Hi thanks for the great video.May I ask a question on the first part of the lecture? You said the number of moles are constant.But in a reaction like A+B=C won't the number of moles change. And if that were the case, now that P and T is constant, and n can change as shown the the equation, won't V also be able to change? But even if that were the case,delta H would still be equal to the heat exchanged Q since the pressure of the system is held constant?But im not sure about why n is constant.
well at 1.55 , DELTA H FORWARD = - DELTA H REVERSE , IT IS STATED UNDER LAVOISIER AND LAPLACE LAW NOT THE HESS LAW . OTHERWISE EVERYTHING IS GUD AND FINE , INFORMATIVE VIDEO BUT IT WAS UNDER LAVOISIER AND LAPLACE LAW NOT HESS LAW .
Thanks for this video, very helpful! Still, something remains unclear to me, maybe you would be so kind to answer it? The thermodynamic potential for G = U - TS + PV, with U the inner energy. With dU = T dS - PdV (no particle exchange assumed), this leads to dG = -SdT + VdP. You said that the derived equation, dG = dH - TdS, only holds for constant pressure and constant temperature (dP=dT=0). But then for the above eq. we have: dG = -SdT + VdP = 0 = dS_universe What is going on here?
Thank you for a very helpful video. At least to me , it makes clear how the Gibbs Free Energy relation is "derived" from a consideration of the second law in the form -- change in entropy of the universe is always non-negative. I do, however, have one problem with the derivation. In step 2 you use the ideal gas law to allow setting delta_V to zero. in a liquid (not gaseous) case isn't it true that the volume could also change in a chemical reaction?
Also, I was also thinking if we were to state that yes the number of moles, remains constant, what if some of the n aren't gas molecules. that would also mean that the n in the formula PV=nRT isn't constant too. So these 2 are the main questions i have on why n must be a constant for this to happen.
It seems that there is a mistake here.. In gibbs free energy, only T and P is assumed to be constant, not V. I think the presenter confuses it with helmholtz free energy. In helmholtz free energy, T and V is taken constant, not P.
who is an american??? or should i say...the american. 1st Obama now trump both of whom are americans. perhaps the only thing they have in common apart from the being a president
if you're looking for the uni level derivation (G naught and such), this isn't it, turn back now
if you have a link, would you mind sharing? Thank you.
Τhank you
Hey! The change in enthalpy is zero for all elements in their standard states (1 bar pressure).
I am happy that the video helped. What kind of help did you have in mind?
how can we find the proof of delta(G)=delta(G)0-RTlnQ equation?
Glad it helped! You're welcome :)
Thank you! Happy to know it helped
i did not get the part where you said that -T(delta)S is gibbs energy....7th step....HOW ?
+Kwaku Brobbey but ist it supposed to be deltaG= deltaH- T(delta)S
thankyou !
Hi thanks for the great video.May I ask a question on the first part of the lecture?
You said the number of moles are constant.But in a reaction like A+B=C won't the number of moles change. And if that were the case, now that P and T is constant, and n can change as shown the the equation, won't V also be able to change?
But even if that were the case,delta H would still be equal to the heat exchanged Q since the pressure of the system is held constant?But im not sure about why n is constant.
I like this derivation as you show the importance of entropy in the wider universe in determining which reactions are allowed and which are not.
Thanks ❤❤
well at 1.55 , DELTA H FORWARD = - DELTA H REVERSE , IT IS STATED UNDER LAVOISIER AND LAPLACE LAW NOT THE HESS LAW . OTHERWISE EVERYTHING IS GUD AND FINE , INFORMATIVE VIDEO BUT IT WAS UNDER LAVOISIER AND LAPLACE LAW NOT HESS LAW .
thankyou sir
Thanks for this video, very helpful!
Still, something remains unclear to me, maybe you would be so kind to answer it?
The thermodynamic potential for G = U - TS + PV,
with U the inner energy.
With dU = T dS - PdV (no particle exchange assumed),
this leads to dG = -SdT + VdP.
You said that the derived equation, dG = dH - TdS, only holds for constant pressure and constant temperature (dP=dT=0). But then for the above eq. we have:
dG = -SdT + VdP = 0 = dS_universe
What is going on here?
ABSOLUTELY NOTHING...HIS EXPLANATION IS DRACONIAN AND IRRELEVANT..
thanks very much.... i was not able to understand.. but now i am very good at this
What about open system, where mass id also exchanged ?
Thank you for a very helpful video. At least to me , it makes clear how the Gibbs Free Energy relation is "derived" from a consideration of the second law in the form -- change in entropy of the universe is always non-negative. I do, however, have one problem with the derivation. In step 2 you use the ideal gas law to allow setting delta_V to zero. in a liquid (not gaseous) case isn't it true that the volume could also change in a chemical reaction?
Also, I was also thinking if we were to state that yes the number of moles, remains constant, what if some of the n aren't gas molecules. that would also mean that the n in the formula PV=nRT isn't constant too.
So these 2 are the main questions i have on why n must be a constant for this to happen.
Great video
great video thanks for your help!
Thank you
Thanks sir❤
hai! can you explained about the equilibrium constant in Gibbs free energy..how the formula was formed
Its amazing really very helpfull
Can you please reply me cuz I am in a pharmacy school and learning physical chem and wants a lot of help please
Thankyou bro😭
When is delta H sys zero?
I am now learning Phs. Chem 239 and A lot of cocepts I cant get it from our intructor , now we have finished 1st and 2nd law of thermo dynamics
It seems that there is a mistake here.. In gibbs free energy, only T and P is assumed to be constant, not V. I think the presenter confuses it with helmholtz free energy. In helmholtz free energy, T and V is taken constant, not P.
Hi
Cool vid
Kaunsa desh ka hai be
are you american? you dont sound like one
who is an american??? or should i say...the american. 1st Obama now trump both of whom are americans. perhaps the only thing they have in common apart from the being a president
I like this derivation as you show the importance of entropy in the wider universe in determining which reactions are allowed and which are not.