Given the values of ΔH°_rxn, ΔS°_rxn, and T, determine ΔS_univ and predict whether or not each reaction is spontaneous. (Assume that all reactants and products are in their standard states.) c. ΔH°_rxn = +95 kJ; ΔS°_rxn = -157 J/K; T = 298 K

Video transcript

Hello. Everyone in this video we're trying to calculate for our delta s and we're also trying to predict the reaction or when the reaction will be spontaneous. So let's first start off by recognizing that's what we need to solve for is going to equal to the delta us of our system plus our delta us of our surroundings. All right. So stirring off by calculating for my delta us of the system that's going to equal to the delta us reaction. And looking at what were given in the problem, we can see right over here, It's going to be negative 251 draws per kelvin. Just go ahead and write that up -2 tools kelvin. All right now my delta S for surrounding, that's going to equal to negative delta edge reaction provided by T in that case then will have instead of So we have our delta agent reaction given to us in the problem right over here In the beginning, you are the negative of that? That's going to be -56 Killer Jewels. Let's go ahead and convert the killer jewels into jewels, 10 to the third on top And one killer jewel on the bottom. That's going to go ahead and convert our killer jewels into jewels. Then of course we are divided by our teeth. So divide one over The temperature, given the problem to us is 206 Kelvin's. So one over 206 Kelvin's putting all this into my cap there. I'll get the value of -2 71.84 units being jewels per Kelvin. Alright, so now let's go ahead and solve for delta. Yes, so that's what we're looking for here. That's going to be equal to negative jules, kelvin minus 71.84 Jewels per Kelvin. So what we did here was just plug in the numerical values for this purple equation. Alright, so this is kelvin. Okay, Now putting this into my calculator, I'll get the value of -523 jules Kobe. That's going to be one of our answers. That the questions asking for next. Let's go ahead and scroll down just a little bit here. Just so we can have a little bit more space. All right now we need to see when it would be spontaneous or if it is spontaneous at all. So we have our delta jeep. That's going to help determine if this is going to be spontaneous or not spontaneous. So delta jeep, let's go to equal to our delta H minus T. Multiplied by delta S. All right, so we have all these values already. We see, Go ahead and plug it in. So our.h is positive 56 killer jewels. We're going to subtract The T, which is 206 Calvin's multiplied by our delta s. That's going to be negative 2 jewels per kelvin and then now I'm going to want to actually convert our jewels into jewels. So we could go ahead and subtract with our delta H. Right when you hear properly. And so we just have one killer jewel And the numerator and 10 to the third jewels as my denominator. And this will cancel out the the jewels. So put all this into my calculator. The numerical values may be 108 and my units is going to be killing jewels. So as you can see here, then we have a positive delta G. Like that. So we have a positive value for our delta G. And therefore it means that the reaction is going to be non spontaneous. Alright, so this is going to be the last and final answer for our problem. So again we have this here and this. All right, thank you all so much for watching.