Internal Energy

so internal energy uses the variable of Delta E, which is the Mawr common variable, or Delta U, which is the less common variable. But you might see either one. So be mindful that both mean internal energy here. We're going to say it represents the total energy from all forms of kinetic and potential energy of a system. Now we're gonna say internal energy can be calculated as Delta E equals Q plus W. So this is our understanding when it comes to the internal energy of a system. Now that we have this basic equation, click on to the next video. Let's go a little bit deeper in terms of it.

Now, with the internal energy of a system, we have the internal energy formula. We're going to say this formula is used when we have the heat and work of a system. We know that Delta E equals Q plus w Delta E is our internal energy. It could be in either jewels or kill a jewels. Q represents our heat. It could also be in jewels or kill jewels and then w equals work. Now, with work, we have an additional formula here. The work formula is used when we have the pressure and volume of a system here, work equals negative p times Delta V. So we're gonna say here P equals pressure in atmospheres. V equals volume in leaders. And then we're gonna say leaders times atmospheres is equivalent to one a 1.3 to 5 jewels. Now, this is important because if a work is given in leaders times, atmospheres, then we use this conversion factor here to change it into jewels. And we're going to say here, connected to this idea of heat and work is another term envelop, which uses the variable of Delta H. We're going to say it represents the amount of heat released or absorbed during chemical reaction. It should sound kind of familiar to you. We're going to say here that at constant pressure, entropy and heat can be treated as the same variable. So a constant pressure. We're going to say here that entropy, which is Delta H, is equal to heat, which is cute. So keep these formulas in mind because remember, if it has a purple box around it, that means you're responsible for memorizing it for any upcoming quizzes or exams. So remember, internal energy equals Q Plus W, and work equals negative pressure. Times change in volume.

here, we're told. What is the internal energy of the system? If the reaction is done at a constant pressure of 20 atmospheres and the volume compresses to leaders to five leaders while releasing 92 point to kill jewels of heat? Alright, so internal energy is delta eat and it equals Q plus W. They tell us that we're releasing 92.2 kg of heat. Remember, if you're releasing heat, it has a negative sign. So it's negative 92 to kill a jewels. Since heat is in killing jewels, work needs to be in kill jewels. Remember, work equals negative pressure. Times change in volume. So negative 20 0 atmospheres. Times change in volume, which is final minus initial. So five liters minus 10 liters. So here, when we do that, that's going to give me a positive. Okay, 100 leaders, times, atmospheres and here we need killer jewels for work. So we're gonna have to do some converting. So we have 100 liters times. Atmospheres. Remember one leader times at one leader times atmospheres equals one on 13 to 5 jewels. And then remember one killer Jewell is equal to tend to the three jewels. So that's gonna give me 10.13 Yeah. 25 jewels here will just round to 10.13 jewels. I'll kill jewels. Now, we're gonna take that and plug it in. So here, I'm going to take this is my work and plug it into here. So now we're gonna plug this into our calculators, and when we do, that's gonna give us the internal energy of our system. So let me read. Write it down here. So we're gonna say Delta E equals Q plus W. So what equals negative? 92.2 plus 10. So when we do that, we're gonna get our answer as negative 82. Killer jewels. This tells me how much energy my system has lost. Do this process. So just remember, internal energy equals Q plus W