #2.txt | So our electron counts, we have two electrons in the bonding or covalent bond, and six non bonding electrons surrounding our oxygen. So two plus six is eight. We begin with eight balance electrons. We end with eight balance electrons. Oxygen has a negative one charge. So this concludes part a. |
Drawing Lewis Structures Example #2.txt | We end with eight balance electrons. Oxygen has a negative one charge. So this concludes part a. Let's move to part b. In part B, we have this BH four molecule. Now b is boron. |
Drawing Lewis Structures Example #2.txt | Let's move to part b. In part B, we have this BH four molecule. Now b is boron. Normally, boron has five protons and five electrons in its neutral state. But because this has a negative one charge, it has one more electron. So that means it has a total of six electrons and five protons. |
Drawing Lewis Structures Example #2.txt | Normally, boron has five protons and five electrons in its neutral state. But because this has a negative one charge, it has one more electron. So that means it has a total of six electrons and five protons. So two going to the one s, two going to the two s, and two going to the two p. H still has that one electron in the one s because it's neutral. Now, notice, however, now we have four h atoms. And that means when we're counting our balanced electrons, we have not one electron from h, but four electrons from h. So four times one. |
Drawing Lewis Structures Example #2.txt | So two going to the one s, two going to the two s, and two going to the two p. H still has that one electron in the one s because it's neutral. Now, notice, however, now we have four h atoms. And that means when we're counting our balanced electrons, we have not one electron from h, but four electrons from h. So four times one. So we have four electrons coming from h, and two plus two four electrons coming from our boron. So altogether, we have eight balanced electrons. So once again, we place our b in the middle, our central atom, and we place our h atoms around our b atom. |
Drawing Lewis Structures Example #2.txt | So we have four electrons coming from h, and two plus two four electrons coming from our boron. So altogether, we have eight balanced electrons. So once again, we place our b in the middle, our central atom, and we place our h atoms around our b atom. So we begin by first creating sigma or covalent bonds. So we connect our b's and HS, and now we have four covalent bonds. So let's count how many electrons we have. |
Drawing Lewis Structures Example #2.txt | So we begin by first creating sigma or covalent bonds. So we connect our b's and HS, and now we have four covalent bonds. So let's count how many electrons we have. So we begin with eight. And now we have 1234-5678. So we have completely used up all our balance electrons, and that means that this is our lewis structure. |
Drawing Lewis Structures Example #2.txt | So we begin with eight. And now we have 1234-5678. So we have completely used up all our balance electrons, and that means that this is our lewis structure. Now, normally, boron could form three bonds, so it has three electrons. But in this case, it has 12341 more electron than in its neutral state. And that means that it has a negative one charge. |
Drawing Lewis Structures Example #2.txt | Now, normally, boron could form three bonds, so it has three electrons. But in this case, it has 12341 more electron than in its neutral state. And that means that it has a negative one charge. So let's do our electron count. We have eight bonding electrons, right? 2468 and zero non bonding. |
Drawing Lewis Structures Example #2.txt | So let's do our electron count. We have eight bonding electrons, right? 2468 and zero non bonding. So we have a net of eight electrons. And that concludes our picture for b. Let's jump to part C. In part C, we have this ammonium atom, or NH, four positive. |
Drawing Lewis Structures Example #2.txt | So we have a net of eight electrons. And that concludes our picture for b. Let's jump to part C. In part C, we have this ammonium atom, or NH, four positive. That means nitrogen has one less electron than it does in its neutral state. So let's draw our electron configuration. For n.
One or two electrons go into the two s, two electrons go to the two or two electrons going to the one s, two electrons go to the two s, and two electrons go into the two p now, normally, in a neutral atom, we would have three electrons going to the two P. But because it has a plus one, that means it has one more proton in an electron. |
Drawing Lewis Structures Example #2.txt | That means nitrogen has one less electron than it does in its neutral state. So let's draw our electron configuration. For n.
One or two electrons go into the two s, two electrons go to the two or two electrons going to the one s, two electrons go to the two s, and two electrons go into the two p now, normally, in a neutral atom, we would have three electrons going to the two P. But because it has a plus one, that means it has one more proton in an electron. So it has only two electrons in the two p.
H, once again, is neutral, so it has one electron in the one s orbital. Once again, we count our balanced electrons. We have two and two. |
Drawing Lewis Structures Example #2.txt | So it has only two electrons in the two p.
H, once again, is neutral, so it has one electron in the one s orbital. Once again, we count our balanced electrons. We have two and two. So four electrons coming from n, and one times four. So eight balanced electrons altogether. So once again, the same story. |
Drawing Lewis Structures Example #2.txt | So four electrons coming from n, and one times four. So eight balanced electrons altogether. So once again, the same story. We draw out our N, that central atom in the middle. We draw our four HS around and we connect our HS and NS. So notice we have two, four, six and eight. |
Drawing Lewis Structures Example #2.txt | We draw out our N, that central atom in the middle. We draw our four HS around and we connect our HS and NS. So notice we have two, four, six and eight. So we have a total of eight balanced electrons. So we have used up our balanced electrons. And this must be the electron configuration for NH four. |
Drawing Lewis Structures Example #2.txt | So we have a total of eight balanced electrons. So we have used up our balanced electrons. And this must be the electron configuration for NH four. Notice that once again, n is used to having five electrons. Here. It has four electrons. |
Drawing Lewis Structures Example #2.txt | Notice that once again, n is used to having five electrons. Here. It has four electrons. 1234 So it has a plus one charge on the N, and these HS are neutral. So a net charge of plus one. |
Drawing Lewis Structures Example #2.txt | 1234 So it has a plus one charge on the N, and these HS are neutral. So a net charge of plus one. Once again our electron count. Eight electrons coming from the bonding orbitals. Or the bonding electrons. |
Drawing Lewis Structures Example #2.txt | Once again our electron count. Eight electrons coming from the bonding orbitals. Or the bonding electrons. And we have zero non bonding electrons, just like we had in this picture here. So let's go to the last one. Part D.
In Part D, we have NH Two with a minus one. |
Drawing Lewis Structures Example #2.txt | And we have zero non bonding electrons, just like we had in this picture here. So let's go to the last one. Part D.
In Part D, we have NH Two with a minus one. So right here we had a plus one and here we have a minus one on the end. That means it will have one more electron than a dot in its neutral state. So instead of having three electrons in its two p it's going to have four electrons in its two p orbital. |
Drawing Lewis Structures Example #2.txt | So right here we had a plus one and here we have a minus one on the end. That means it will have one more electron than a dot in its neutral state. So instead of having three electrons in its two p it's going to have four electrons in its two p orbital. So two going to the one S, two going to the two S, and four going to the two P. H is once again neutral. It has one electron in the one s. So we have two h atoms. So two times one, we have two electrons balance electrons coming from h and two plus four six electrons coming from n.
So altogether, once again we have eight balance electrons. |
Drawing Lewis Structures Example #2.txt | So two going to the one S, two going to the two S, and four going to the two P. H is once again neutral. It has one electron in the one s. So we have two h atoms. So two times one, we have two electrons balance electrons coming from h and two plus four six electrons coming from n.
So altogether, once again we have eight balance electrons. So once again we begin our drawing by writing or drawing n in the middle of the central atom and h is adjacent to it. So we connect our atoms, and now we are left with four balance electrons. Because we begin with eight balance electrons. |
Drawing Lewis Structures Example #2.txt | So once again we begin our drawing by writing or drawing n in the middle of the central atom and h is adjacent to it. So we connect our atoms, and now we are left with four balance electrons. Because we begin with eight balance electrons. We use up 12348. Minus four is four. And because these orbitals are filled, we are left with filling. |
Drawing Lewis Structures Example #2.txt | We use up 12348. Minus four is four. And because these orbitals are filled, we are left with filling. The N orbitals. So we basically put two here. We place two here and we conclude our drawing. |
Drawing Lewis Structures Example #2.txt | The N orbitals. So we basically put two here. We place two here and we conclude our drawing. Because now we have 1234-5678 balance electrons. We have four bonding and four non bonding electrons. And because nitrogen is normally used to having five electrons, and in this case it has 123-4456, this end will have a negative one charge. |
Root Mean Square Velocity .txt | Now let's look at two sets of values. In my first set I have 21012, in my second set I have negative two, two negative 1012. I want to take the average of, or find the average of this set. And this set, well, I add up all my values, divide them by five and get six over five. And the same thing for this guy, negative one, negative one, negative two minus negative one plus zero, plus one plus two divided by five. Well, these guys cancel and I get zero. |
Root Mean Square Velocity .txt | And this set, well, I add up all my values, divide them by five and get six over five. And the same thing for this guy, negative one, negative one, negative two minus negative one plus zero, plus one plus two divided by five. Well, these guys cancel and I get zero. Now look, in this set all my numbers have the same magnitude as these guys. But in this set, these first two numbers have the same magnitude as these first two numbers, but different signs. And that's why my average is zero. |
Root Mean Square Velocity .txt | Now look, in this set all my numbers have the same magnitude as these guys. But in this set, these first two numbers have the same magnitude as these first two numbers, but different signs. And that's why my average is zero. So in some cases, this type of average won't make sense. Now, from a fitness perspective, let's look at moving cars. Suppose a car is traveling in this direction at 60. |
Root Mean Square Velocity .txt | So in some cases, this type of average won't make sense. Now, from a fitness perspective, let's look at moving cars. Suppose a car is traveling in this direction at 60. Suppose in this direction is a positive direction. Now suppose another car is also traveling 60 mph, but in the other direction, so it's negative 60, where 60 is our magnitude and direction is our negative sign. So if someone asks you what is the average of the first two cars, from a physics perspective you will say 60 mph. |
Root Mean Square Velocity .txt | Suppose in this direction is a positive direction. Now suppose another car is also traveling 60 mph, but in the other direction, so it's negative 60, where 60 is our magnitude and direction is our negative sign. So if someone asks you what is the average of the first two cars, from a physics perspective you will say 60 mph. Because if one car is going 60 and the other car is going 60, then the average must be 60. Well, if you use the formula to find the average from a mathematics point of view, you will see that it's 60 plus -60, gives you zero divided by two, which is zero. So sometimes from a mathematics point of view, taking the average in the same way that you did here doesn't make sense. |
Root Mean Square Velocity .txt | Because if one car is going 60 and the other car is going 60, then the average must be 60. Well, if you use the formula to find the average from a mathematics point of view, you will see that it's 60 plus -60, gives you zero divided by two, which is zero. So sometimes from a mathematics point of view, taking the average in the same way that you did here doesn't make sense. Because in the real world, if you have two cars traveling at some speed and you take their average, how can the average be zero? So that's where the root mean square formula comes from. What this formula does is it takes away these negatives and gives you the value of this type of average without the negatives. |
Root Mean Square Velocity .txt | Because in the real world, if you have two cars traveling at some speed and you take their average, how can the average be zero? So that's where the root mean square formula comes from. What this formula does is it takes away these negatives and gives you the value of this type of average without the negatives. So let's look at the formula. VRS is equal to, you take the squares of every single velocity or every single value and then you divide that by n. So almost the same thing as you did here, except you square every value. The reason you square every value is because a square will take away that negative sign and then you divide by n and you take the square root of that. |
Root Mean Square Velocity .txt | So let's look at the formula. VRS is equal to, you take the squares of every single velocity or every single value and then you divide that by n. So almost the same thing as you did here, except you square every value. The reason you square every value is because a square will take away that negative sign and then you divide by n and you take the square root of that. So this will always give you a positive value. So let's take this example and let's use these two values to find our average. So BRMs is equal to 60 mph squared plus negative 60 mph squared. |
Root Mean Square Velocity .txt | So this will always give you a positive value. So let's take this example and let's use these two values to find our average. So BRMs is equal to 60 mph squared plus negative 60 mph squared. This gives you 3600 plus negative canceled. So 3600 gives you 7200 divided by two and square root, that gives you 60 mph. So you see, once again, that the purpose of the route means square is to take away those negative signs and just give you the magnitude. |
Root Mean Square Velocity .txt | This gives you 3600 plus negative canceled. So 3600 gives you 7200 divided by two and square root, that gives you 60 mph. So you see, once again, that the purpose of the route means square is to take away those negative signs and just give you the magnitude. And this becomes useful when you're talking about velocities. Because if a molecule is traveling with one velocity this way and another molecule is traveling with the same velocity but the direction the other way, you want to take those averages and you want those averages to give you a positive value, not zero. That's exactly why you use root mean square velocity. |
Root Mean Square Velocity .txt | And this becomes useful when you're talking about velocities. Because if a molecule is traveling with one velocity this way and another molecule is traveling with the same velocity but the direction the other way, you want to take those averages and you want those averages to give you a positive value, not zero. That's exactly why you use root mean square velocity. So you see that this guy gives you 60 just like it would from a logical physics perspective. From a pure mathematical perspective, it gives you zero if you use the formula. Now, one last thing I want to mention is that this definition of velocity is not actually correct. |
Root Mean Square Velocity .txt | So you see that this guy gives you 60 just like it would from a logical physics perspective. From a pure mathematical perspective, it gives you zero if you use the formula. Now, one last thing I want to mention is that this definition of velocity is not actually correct. Because remember, velocity is a vector. That means it has both magnitude and direction. While speed is a scaling, it only has magnitude. |
Root Mean Square Velocity .txt | Because remember, velocity is a vector. That means it has both magnitude and direction. While speed is a scaling, it only has magnitude. Now, this velocity only has magnitude. It doesn't have direction. Because when we take the square root, we can't get a negative, so we always get positive. |
First Law of Thermodynamics .txt | So today we're going to talk about the first law of thermodynamics, the second law of thermodynamics and the heat engine. So the first law of thermodynamics is an extension from the law of conservation of energy which states that energy cannot be created, it cannot be destroyed, it must be transformed from one form to another. Now, when we talk about the first law of thermodynamics, we basically, basically talk about closed systems. Now, aside from closed systems, they're open systems as well as isolated systems. Within a closed system, matter or mass is not allowed to exchange. The mass remains constant within the system. |
First Law of Thermodynamics .txt | Now, aside from closed systems, they're open systems as well as isolated systems. Within a closed system, matter or mass is not allowed to exchange. The mass remains constant within the system. What is allowed to exchange, however, is energy. So energy flows into the system or it can flow out of the system. In an isolated system, mass and energy is not allowed to flow anywhere. |
First Law of Thermodynamics .txt | What is allowed to exchange, however, is energy. So energy flows into the system or it can flow out of the system. In an isolated system, mass and energy is not allowed to flow anywhere. So everything remains constant. In an open system, both matter and energy is allowed to exchange. Okay? |
First Law of Thermodynamics .txt | So everything remains constant. In an open system, both matter and energy is allowed to exchange. Okay? Now when we talk about the transfer of energy, remember that there are only two types of transfer of energy work and heat. Now heat can be subdivided into three categories convection, conduction and radiation. When we talk about chemical work, we talk about this type of work pressure times change in volume. |
First Law of Thermodynamics .txt | Now when we talk about the transfer of energy, remember that there are only two types of transfer of energy work and heat. Now heat can be subdivided into three categories convection, conduction and radiation. When we talk about chemical work, we talk about this type of work pressure times change in volume. And when pressure remains constant, we use this equation. When pressure isn't constant, we use calculus and integrate from the initial to the final. Now this law can be summarized in this equation. |
First Law of Thermodynamics .txt | And when pressure remains constant, we use this equation. When pressure isn't constant, we use calculus and integrate from the initial to the final. Now this law can be summarized in this equation. Okay? This law basically translates into this equation. And what this equation states is pretty simple. |
First Law of Thermodynamics .txt | Okay? This law basically translates into this equation. And what this equation states is pretty simple. All it states is that the energy transfer or energy flow into a system is equal to the heat flow into the system plus the work done on the system. What it basically says is that a transfer of energy amounts to two types of transfers. Transfers due to heat or transfers due to work. |
First Law of Thermodynamics .txt | All it states is that the energy transfer or energy flow into a system is equal to the heat flow into the system plus the work done on the system. What it basically says is that a transfer of energy amounts to two types of transfers. Transfers due to heat or transfers due to work. Okay, no other transfer of energy exists. So let's see what heat engines are. Heat engines are basically systems or mechanisms that convert one form of energy into a second form of energy, namely heat into work. |
First Law of Thermodynamics .txt | Okay, no other transfer of energy exists. So let's see what heat engines are. Heat engines are basically systems or mechanisms that convert one form of energy into a second form of energy, namely heat into work. And this occurs under constant temperature. So let's see what the layout of a heat engine is. A heat engine is composed of a long cylindrical tube that contains molecules inside this area and that contains a movable piston controlled by an outside force, maybe your hand that's moving it up or down. |
First Law of Thermodynamics .txt | And this occurs under constant temperature. So let's see what the layout of a heat engine is. A heat engine is composed of a long cylindrical tube that contains molecules inside this area and that contains a movable piston controlled by an outside force, maybe your hand that's moving it up or down. It also contains a hot body connected to the bottom. This hot body is important in conduction because remember, conduction requires for physical contact between two systems. And conduction allows heat transfer or energy transfer from a hot object to a cold object. |
First Law of Thermodynamics .txt | It also contains a hot body connected to the bottom. This hot body is important in conduction because remember, conduction requires for physical contact between two systems. And conduction allows heat transfer or energy transfer from a hot object to a cold object. So let's see what the result is of constant pressure. From this formula we see that kinetic energy is related to KB, which is a constant and number of particles and T temperature. Now, the number of particles remains constant because this is a closed system. |
First Law of Thermodynamics .txt | So let's see what the result is of constant pressure. From this formula we see that kinetic energy is related to KB, which is a constant and number of particles and T temperature. Now, the number of particles remains constant because this is a closed system. Remember, a closed system is a system in which the mass or matter or the number of particles remains constant. So n remains constant. These guys remain constant, and temperature remains constant. |
First Law of Thermodynamics .txt | Remember, a closed system is a system in which the mass or matter or the number of particles remains constant. So n remains constant. These guys remain constant, and temperature remains constant. So that means kinetic energy also must remain constant. Okay, so what's the result? Remember, normally, when there's a transfer of energy, the energy is transferred into increasing the kinetic energy. |
First Law of Thermodynamics .txt | So that means kinetic energy also must remain constant. Okay, so what's the result? Remember, normally, when there's a transfer of energy, the energy is transferred into increasing the kinetic energy. But in this situation, there is no increase in kinetic energy. So the question remains, where does this energy transfer go into if it doesn't go into the kinetic energy? Okay, the answer lies in this equation. |
First Law of Thermodynamics .txt | But in this situation, there is no increase in kinetic energy. So the question remains, where does this energy transfer go into if it doesn't go into the kinetic energy? Okay, the answer lies in this equation. We see that by the ideal Gas Law, PV, or pressure times volume equals number of moles times the constant times the temperature in Kelvin. Okay? So this guy remains constant because the temperature remains constant. |
First Law of Thermodynamics .txt | We see that by the ideal Gas Law, PV, or pressure times volume equals number of moles times the constant times the temperature in Kelvin. Okay? So this guy remains constant because the temperature remains constant. And these guys are constants. This is constant because this is a closed system. So this must mean that the energy transfer must go into increasing the volume or expanding it. |
First Law of Thermodynamics .txt | And these guys are constants. This is constant because this is a closed system. So this must mean that the energy transfer must go into increasing the volume or expanding it. And the expansion creates a larger D or a larger volume. And because this guy is constant, this must be constant. So an increase in D must mean a decrease in P. A decrease in P will decrease. |
First Law of Thermodynamics .txt | And the expansion creates a larger D or a larger volume. And because this guy is constant, this must be constant. So an increase in D must mean a decrease in P. A decrease in P will decrease. Obviously, this P, and look, p, or pressure, is equal to force comes area. Area remains constant, because if you take the cross sectional area of this cylinder, it doesn't change as the piston moves up or down. So if this guy is constant and this guy is decreasing, the pressure is decreasing, then the force must also decrease. |
First Law of Thermodynamics .txt | Obviously, this P, and look, p, or pressure, is equal to force comes area. Area remains constant, because if you take the cross sectional area of this cylinder, it doesn't change as the piston moves up or down. So if this guy is constant and this guy is decreasing, the pressure is decreasing, then the force must also decrease. So we see that in a heat engine, when the piston is moving, the force is changing, and so is pressure, and so is volume, but temperature remains the same. Okay, so what this basically means, or what this basically implies, is that heat must be converted to work, and all the heat must be converted to work. But that's actually not true, and only about 10% to 20% normally is converted to work. |
First Law of Thermodynamics .txt | So we see that in a heat engine, when the piston is moving, the force is changing, and so is pressure, and so is volume, but temperature remains the same. Okay, so what this basically means, or what this basically implies, is that heat must be converted to work, and all the heat must be converted to work. But that's actually not true, and only about 10% to 20% normally is converted to work. Okay, and let's see why. Well, let's go back here. When the energy is transferred into this system, this system, the volume increases because the piston starts moving this way, and it continues moving this way until when? |
First Law of Thermodynamics .txt | Okay, and let's see why. Well, let's go back here. When the energy is transferred into this system, this system, the volume increases because the piston starts moving this way, and it continues moving this way until when? Until it hits this limit here, because the cylinder eventually ends when it reaches this place. You have this picture here, okay? And now what happens? |
First Law of Thermodynamics .txt | Until it hits this limit here, because the cylinder eventually ends when it reaches this place. You have this picture here, okay? And now what happens? Now we need to somehow move this piston back to its original location so the process could repeat. So this is a cyclic process, right? We want energy to go into here to move the piston this way. |
First Law of Thermodynamics .txt | Now we need to somehow move this piston back to its original location so the process could repeat. So this is a cyclic process, right? We want energy to go into here to move the piston this way. Then we want to move the piston back this way, and this to continues, okay? Indefinitely. But let's see what happens here. |
First Law of Thermodynamics .txt | Then we want to move the piston back this way, and this to continues, okay? Indefinitely. But let's see what happens here. When we have a force and we start pushing with the force this way, what happens to the kinetic energy or the temperature of the particles within this system? Well, when you move this way, pressure increases, volume decreases, and the particles get closer together. They start banging against each other more violently, more frequently. |
First Law of Thermodynamics .txt | When we have a force and we start pushing with the force this way, what happens to the kinetic energy or the temperature of the particles within this system? Well, when you move this way, pressure increases, volume decreases, and the particles get closer together. They start banging against each other more violently, more frequently. This, in turn, increases temperature, which in turn increases kinetic energy, but we saw that we want to have constant temperature. Okay, so what does this mean? While this increase in temperature means that there is an increase in pressure and there's an increase in the force, so not the force that we require or the net force that we require to move from this point to this point is greater than the force required to move from this point to this point. |
First Law of Thermodynamics .txt | This, in turn, increases temperature, which in turn increases kinetic energy, but we saw that we want to have constant temperature. Okay, so what does this mean? While this increase in temperature means that there is an increase in pressure and there's an increase in the force, so not the force that we require or the net force that we require to move from this point to this point is greater than the force required to move from this point to this point. So the work that's required to move depiction from this position to this position is less than the work required to move from this position to this position. And that's not something we want. We want to be efficient, and that's not very efficient. |
First Law of Thermodynamics .txt | So the work that's required to move depiction from this position to this position is less than the work required to move from this position to this position. And that's not something we want. We want to be efficient, and that's not very efficient. So how do we fix this system? Well, we fix the system by adding another object to the heat engine, something called a cold body. We saw that we had a hot body for the specific purpose of conduction. |
First Law of Thermodynamics .txt | So how do we fix this system? Well, we fix the system by adding another object to the heat engine, something called a cold body. We saw that we had a hot body for the specific purpose of conduction. Well, now we have a cold body that also is specific for conduction. In other words, when this piston moves this way, there's an increase in temperature. And the increase in temperature causes energy to transfer via conduction from this place to this place. |
First Law of Thermodynamics .txt | Well, now we have a cold body that also is specific for conduction. In other words, when this piston moves this way, there's an increase in temperature. And the increase in temperature causes energy to transfer via conduction from this place to this place. And this makes the temperature stay constant. Okay, so the final outcome is that a heat engine needs to look like this. A heat engine needs to have a hot body, a cold body, a cylindrical tube, as well as a piston that's controlled by some outside force. |
Cell voltage and Gibbs free energy .txt | A positive cell voltage indicates that our reaction within our electrochemical cell is product favorite, so it's spontaneous. Likewise, a negative cell voltage indicates a reactant favorite reaction. Recall that Gibbs free energy builds a relationship between entropy and entropy, and it also dictates whether a reaction is product favorite or reactant favorite. So notice that both cell voltage of an electrochemical cell and GIBS free energy dictate whether or not a reaction is product favorite. So therefore, we can imagine that there's some type of relationship between cell voltage and gives free energy. Now, when gives free energy is positive, that means our reaction is reacting favorite. |
Cell voltage and Gibbs free energy .txt | So notice that both cell voltage of an electrochemical cell and GIBS free energy dictate whether or not a reaction is product favorite. So therefore, we can imagine that there's some type of relationship between cell voltage and gives free energy. Now, when gives free energy is positive, that means our reaction is reacting favorite. It's not spontaneous. But when it's negative, the reaction is product favorite. It is spontaneous. |
Cell voltage and Gibbs free energy .txt | It's not spontaneous. But when it's negative, the reaction is product favorite. It is spontaneous. Now, before we actually build a relationship and show how the cell voltage relates to GIBS free energy, let's examine something called electrical work. Now, we already spoke about electrical work when we spoke about electromotive force, but let's revisit this topic because it becomes important. So voltaic cells or electrochemical cells convert chemical energy into electrical potential energy that can be used to do work, for example, para light bulb or para motor. |
Cell voltage and Gibbs free energy .txt | Now, before we actually build a relationship and show how the cell voltage relates to GIBS free energy, let's examine something called electrical work. Now, we already spoke about electrical work when we spoke about electromotive force, but let's revisit this topic because it becomes important. So voltaic cells or electrochemical cells convert chemical energy into electrical potential energy that can be used to do work, for example, para light bulb or para motor. Now, this electrical potential energy is also known as electrical work. And we can express electrical work mathematically by equaling this guy to charge of an object or a system times our cell voltage. So if we're talking about cells and electrochemical cells, our charge refers to all the possible charge in our battery in our chemical cell or electric chemical cells. |
Cell voltage and Gibbs free energy .txt | Now, this electrical potential energy is also known as electrical work. And we can express electrical work mathematically by equaling this guy to charge of an object or a system times our cell voltage. So if we're talking about cells and electrochemical cells, our charge refers to all the possible charge in our battery in our chemical cell or electric chemical cells. Now, recall that a single electron has a charge of 1.622
times ten to negative 19 Coulombs. This is per electron per one electron. But obviously, a single battery, a single electrochemical cell, has many electrons within itself. |
Cell voltage and Gibbs free energy .txt | Now, recall that a single electron has a charge of 1.622
times ten to negative 19 Coulombs. This is per electron per one electron. But obviously, a single battery, a single electrochemical cell, has many electrons within itself. That means we're dealing with a lot of these guys. Now, let's find how much charge is in 1 mol of electrons. Right? |
Cell voltage and Gibbs free energy .txt | That means we're dealing with a lot of these guys. Now, let's find how much charge is in 1 mol of electrons. Right? The way we do it is we use avogadjo's number. Remember, avogadjo's number refers to the number of atoms or electrons found in 1 mol of anything. Now, we're talking about 1 mol of electrons. |
Cell voltage and Gibbs free energy .txt | The way we do it is we use avogadjo's number. Remember, avogadjo's number refers to the number of atoms or electrons found in 1 mol of anything. Now, we're talking about 1 mol of electrons. That means we take this number of electrons and we multiply by our charge per electron. We see that averagadro's number of electrons per mole times 1.622 times ten to the negative 19 kilos per electron, which we got from here. The electrons cancel, and we get our units to be Coulomb per mole. |
Cell voltage and Gibbs free energy .txt | That means we take this number of electrons and we multiply by our charge per electron. We see that averagadro's number of electrons per mole times 1.622 times ten to the negative 19 kilos per electron, which we got from here. The electrons cancel, and we get our units to be Coulomb per mole. So the charge of a single mole of electron electrons is 96,484 Coulombs per mole of electron. So when we have 6.22 times ten to the 23 electrons in our cell, that means our cell has a charge of 96,484 klombs. So we can represent this equation in another way. |
Cell voltage and Gibbs free energy .txt | So the charge of a single mole of electron electrons is 96,484 Coulombs per mole of electron. So when we have 6.22 times ten to the 23 electrons in our cell, that means our cell has a charge of 96,484 klombs. So we can represent this equation in another way. So, this equation electrical work is equal to n, the number of moles times f. Now, f is Faraday's constant. This is known as this number is known as Faraday's constant. And it talks about a charge of one coulomb per mole of electrons. |
Cell voltage and Gibbs free energy .txt | So, this equation electrical work is equal to n, the number of moles times f. Now, f is Faraday's constant. This is known as this number is known as Faraday's constant. And it talks about a charge of one coulomb per mole of electrons. So, once again, f is Faradays constant times our cell voltage. So this n times f is simply charge. It's the same thing. |
Cell voltage and Gibbs free energy .txt | So, once again, f is Faradays constant times our cell voltage. So this n times f is simply charge. It's the same thing. Now, for example, if we have 1 mol in our cell, that means we multiply 1 mol times f.
So 1 mol times this guy gives us the most cancel, and we simply get our charge. So n times f is our charge. Now, this equation becomes important when we build a relationship between our cell voltage and gear spree energy. |
Cell voltage and Gibbs free energy .txt | Now, for example, if we have 1 mol in our cell, that means we multiply 1 mol times f.
So 1 mol times this guy gives us the most cancel, and we simply get our charge. So n times f is our charge. Now, this equation becomes important when we build a relationship between our cell voltage and gear spree energy. So let's see what the relationship is. So, let's finally examine and see what the relationship is between cell voltage and changing gear free energy. Well, we see that changing gear's free energy is equal to negative of electrical work done. |
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