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Sp Hybridization.txt | So we input two atomic orbitals, and we get two molecular orbitals. |
Sp Hybridization.txt | So we get the one lower in energy and the one higher in energy. |
Sp Hybridization.txt | So, once again, let's recap. |
Sp Hybridization.txt | So hybridization is simply a process that occurs within an atom. |
Sp Hybridization.txt | Within an atom, the orbitals can interact in a way to produce these hybridized orbitals that contain larger sections and smaller sections. |
Sp Hybridization.txt | The largest sections are able to better interact with other orbitals found on other atoms as they produce better, more stable bonds. |
Sp Hybridization.txt | Now, we've only spoken about SP hybridized orbitals in the next lecture we're going to look at the SP two and SP three hybridized orbitals. |
Sp Hybridization.txt | You. |
Mass percent example.txt | Mass percentage is simply another way of finding the concentration of the solution. |
Mass percent example.txt | Mass percentage is equal to mass of some compound x divided by the total mass of the solution times 100. |
Mass percent example.txt | The 100 gives you the percentage. |
Mass percent example.txt | This is a fraction, so you divide mass by mass, so the units cancel out. |
Mass percent example.txt | So mass percent is unitless. |
Mass percent example.txt | Now let's do a problem with mass percentage. |
Mass percent example.txt | The question tells us that we have 49 grams of gold, 25 grams of carbon, .5 water. |
Mass percent example.txt | We need to find the mass percent of carbon, water and gold in our solution. |
Mass percent example.txt | The first step is to find the mass percentage of gold. |
Mass percent example.txt | To find the mass percentage of gold, we simply use the formula. |
Mass percent example.txt | So 49 grams of gold divided by the total mass of the solution, 49 grams plus 25 grams plus now we can't add kilograms to grams. |
Mass percent example.txt | So the first step is to convert this to grams. |
Mass percent example.txt | We get plus 500 grams. |
Mass percent example.txt | Now we multiply the whole thing by 100 to find the percentage, and we get 8.5%. |
Mass percent example.txt | The mass perceptive of gold is 8.5. |
Mass percent example.txt | To find the mass perceptive carbon, we follow the same exact formula. |
Mass percent example.txt | 25 grams of carbon divided by the total grams of the solution multiplied by 100 gives us 4.4%. |
Mass percent example.txt | So the max percent of carbon is 4.4. |
Mass percent example.txt | The last step could be done in two ways. |
Mass percent example.txt | One way, you simply use the formula. |
Mass percent example.txt | You plug things in, you find the result. |
Mass percent example.txt | A quicker way would be simply to realize that if you add these guys up and subtracted from 100, we get the mass percent of the final thing final compound within our solution. |
Mass percent example.txt | Namely water. |
Mass percent example.txt | So 100 -8.5 plus 4.5 gives you 87. |
Mass percent example.txt | 1% the mass percent of water within our solution is 80 is 87.1%. |
Second Law of Thermodynamics .txt | The second law of thermodynamics comes from the idea of the heat engine. |
Second Law of Thermodynamics .txt | And what it basically says is that heat cannot be completely converted into work. |
Second Law of Thermodynamics .txt | From the side ramp here of the heat engine, we can see that that's the case. |
Second Law of Thermodynamics .txt | The energy that comes from the hot body, some of that energy goes into doing work, expanding the piston increase, increasing the volume. |
Second Law of Thermodynamics .txt | And some of that goes into the cold body, decreasing the temperature as the piston moves back into its original position, thereby keeping the temperature constant. |
Second Law of Thermodynamics .txt | Okay, we know by conservation of energy that the input energy equals the output energy. |
Second Law of Thermodynamics .txt | That means QH, which means the energy input is equal to QC, the energy transferred into the cold body plus the work done by the system or by the molecules within the system. |
Second Law of Thermodynamics .txt | And this directly correlates the first law of thermodynamics. |
Second Law of Thermodynamics .txt | And in fact, it's the same thing. |
Second Law of Thermodynamics .txt | It's basically this. |
Second Law of Thermodynamics .txt | Okay, so we basically are saying that engines, heat engines aren't completely 100% efficient in converting heat into work. |
Second Law of Thermodynamics .txt | So how efficient are they? |
Second Law of Thermodynamics .txt | Well, this formula here where E stands for efficiency or engine efficiency, can basically tell you how efficient an engine is. |
Second Law of Thermodynamics .txt | If you know the temperature of the cold body and the temperature of the hot body, you can find the efficiency. |
Second Law of Thermodynamics .txt | And this also shows you can see from algebra and basic calculus that ends, this becomes zero or tenths of zero. |
Second Law of Thermodynamics .txt | That is, as TC decreases and Th increases or the difference between these two guys increases, the efficiency also increases. |
Second Law of Thermodynamics .txt | Okay? |
Second Law of Thermodynamics .txt | You can pluck some values in and you'll see that as this becomes smaller and this becomes larger, that E becomes more efficient. |
Second Law of Thermodynamics .txt | Okay, finally, let's talk about refrigerators and air conditioners. |
Second Law of Thermodynamics .txt | So refrigerators and air conditioners are basically reverse heat engines. |
Second Law of Thermodynamics .txt | What actually happens is work is inputted so that heat can be transferred from a cold body to a hot body or energy can be transferred from a cold body to a hot body. |
Second Law of Thermodynamics .txt | This decreases the temperature of the system but increases the temperature of the outside. |
Second Law of Thermodynamics .txt | For example, in this room in the summer, if I have an air conditioner and I plug it into the outlet, the energy that goes into the air conditioner basically does work on the inside room. |
Second Law of Thermodynamics .txt | And what it does is it takes away energy from the inside room and throws the energy to the outside. |
Second Law of Thermodynamics .txt | So what happens is the inside of the room is cooled, but the outside is heated or the temperature on the outside increases because on top of the work that's inputting, there is this QC that's input as well. |
Second Law of Thermodynamics .txt | And this addition means that the outside temperature must increase. |
Homo-Lumo interactions.txt | In this lecture, I'd like to examine the homoluma interaction between compounds. |
Homo-Lumo interactions.txt | So let's look at the following example. |
Homo-Lumo interactions.txt | Let's suppose we have compound one and alkane reacting with compound two, our hydrochloric acid. |
Homo-Lumo interactions.txt | So this is a simple additional reaction. |
Homo-Lumo interactions.txt | So in this reaction, this alkin actively lowers based base. |
Homo-Lumo interactions.txt | This acts as a lewis acid. |
Homo-Lumo interactions.txt | So this donates a pair of electrons. |
Homo-Lumo interactions.txt | This accepts a pair of electrons. |
Homo-Lumo interactions.txt | So our intermediate reactants are the intermediate carbocation that has a positive charge on this carbon and has an extra h that it got from the hydrochloric acid. |
Homo-Lumo interactions.txt | Now, this chlorine, or chloride atom now has an extra pair of non bonding electrons, and so it develops a negative charge. |
Homo-Lumo interactions.txt | In the second step of this addiction reaction, we have the chloride ion donating a pair of non bombing electrons. |
Homo-Lumo interactions.txt | So this is our lewis base and our lewis acid. |
Homo-Lumo interactions.txt | And so we form the following final product. |
Homo-Lumo interactions.txt | So, let's examine this picture more closely using molecular and atomic orbitals. |
Homo-Lumo interactions.txt | So let's draw our molecular orbitals or atomic orbitals for this reaction. |
Homo-Lumo interactions.txt | So, here's our alkane. |
Homo-Lumo interactions.txt | So our sigma bond and our pi bond, creating the double bond. |
Homo-Lumo interactions.txt | What happens is this pair of electrons. |
Homo-Lumo interactions.txt | So, this bond is composed of a pair of electrons, one electron in this two p orbital and the second electron in this two p orbital. |
Homo-Lumo interactions.txt | So these two electrons attack this h atom, taking that h atom away from this chlorine atom. |
Homo-Lumo interactions.txt | And we develop the following diagram. |
Homo-Lumo interactions.txt | So, this is our intermediate cargo cation. |
Homo-Lumo interactions.txt | So, this bond has been formed, this cobalt sigma ch bond. |
Homo-Lumo interactions.txt | And now we have a positive charge on this twopie orbital because we have 1233 electrons. |
Homo-Lumo interactions.txt | And that means we have a positive charge on the two p orbital. |
Homo-Lumo interactions.txt | So, once again, this is SP two hybridized, and this is a planar molecule. |
Homo-Lumo interactions.txt | So what happens next? |
Homo-Lumo interactions.txt | Well, next we have this lewis base. |
Homo-Lumo interactions.txt | We have our chloride atom. |
Homo-Lumo interactions.txt | And this non bonding pair of electrons attacks or attaches overlaps with this two p orbital, forming our spinal product. |
Homo-Lumo interactions.txt | So, in the first step, this pi bond acted as a lewis base, donating this pair of electrons and this h atom on this compound on the hydrochloric acid active as a lewis acid, donating that h, donating that empty one s orbital. |
Homo-Lumo interactions.txt | And likewise, here, this is the lewis acid because it has an empty two p orbital. |
Homo-Lumo interactions.txt | And this is the lewis base because it has a pair of non bonding electrons. |
Homo-Lumo interactions.txt | So, what exactly is a lewis athens based reaction? |
Homo-Lumo interactions.txt | So, a lewis athens based reaction is the interaction between a filled molecular orbital, as we saw here, and an antimolecular orbital. |
Homo-Lumo interactions.txt | And this is known as a homolumo interaction. |
Homo-Lumo interactions.txt | Homo simply meaning highest occupied molecular orbital, and lumo, meaning lowest unoccupied molecular orbital. |
Homo-Lumo interactions.txt | So if we go back to the first step in this additional reaction, we see that our homo, the highest occupied molecular orbital, is the pi bond. |
Homo-Lumo interactions.txt | So this is our lowest base. |
Homo-Lumo interactions.txt | And in this case, our lowest unoccupied molecular orbital is the antibonding Sigma Bond. |
Homo-Lumo interactions.txt | Remember, the bonding Sigma Bond is completely filled. |