A certain constant-pressure reaction is barely nonspontaneous at ...

Question

A certain constant-pressure reaction is barely nonspontaneous at 45 °C. The entropy change for the reaction is 72 J>K. Estimate ΔH.

Accepted Answer

well everyone in this video, we're trying to determine the value of delta H. If the change of entropy is our delta S value for the reaction is 96 joules per kelvin. So of course we're gonna go ahead and relate these two with the gibbs free energy equation. But first things first, let's go ahead and convert the given temperature into our kelvin units. So it's given to us in Celsius 65°C, we can just go ahead and add 273.15 to give us 338.15 Kelvin's. So again the keyboard here is slightly non spontaneous. If we have that then let's go ahead and just draw this arrow here that the delta G is going to be greater than zero. So we have a positive value. So now bringing out the gibbs free energy equation. The delta G is equal to the change of entropy minus. The temperature, multiplied with the change of entropy. And of course as we said, that's going to be greater than zero. So our delta H. Is being subtracted by a temperature that we saw for two B 338.15 Calvin's then multiplied with our adult to us. And that's Given to us again, 96 jewels per Kelvin's, that's going to be greater than zero. So putting that into my calculator, it's going to be that delta H is subtracted from 3 to 462.4 jewels Again greater than zero. So it was kind of isolating our delta H. And we see here that we get the positive value of 3 to 462.4 jules. Let's go ahead and actually convert this into killer jewels. We can do a direct conversion for everyone. Killer jewels, we have 1000 jewels is here that the units of joules will cancel. So finalizing my delta age value to be greater than 32 killer whales. So if our delta S. Is positive and non spontaneous, the reaction must be an author Mick. And then we have this slightly non spontaneous reaction. The magnitude isn't greater than or can't be greater than R- 32 kg jewels. So to put this in writing, then the final answer is that the magnitude of delta H is not much greater then 32 killer jewels. And this right here is going to be my final answer for this problem. Thank you all so much for watching.

A certain constant-pressure reaction is barely nonspontaneous at 45 °C. The entropy change for the reaction is 72 J>K. Estimate ΔH.

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