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Work.txt | If you multiply this side by distance, we get pressure times area times distance. But remember, that area times distance is simply the volume. That is, if we go back to our Piston example and the Piston moves a certain distance, say, D, then this area A times distance D will give us this whole volume here or the change in volume. Therefore, pressure times change in volume is equal to work. And that's how we derive this equation, from pressure. Okay? |
Work.txt | Therefore, pressure times change in volume is equal to work. And that's how we derive this equation, from pressure. Okay? And that's what work is in a chemical perspective or from a chemical perspective. Now let's look at a graph of pressure versus volume, when pressure is constant, okay? What we see is pressure is the y axis, the vertical axis. |
Work.txt | And that's what work is in a chemical perspective or from a chemical perspective. Now let's look at a graph of pressure versus volume, when pressure is constant, okay? What we see is pressure is the y axis, the vertical axis. It's constant. So it's the same throughout the entire process. The volume, however, changes. |
Work.txt | It's constant. So it's the same throughout the entire process. The volume, however, changes. It goes from some lower volume to some higher volume. Okay? What the work is, is this. |
Work.txt | It goes from some lower volume to some higher volume. Okay? What the work is, is this. The pressure which is constant. The pressure is the vertical side, this side. So that's pressure times the change in volume v two or V final minus V one, B initial. |
Work.txt | The pressure which is constant. The pressure is the vertical side, this side. So that's pressure times the change in volume v two or V final minus V one, B initial. So this side, this is change in volume. So this side times this side gives us the work. So since this is a rectangle and the area of a rectangle is is side times width, what we see or side times width, what we see is that work is this shade regions here. |
Work.txt | So this side, this is change in volume. So this side times this side gives us the work. So since this is a rectangle and the area of a rectangle is is side times width, what we see or side times width, what we see is that work is this shade regions here. And this is actually work. Pressure times change in volume. Okay? |
Work.txt | And this is actually work. Pressure times change in volume. Okay? Now, if we want to find a work when pressure is in constant, we could still do it. But then we have to use the integral over some area, okay? We could no longer use this equation because this equation assumes that pressure is constant throughout the experiment. |
Internal Energy of Matter .txt | Well, internal energy is the collective energy of all the different types of molecules found within a system. Now, a system can be composed of billions of different molecules. For simplification purposes, we're going to look at a system with only two diatomic oxygen molecules, moles. Now, let's look at the types of energies molecules could have. Well, they can have either kinetic energy or potential energy. Kinetic energy is the energy due to motion, and it could be subdivided into three different types. |
Internal Energy of Matter .txt | Now, let's look at the types of energies molecules could have. Well, they can have either kinetic energy or potential energy. Kinetic energy is the energy due to motion, and it could be subdivided into three different types. Translational energy is the energy due to velocity. Now, when a mass moves with a certain velocity, it carries a certain kinetic energy. And this becomes important in gasses and liquids. |
Internal Energy of Matter .txt | Translational energy is the energy due to velocity. Now, when a mass moves with a certain velocity, it carries a certain kinetic energy. And this becomes important in gasses and liquids. In solids, vibrational energy takes over. In solids, the molecules don't really move too much. They vibrate. |
Internal Energy of Matter .txt | In solids, vibrational energy takes over. In solids, the molecules don't really move too much. They vibrate. And this vibration is created due to repulsion and attraction of protons and electrons. Now, if we look at this diatomic oxygen molecule, we'll see that this is the case. This diatomic oxygen molecule is composed of two nuclei. |
Internal Energy of Matter .txt | And this vibration is created due to repulsion and attraction of protons and electrons. Now, if we look at this diatomic oxygen molecule, we'll see that this is the case. This diatomic oxygen molecule is composed of two nuclei. These two nuclei repel each other because they are positively charged. So they want to move away from each other. But notice that each one has an electron cloud around it. |
Internal Energy of Matter .txt | These two nuclei repel each other because they are positively charged. So they want to move away from each other. But notice that each one has an electron cloud around it. And this guy will attract these guys, and this guy will attract these guys. So this will create motion, a reverse motion. Instead of repulsing, they want to attract, okay? |
Internal Energy of Matter .txt | And this guy will attract these guys, and this guy will attract these guys. So this will create motion, a reverse motion. Instead of repulsing, they want to attract, okay? So this creates repulsion, but they want to attract due to the attraction between this and this and that and that. Okay, so they create this harmonic vibrational force. And this is important in solid, okay, rotational. |
Internal Energy of Matter .txt | So this creates repulsion, but they want to attract due to the attraction between this and this and that and that. Okay, so they create this harmonic vibrational force. And this is important in solid, okay, rotational. The first type of kinetic energy, rotational energy is the energy due to torque. Now, when molecules, for example, the atomic oxygen moves, it moves and rotates. It rotates this way. |
Internal Energy of Matter .txt | The first type of kinetic energy, rotational energy is the energy due to torque. Now, when molecules, for example, the atomic oxygen moves, it moves and rotates. It rotates this way. The same way when you throw a Frisbee, the Frisbee rotates and it moves. And this rotation creates a curved path, okay? And this rotation also creates kinetic energy. |
Internal Energy of Matter .txt | The same way when you throw a Frisbee, the Frisbee rotates and it moves. And this rotation creates a curved path, okay? And this rotation also creates kinetic energy. Now let's look at the different types of potential energies that exist. Potential energies are energies due to positional placement in space, three types exist. Rough mass is the energy due to a stationary mass. |
Internal Energy of Matter .txt | Now let's look at the different types of potential energies that exist. Potential energies are energies due to positional placement in space, three types exist. Rough mass is the energy due to a stationary mass. Now, any mass has energy, and Einstein showed this with the equation E equals MC squared. The larger the mass, the larger the energy. Electrostatic energy is the energy due to the attraction and repulsion of the protons in the nuclei or the nucleus and the electrons in the electron cloud, okay? |
Internal Energy of Matter .txt | Now, any mass has energy, and Einstein showed this with the equation E equals MC squared. The larger the mass, the larger the energy. Electrostatic energy is the energy due to the attraction and repulsion of the protons in the nuclei or the nucleus and the electrons in the electron cloud, okay? This creates an electrostatic potential energy. Intermolecular energy is the energy due to neighboring molecules. If we go back to our system that's composed of two diatomic oxygen molecules, we see that the protons found on this nucleus will attract the electrons of the neighboring atom. |
Internal Energy of Matter .txt | This creates an electrostatic potential energy. Intermolecular energy is the energy due to neighboring molecules. If we go back to our system that's composed of two diatomic oxygen molecules, we see that the protons found on this nucleus will attract the electrons of the neighboring atom. And the same thing for this one. The proton here will attract electrons here, and they will create potential energy, okay? Now, to find an internal energy of the system, I would literally have to look at every single one of these for this molecule. |
Internal Energy of Matter .txt | And the same thing for this one. The proton here will attract electrons here, and they will create potential energy, okay? Now, to find an internal energy of the system, I would literally have to look at every single one of these for this molecule. Add that up. I would have to look at the same situation here, take all these, add them up for this one and then I would sum them together. And that would be my total or my internal energy. |
Internal Energy of Matter .txt | Add that up. I would have to look at the same situation here, take all these, add them up for this one and then I would sum them together. And that would be my total or my internal energy. Now, if I had billions of molecules, I would have to do it for every single molecule. Now, one last thing I want to mention is that internal energy is a state function. And what that means is simply that eternal energy does not depend on the process or the pathway taken to get to this system. |
Internal Energy of Matter .txt | Now, if I had billions of molecules, I would have to do it for every single molecule. Now, one last thing I want to mention is that internal energy is a state function. And what that means is simply that eternal energy does not depend on the process or the pathway taken to get to this system. What it does depend on is the current system at hand and it's also an external property. And that simply means that with increase in size of the system, internal energy of the system will also increase. And that's simply because if you increase the number of molecules in a system, there are more kinetic energies and potential energies to sum up and so that internal energy will increase. |
Autoionization Example .txt | Our second solution is a seven molar sodium hydroxide solution given also at 25 degrees Celsius. We want to find two things. First, you want to find the concentration of hydroxide. Now, seven molar nitric acid solution. And second, we want to find the concentration of hydronium in our seven molar sodium hydroxide solution. So, in the first step, we're going to do Part A. |
Autoionization Example .txt | Now, seven molar nitric acid solution. And second, we want to find the concentration of hydronium in our seven molar sodium hydroxide solution. So, in the first step, we're going to do Part A. So, first we must write the odor ionization reaction for water. So two moles of water react to produce 1 mol of conjugate acid and 1 mol of conjugate base. Now, let's write the equilibrium constants equation or expression for our odorionization reaction. |
Autoionization Example .txt | So, first we must write the odor ionization reaction for water. So two moles of water react to produce 1 mol of conjugate acid and 1 mol of conjugate base. Now, let's write the equilibrium constants equation or expression for our odorionization reaction. So, Kw is equal to concentration of hydronium times the concentration of hydroxide. So we know our Kw. That's a constant at a 25 degree Celsius, it's ten to negative 14. |
Autoionization Example .txt | So, Kw is equal to concentration of hydronium times the concentration of hydroxide. So we know our Kw. That's a constant at a 25 degree Celsius, it's ten to negative 14. Now, we also know this guy, that's seven molar because we're dealing with an acid. This is seven molar of acid. And this acid associates into H plus and some other ion. |
Autoionization Example .txt | Now, we also know this guy, that's seven molar because we're dealing with an acid. This is seven molar of acid. And this acid associates into H plus and some other ion. And this H plus increases the concentration of both this guy and this guy. And in fact, H and H 30 plus are one and the same. They're meant to represent the same thing. |
Autoionization Example .txt | And this H plus increases the concentration of both this guy and this guy. And in fact, H and H 30 plus are one and the same. They're meant to represent the same thing. So our concentration of hydronium in our solution is seven molar. So we know Kw and we know this guy. Now, we could plug it in and find our result. |
Autoionization Example .txt | So our concentration of hydronium in our solution is seven molar. So we know Kw and we know this guy. Now, we could plug it in and find our result. Now, by the way, if you're confused at this part, or if you're confused about the autoimization of water, check out the link below. So we basically take our numbers, we plug them in, and we find that 10th of the negative 14 divided by seven gives you 1.43 times ten to negative 15 molar of this guy of seven molar nitric acid solution. So this means that our concentration of our base, of our hydroxide is very, very small. |
Autoionization Example .txt | Now, by the way, if you're confused at this part, or if you're confused about the autoimization of water, check out the link below. So we basically take our numbers, we plug them in, and we find that 10th of the negative 14 divided by seven gives you 1.43 times ten to negative 15 molar of this guy of seven molar nitric acid solution. So this means that our concentration of our base, of our hydroxide is very, very small. And this means this must be a very strong acid or a very acidic solution. So let's do part two, part B in this section. So, our sodium hydroxide dissociates into sodium and hydroxide. |
Autoionization Example .txt | And this means this must be a very strong acid or a very acidic solution. So let's do part two, part B in this section. So, our sodium hydroxide dissociates into sodium and hydroxide. So this must be our base. So our seven molar concentration now refers to the concentration of hydroxide. So we simply repeat the step kw 10th to negative 14 equal it unknown times seven. |
Autoionization Example .txt | So this must be our base. So our seven molar concentration now refers to the concentration of hydroxide. So we simply repeat the step kw 10th to negative 14 equal it unknown times seven. We bring the seven over and we get divided. And we get 4.1.43 times ten to negative 15 molar of this guy of seven molar sodium hydroxide. So these two numbers have the same magnitude, but they mean two different things. |
Autoionization Example .txt | We bring the seven over and we get divided. And we get 4.1.43 times ten to negative 15 molar of this guy of seven molar sodium hydroxide. So these two numbers have the same magnitude, but they mean two different things. In this case, this means the concentration of hydroxide. That means it's a very small concentration of base. So this is an acidic solution. |
Buffer Systems .txt | Now to begin, let's suppose we have a system of one liter of pure water that has a PH of seven. Let's examine what happens to our PH when we add a small amount of acid or base to our system. Well, let's begin with the acid. Suppose we add zero one mo of HCL to our one liter system. Let's see the new PH. Well, the PH is equal to negative log zero one, and that gives us a PH of two. |
Buffer Systems .txt | Suppose we add zero one mo of HCL to our one liter system. Let's see the new PH. Well, the PH is equal to negative log zero one, and that gives us a PH of two. That means if we add this little hydrochloric acid, our PH drops by five increments. That's equivalent to a 100,000 fold increase in the hydronium concentration of our mixture. So now let's add the same amount of sodium hydroxide, a base to our system. |
Buffer Systems .txt | That means if we add this little hydrochloric acid, our PH drops by five increments. That's equivalent to a 100,000 fold increase in the hydronium concentration of our mixture. So now let's add the same amount of sodium hydroxide, a base to our system. What will be the new PH? Well, first we calculate the Poh. And the Poh is equal to negative log of 0.1,
gives it two. |
Buffer Systems .txt | What will be the new PH? Well, first we calculate the Poh. And the Poh is equal to negative log of 0.1,
gives it two. Now we subtract two from 14 and we get a PH of twelve. That means our PH increases by five increments. That's equivalent to a 100,000 fold increase in the hydroxide concentration. |
Buffer Systems .txt | Now we subtract two from 14 and we get a PH of twelve. That means our PH increases by five increments. That's equivalent to a 100,000 fold increase in the hydroxide concentration. That's a very big increase in PH. So the takeaway from this is that adding a small amount of acid or base to pure water will drastically change the PH of water. Now, if you're confused about how we got this part or this part, check out the link below. |
Buffer Systems .txt | That's a very big increase in PH. So the takeaway from this is that adding a small amount of acid or base to pure water will drastically change the PH of water. Now, if you're confused about how we got this part or this part, check out the link below. Now Aqueous solutions, unlike pure water, solutions resist changes in PH when we add acid or base. And that's because aqueous solutions have buffer systems. And a buffer is simply a chemical system which resists a PH change. |
Buffer Systems .txt | Now Aqueous solutions, unlike pure water, solutions resist changes in PH when we add acid or base. And that's because aqueous solutions have buffer systems. And a buffer is simply a chemical system which resists a PH change. So for example, suppose we had a system of 0.5 molar of acetic acid mixed with 0.5
molar of sodium acetate in one liter of water, and this PH and this system's PH was 4.74. So now what happens to our PH if we add 0.1 molar of hydrochloric acid, as we did in part A? Well, now our PH will only decrease from 4.74
to 4.72. |
Buffer Systems .txt | So for example, suppose we had a system of 0.5 molar of acetic acid mixed with 0.5
molar of sodium acetate in one liter of water, and this PH and this system's PH was 4.74. So now what happens to our PH if we add 0.1 molar of hydrochloric acid, as we did in part A? Well, now our PH will only decrease from 4.74
to 4.72. That's a change of 0.2. That's a very small change. Well, that's because this system has a buffer system. |
Buffer Systems .txt | That's a change of 0.2. That's a very small change. Well, that's because this system has a buffer system. And buffer systems are really important. For example, our blood is a buffer system. And if our PH of our blood decreases even slightly, we will suffocate and die. |
Buffer Systems .txt | And buffer systems are really important. For example, our blood is a buffer system. And if our PH of our blood decreases even slightly, we will suffocate and die. So these guys are very important. Now let's see why this happens. Now, before we look at how they work, let's look at why they work. |
Buffer Systems .txt | So these guys are very important. Now let's see why this happens. Now, before we look at how they work, let's look at why they work. What are the few requirements of buffer systems? Well, first, we have to have a weak acid and a weak base. And second, the weak acid cannot react with our weak base, because if they did, our buffer system would be neutralized and we wouldn't have a buffer to work with. |
Buffer Systems .txt | What are the few requirements of buffer systems? Well, first, we have to have a weak acid and a weak base. And second, the weak acid cannot react with our weak base, because if they did, our buffer system would be neutralized and we wouldn't have a buffer to work with. Now, what's one thing that satisfies these two requirements? Well, that's a conjugate acid base pair. Whenever a conjugate acid reacts with a conjugate base, it produces another conjugate acid and base pair for example, acetate ion and acetic acid react to produce acetate ion and acetic acid. |
Buffer Systems .txt | Now, what's one thing that satisfies these two requirements? Well, that's a conjugate acid base pair. Whenever a conjugate acid reacts with a conjugate base, it produces another conjugate acid and base pair for example, acetate ion and acetic acid react to produce acetate ion and acetic acid. So a conjugate base pair reacts to produce another conjugate base pair. So nothing is neutralized. And there are buffer remains unchanged. |
Buffer Systems .txt | So a conjugate base pair reacts to produce another conjugate base pair. So nothing is neutralized. And there are buffer remains unchanged. So normally, buffers contain equal amounts of conjugate acid as conjugate base. For example, in this buffer system, we have the same amount of acetic acid as the acetate ion. Now, some exceptions do exist. |
Buffer Systems .txt | So normally, buffers contain equal amounts of conjugate acid as conjugate base. For example, in this buffer system, we have the same amount of acetic acid as the acetate ion. Now, some exceptions do exist. For example, our blood, our blood has much more conjugate base than conjugate acid. But that's because our body produces many more acidic byproducts than basic byproducts. And so we need more base to neutralize our acid. |
Buffer Systems .txt | For example, our blood, our blood has much more conjugate base than conjugate acid. But that's because our body produces many more acidic byproducts than basic byproducts. And so we need more base to neutralize our acid. Now, let's see how these buffers work. So, for example, suppose we have the buffer system above, composed of acetic acid methodate ion. Now, suppose we add a strong base such as sodium hydroxide to our system. |
Buffer Systems .txt | Now, let's see how these buffers work. So, for example, suppose we have the buffer system above, composed of acetic acid methodate ion. Now, suppose we add a strong base such as sodium hydroxide to our system. What will happen? Well, this base reacts with our conjugate acid to produce back the conjugate base and water. So, before this base can affect our system, it's neutralized into a water molecule. |
Buffer Systems .txt | What will happen? Well, this base reacts with our conjugate acid to produce back the conjugate base and water. So, before this base can affect our system, it's neutralized into a water molecule. So our PH only changes slightly. Likewise, let's see what happens when we add acid to our buffer system. Well, hydrochloric acid first reacts with water, producing hydronium ion and the CL ion. |
Atomic Orbitals .txt | So organic chemistry is essentially the study of covalent bonds. And covalent bonds are formed by the overlap of atomic orbitals. And that means in order to understand what covalent bonds are, we must first understand what atomic orbitals are. So let's begin. So here we have so here we have Boris model. Now, Boris'model is essentially a depiction of the nucleus, the protons found in the nucleus and the electrons found orbiting our nucleus. |
Atomic Orbitals .txt | So let's begin. So here we have so here we have Boris model. Now, Boris'model is essentially a depiction of the nucleus, the protons found in the nucleus and the electrons found orbiting our nucleus. Now, according to the Boris model, and for this particular atom, our electrons are orbiting in a perfect circle. So for this atom, we have two electrons found in this circle and two electrons found in the outer circular orbit. Now, as you may or may not know, Bored model is actually an inaccurate depiction of our atomic nucleus and electrons. |
Atomic Orbitals .txt | Now, according to the Boris model, and for this particular atom, our electrons are orbiting in a perfect circle. So for this atom, we have two electrons found in this circle and two electrons found in the outer circular orbit. Now, as you may or may not know, Bored model is actually an inaccurate depiction of our atomic nucleus and electrons. And that's because electrons do not actually occupy these perfect or circular and spherical orbits. Now, Schrodinger described a pathway that our electrons follow using wave equations. So in other words, our electrons follow certain orbits, certain pathways that are not circular. |
Atomic Orbitals .txt | And that's because electrons do not actually occupy these perfect or circular and spherical orbits. Now, Schrodinger described a pathway that our electrons follow using wave equations. So in other words, our electrons follow certain orbits, certain pathways that are not circular. And what this person did is he described the pathways that they take using wave equations. Now, wave equations are simply mathematical representations of the pathways that our electrons do take. And just like any simple equation, we can also solve wave equations for solutions. |
Atomic Orbitals .txt | And what this person did is he described the pathways that they take using wave equations. Now, wave equations are simply mathematical representations of the pathways that our electrons do take. And just like any simple equation, we can also solve wave equations for solutions. And the solutions to these wave equations are called wave functions. Now, orbitals are the same thing as wave functions. So orbitals are wave functions. |
Atomic Orbitals .txt | And the solutions to these wave equations are called wave functions. Now, orbitals are the same thing as wave functions. So orbitals are wave functions. So orbitals are solutions to these wave equations. And since wave equations are simply mathematical representations of the pathway that electrons take, if we solve these wave equations, we can find the probability of an electron being at a certain region in a certain volume. And these probabilities are given by orbitals. |
Atomic Orbitals .txt | So orbitals are solutions to these wave equations. And since wave equations are simply mathematical representations of the pathway that electrons take, if we solve these wave equations, we can find the probability of an electron being at a certain region in a certain volume. And these probabilities are given by orbitals. So orbitals represent certain shapes or volumes within which our electrons are most likely in. The reason I say most likely is because orbitals are probabilities. Now, before we talk more about orbitals, let's recall what quantum numbers are. |
Atomic Orbitals .txt | So orbitals represent certain shapes or volumes within which our electrons are most likely in. The reason I say most likely is because orbitals are probabilities. Now, before we talk more about orbitals, let's recall what quantum numbers are. Quantum numbers are simply the idea of our electrons. So if we have a unique electron in a given atom, that electron has four unique quantum numbers that are unique to that electron. So we have the principal quantum number, we have the Zimmerfo quantum number, and we have two more quantum numbers. |
Atomic Orbitals .txt | Quantum numbers are simply the idea of our electrons. So if we have a unique electron in a given atom, that electron has four unique quantum numbers that are unique to that electron. So we have the principal quantum number, we have the Zimmerfo quantum number, and we have two more quantum numbers. Now, the principal quantum number gives the energy level of that electron. The second quantum number, known as the Zimmerfa quantum number gives or designates the shape of the orbital, and it's represented by the letter L, and it could be 00:12 and so on, zero being the S shape, one being the P shape, two being the D shape. The third quantum number specifies exactly which orbital that our electron is in. |
Atomic Orbitals .txt | Now, the principal quantum number gives the energy level of that electron. The second quantum number, known as the Zimmerfa quantum number gives or designates the shape of the orbital, and it's represented by the letter L, and it could be 00:12 and so on, zero being the S shape, one being the P shape, two being the D shape. The third quantum number specifies exactly which orbital that our electron is in. And the fourth quantum number gives the spin electron spin of our electron. So we could have either plus one half spin or minus one half spin. So in this lecture, we're only going to deal with the S or the P orbital. |
Atomic Orbitals .txt | And the fourth quantum number gives the spin electron spin of our electron. So we could have either plus one half spin or minus one half spin. So in this lecture, we're only going to deal with the S or the P orbital. So let's begin with the s orbital. So the s orbital, which is one of the solutions to the wave equations, is given by the spherical shape. So this sphere is the s orbital. |
Atomic Orbitals .txt | So let's begin with the s orbital. So the s orbital, which is one of the solutions to the wave equations, is given by the spherical shape. So this sphere is the s orbital. And what it basically states is that our electron is most likely in this sphere here. Now, of course, as we're talking about probabilities, there is still a probability that our electron will be found outside this spherical shape. But it's very unlikely and that's why we say it's most likely in this orbital. |
Atomic Orbitals .txt | And what it basically states is that our electron is most likely in this sphere here. Now, of course, as we're talking about probabilities, there is still a probability that our electron will be found outside this spherical shape. But it's very unlikely and that's why we say it's most likely in this orbital. So the p orbital, unlike the s orbital, have a dumbbell like shape or sideways eight. Now we have the PX orbital, we have the PY orbital and the PZ orbital. In other words, if we label this as the x axis, this as the y axis and this as the Z axis. |
Atomic Orbitals .txt | So the p orbital, unlike the s orbital, have a dumbbell like shape or sideways eight. Now we have the PX orbital, we have the PY orbital and the PZ orbital. In other words, if we label this as the x axis, this as the y axis and this as the Z axis. So Z axis is coming out of the board or going into the board. Then we have the following three orbitals. Now, if we take these guys and put them together, we get the overall p orbital and it's given by the following picture, which kind of looks like a flower, a three dimensional flower. |
Atomic Orbitals .txt | So Z axis is coming out of the board or going into the board. Then we have the following three orbitals. Now, if we take these guys and put them together, we get the overall p orbital and it's given by the following picture, which kind of looks like a flower, a three dimensional flower. Now we have the X orbital. So this guy here, we have the y orbital. So this guy here and we have this z orbital, the PV orbital which is coming out of the board. |
Atomic Orbitals .txt | Now we have the X orbital. So this guy here, we have the y orbital. So this guy here and we have this z orbital, the PV orbital which is coming out of the board. Now, just like on the XYZ axis, we have the positive side. So Y going this way is positive, x going this way is positive and D going out of the board is positive. We also have the positive sides or positive probabilities of the orbitals. |
Atomic Orbitals .txt | Now, just like on the XYZ axis, we have the positive side. So Y going this way is positive, x going this way is positive and D going out of the board is positive. We also have the positive sides or positive probabilities of the orbitals. So this green part is the positive and the blue part is the negative. Now, because we're dealing with waves and waves have nodes and anti nodes. These guys will also have nodes and anti nodes. |
Atomic Orbitals .txt | So this green part is the positive and the blue part is the negative. Now, because we're dealing with waves and waves have nodes and anti nodes. These guys will also have nodes and anti nodes. Now the nodes are these guys here. So if you could think of the eight and the eight intersects at this point. This point is the node. |
Atomic Orbitals .txt | Now the nodes are these guys here. So if you could think of the eight and the eight intersects at this point. This point is the node. And what it basically states is that our electron has a zero probability of being in this place. So the node means zero probability of finding electron at this place. That means we're never going to find an electron here, here or here, or in the cumulative picture. |
Atomic Orbitals .txt | And what it basically states is that our electron has a zero probability of being in this place. So the node means zero probability of finding electron at this place. That means we're never going to find an electron here, here or here, or in the cumulative picture. We're never going to find the electron at the origin at the point on this XYZ axis. So why are these guys important? How can we use these guys to represent pictures of our atoms? |
Atomic Orbitals .txt | We're never going to find the electron at the origin at the point on this XYZ axis. So why are these guys important? How can we use these guys to represent pictures of our atoms? Okay, so let's take an example. Let's take the carbon atom. So carbon, a neutral carbon, has six protons. |
Atomic Orbitals .txt | Okay, so let's take an example. Let's take the carbon atom. So carbon, a neutral carbon, has six protons. Hence this subscript six and six electrons. So that means if we were to draw our electron configuration, we would get this depiction. So two electrons go into this one s, two electrons go into this two s, and two electrons go into this picture here. |
Atomic Orbitals .txt | Hence this subscript six and six electrons. So that means if we were to draw our electron configuration, we would get this depiction. So two electrons go into this one s, two electrons go into this two s, and two electrons go into this picture here. But remember, we have to follow the poly exclusion principle which basically states that a maximum of two electrons can be placed into any orbital. So two electrons can be placed into the s.
Two electrons each can be placed into the PX, PY and PZ. So cumulatively, we're going to have a total, a maximum of six electrons that can be placed into this flower shaped p orbital, because this actually includes three separate orbitals. |
Atomic Orbitals .txt | But remember, we have to follow the poly exclusion principle which basically states that a maximum of two electrons can be placed into any orbital. So two electrons can be placed into the s.
Two electrons each can be placed into the PX, PY and PZ. So cumulatively, we're going to have a total, a maximum of six electrons that can be placed into this flower shaped p orbital, because this actually includes three separate orbitals. So two can be placed from here into here and into here. Now, also recall Honduras. Hans Rule basically states that before we begin completely filling these orbitals, we first have to place one electron here, one electron here, and one electron here. |
Atomic Orbitals .txt | So two can be placed from here into here and into here. Now, also recall Honduras. Hans Rule basically states that before we begin completely filling these orbitals, we first have to place one electron here, one electron here, and one electron here. So we have to go in order. And that's exactly what we do here. One electron is placed into the PX. |
Atomic Orbitals .txt | So we have to go in order. And that's exactly what we do here. One electron is placed into the PX. And one electron is placed into the PY. And that's exactly what we do here. So let's look at what happened. |
Atomic Orbitals .txt | And one electron is placed into the PY. And that's exactly what we do here. So let's look at what happened. So the electrons are the brown dots. I used brown because we already used blue, and I don't want to confuse you guys further. So the blue or the brown are our electrons. |
Atomic Orbitals .txt | So the electrons are the brown dots. I used brown because we already used blue, and I don't want to confuse you guys further. So the blue or the brown are our electrons. So the one that's orbital I did not depict. And that's because the one that's orbital is simply a smaller black sphere found within this two s sphere. This black sphere. |
Atomic Orbitals .txt | So the one that's orbital I did not depict. And that's because the one that's orbital is simply a smaller black sphere found within this two s sphere. This black sphere. Here is the two s sphere. So let's imagine that we took our two electrons and placed it into our one s. And now we're taking out two electrons and place it into the two s. The two s is this black sphere here. And I took two electrons and placed it into the black sphere, as shown here. |
Atomic Orbitals .txt | Here is the two s sphere. So let's imagine that we took our two electrons and placed it into our one s. And now we're taking out two electrons and place it into the two s. The two s is this black sphere here. And I took two electrons and placed it into the black sphere, as shown here. Now, I have one electron that I place into the X. So the green region and one electron that I placed into the Y region. So the Y orbital or the green part of the Y orbital? |
Atomic Orbitals .txt | Now, I have one electron that I place into the X. So the green region and one electron that I placed into the Y region. So the Y orbital or the green part of the Y orbital? And that's the picture. Or the picture using atomic orbitals of our carbon. Now. |
Atomic Orbitals .txt | And that's the picture. Or the picture using atomic orbitals of our carbon. Now. We'll see in later lectures how when these guys interact with other orbitals, with other atoms, they form something called covalent bonds. Now let's look at neon. Now. |
Atomic Orbitals .txt | We'll see in later lectures how when these guys interact with other orbitals, with other atoms, they form something called covalent bonds. Now let's look at neon. Now. Neon has ten protons and ten electrons. In fact, it has a perfect electron configuration. It's a noble gas. |
Atomic Orbitals .txt | Neon has ten protons and ten electrons. In fact, it has a perfect electron configuration. It's a noble gas. So all the electrons, all the atomic orbitals should be filled. So let's look at our electron configuration. So we have one s, two, two s, two, two PX, two, two p y two and two PZ, two. |
Atomic Orbitals .txt | So all the electrons, all the atomic orbitals should be filled. So let's look at our electron configuration. So we have one s, two, two s, two, two PX, two, two p y two and two PZ, two. So once again, two electrons go into the one s which isn't shown. Two electrons go into the two s, which is shown. And here we have two electrons. |
Atomic Orbitals .txt | So once again, two electrons go into the one s which isn't shown. Two electrons go into the two s, which is shown. And here we have two electrons. Two electrons go into our x orbital, two electrons go into the two p y orbital and two electrons go into the two PZ orbital. So all the Orbitals all the Green Orbitals are filled. And so this is our atomic orbital representation of our neon, in which it has a perfect election configuration. |
Introduction to Resonance Forms .txt | A lewis structure is simply an electronic configuration of our atoms, our molecules and compounds. So let's begin by using formaldehyde. So we're going to have this compound that's compared composed of one carbon, one oxygen and two h atoms. Now we're going to draw the lewis down structure for our formaldehyde. So our first step is to count the number of balanced electrons. Balanced electrons, once again, of those electrons that come from the outermost shells of our atoms. |
Introduction to Resonance Forms .txt | Now we're going to draw the lewis down structure for our formaldehyde. So our first step is to count the number of balanced electrons. Balanced electrons, once again, of those electrons that come from the outermost shells of our atoms. So oxygen has six valence electrons, carbon has four valence electrons, and h has one each. We have two h, and so two valence electrons come from our two HS. So we have a total of twelve balanced electrons. |
Introduction to Resonance Forms .txt | So oxygen has six valence electrons, carbon has four valence electrons, and h has one each. We have two h, and so two valence electrons come from our two HS. So we have a total of twelve balanced electrons. So let's begin drawing our loose dot structure. So we have carbon, two h's and 10. So let's begin by first drawing our sigma, or Covalent bonds. |
Introduction to Resonance Forms .txt | So let's begin drawing our loose dot structure. So we have carbon, two h's and 10. So let's begin by first drawing our sigma, or Covalent bonds. So we have two bonds between the chas, and we have one bond between the oxygen. So here's our Covalent sigma bond, covalent sigma bond, and Covalent sigma bond. So so far, we have used up six balance electrons. |
Introduction to Resonance Forms .txt | So we have two bonds between the chas, and we have one bond between the oxygen. So here's our Covalent sigma bond, covalent sigma bond, and Covalent sigma bond. So so far, we have used up six balance electrons. We have six more balanced electrons that we can use. Notice that carbon and oxygen both can develop double bonds. So let's create a double bond between carbon and oxygen. |
Introduction to Resonance Forms .txt | We have six more balanced electrons that we can use. Notice that carbon and oxygen both can develop double bonds. So let's create a double bond between carbon and oxygen. So we place two electrons and we create a pi bond. So now we have four more balanced electrons we can place, and we place them around the oxygen like so. Now, because oxygen has 123456, carbon has 1234, and h has one each, this is a neutral lewis structure, lewis form. |
Introduction to Resonance Forms .txt | So we place two electrons and we create a pi bond. So now we have four more balanced electrons we can place, and we place them around the oxygen like so. Now, because oxygen has 123456, carbon has 1234, and h has one each, this is a neutral lewis structure, lewis form. Now, the following problem arises. Now, this is not the only lewis structure that exists. Others exist. |
Introduction to Resonance Forms .txt | Now, the following problem arises. Now, this is not the only lewis structure that exists. Others exist. And in fact, here's one other one. Instead of creating that pi bond, by placing those two balanced electrons into our pipeline here, we could have simply placed those two electrons on oxygen, and that would create another lewis dot structure. However, this structure has a negative charge on oxygen and a plus charge on the carbon, because we only have one, two, three bonds here, and we have 123-4567 electrons on the oxygen. |
Introduction to Resonance Forms .txt | And in fact, here's one other one. Instead of creating that pi bond, by placing those two balanced electrons into our pipeline here, we could have simply placed those two electrons on oxygen, and that would create another lewis dot structure. However, this structure has a negative charge on oxygen and a plus charge on the carbon, because we only have one, two, three bonds here, and we have 123-4567 electrons on the oxygen. So notice the following. We have two different lewis structures for formaldehyde, and in fact, this idea, this concept is called resonance. And these structures, lewis dot structures, are called resonant forms. |
Introduction to Resonance Forms .txt | So notice the following. We have two different lewis structures for formaldehyde, and in fact, this idea, this concept is called resonance. And these structures, lewis dot structures, are called resonant forms. So let's define resonant forms. Resonant forms are the different combination of the possible lewis dot structures for our compounds. Now, whenever we draw resonant forms, the following two things have to always be kept in mind. |
Introduction to Resonance Forms .txt | So let's define resonant forms. Resonant forms are the different combination of the possible lewis dot structures for our compounds. Now, whenever we draw resonant forms, the following two things have to always be kept in mind. The first one is, since lewis structures are electronic configurations, we only move electrons and we never move any atoms. Now, notice what this arrow represents. This arrow is known as arrow formulasm. |
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