5.2 | MSE104 - Gibbs Energy Curves

[@ezanadaniel9149]

you have no idea how much this helped me, thank you so much professor

[@sashatupalo]

This is very helpful, informative and clear! Thanks! Worcester Polytechnic Institute student

[@nirmalbaishnab8054]

Perfectly paced, well organized, very helpful.

[@wcm8989]

This was well taught, Thanks a lot! it will really help me during my final. Student from the University of California Irvine!

[@gomaa2020]

Your are the best ever seen explaining such a problem. Appreciated

[@ounggilkwon7161]

Wow thanks you very sooo much. I'm Korean University Student. Now I studied Phase Diagram, your explanation was a great help me. Thank you ;)

[@maysamseif8337]

In a binary eutectic phase diagram with no solid solution at the eutectic temperature, do the alpha and beta curves and the liquid curve all sit on each other at the eutectic composition?

[@kevinsangoi4781]

Thank you for making it so easy and clear ! Virginia Tech student.

[@geoarth_coaching]

Great Lecture Sir!! I was looking to widen my view on G-X Curves before I could shoot my lecture and your video is very informative. Thank You for the help. Keep making great content.

[@jonathansnow1886]

Why are a1 and a2 not considered separate phases with distinct concave upward G(x) functions?

[@aykutaykac2587]

Why do you write L+a in 25:00? It should be L+b?

[@gokberkdemirok8354]

Very helpful lecture, thank you. How G vs Xb curve will look like at the temperature where the miscibility gap starts (i.e. at the peak of the miscibility gap curve), thank you.

[@flyingbeaver123]

I get the graphical representation for the sake of being concise, but how do you calculate the Gibbs free energy of the solid in the liquid region of the phase diagram?

[@whysoserious0609]

Hi, can anyone help me, is the first example with alpha ,alpha1 and 2 means they are one phase just with different composition?

[@itsamankumar403]

Thank you for sharing professor :)

[@vincemaz]

really good and understable video ! thank you verymuch from france !

[@josecarlosdelgadomalave2353]

Could you help me understand how is it possible that a phase that does not exist (solid, 7:03) has a gibbs energy curve? shouldn't there be just one liquid curve? very good lecture, thanks

[@DavidDyeIC]

Well, if the solid did form, then it would have an energy that would vary with composition. For a given composition, there might be a lower energy phase that could form, in which case that would be the preferred thing to happen. Make sense?

[@josecarlosdelgadomalave2353]

David Dye wow thank you very much for taking the time to respond, I have asked this question to several people and all of them told me that "since te liquid has a lower energy than the solid for any composition that means that the liquid phase is the one that is in equilibrium, the only one than can exist" I understand that, I just want to know how the solid curve can be drawn in the first place? I guess it doesn't matter whether the phase exist or not but how? If there isn't a solid phase at that tempersture for any composition how can exist the energy curve for such phase? is it because an ecuation? If so, what data you use if the solid is not present? Sorry if I am asking too much is just that is a like a splinter in my head not knowing the answer...I haven't been able to find it in my book or online. Thank you!

[@DavidDyeIC]

Well, its a theoretical idea, right? That is, whether or not we can measure it (actually quite hard) and whether or not we observe it doesn't mean that the liquid phase at some composition would have an energy, so we can draw that curve. There are several consequences: for instance, think of material that isn't at equilibrium yet. i.e. I take some liquid and I cool it down to below its freezing point. Then the amount of Gibbs Energy available to be released when it transforms to solid is the difference between the Gibbs energy of the liquid and solid. And for a natural transformation, it can only go in one direction - the one that lowers G. So its *useful* to be able to draw that curve.

[@josecarlosdelgadomalave2353]

David Dye thank you very much. I understand it a little better now :)

[@williamortez4592]

Fantastic video! This was very clear

[@kkuhn]

Absolutely exceptional lecture

[@viniciusdegois5986]

thank you verymuch from Brazil!!!

[@sandy700ss]

How do you know how far up or low the gibbs curve of alpha should be, and how large it should be?

[@tfs283]

What is the next lecture following this one? Very interested in the metastable explanations!

[@martinolowe6516]

do you have a video relating gibbs energy to activity diagrams?

[@chisechee874]

book

[@muhaedalali7232]

Thank you so much for your lecture, it is really clear and useful

[@hakanmustafatunc5387]

Thank you very much! But how do we know the minima's? I mean the slope of a tangent line matters?

[@vikaspremium1248]

Shouldn't it be L+beta in the diagram with eutectic region ?

[@sairamgoud7127]

Sir I could not understand how to draw the G-X curve at the eutectic temperature .Could you please explain clearly as their alpha+liq,beta +liq,Alpha+beta ,co exist in the equilibrium

[@burcmm]

In the Eutectic phase diagram, won't the Gibbs energy of the liquid at the last temperature (lowest one where there is alpha, alpha+beta and beta only) be much higher than energies of alpha and beta in the entire range of composition? Or should I see it as the following: A composition that happens to be on the liquid curve (which has lower energy compared to pure alpha or pure beta somewhere at mid composition of B according to the curve you drew), say at 50 weight percent of B, will just form alpha and beta phases according to the common tangent construction. Thank you.

[@DavidDyeIC]

At the eutectic temperature, the common tangent touches the Gibbs energy curves of all three phases. If the two solid phases are on either side of the eutectic point, there is no other way to draw it other than to find the liquid in between their energies, as drawn. So the eutectic is the 'triple point' of the system, if you like.

[@tanners1456]

At 23:35 (the bottom right graph) what dictates the relative y position (Gibbs energy) of the alpha and beta curve minimums? Could the alpha minimum in fact be at the same Gibbs level as the beta minimum or even higher? This is the only part that is not clear to me, other than this it is very well explained.

[@allahbakhsh5212]

i need a lecture on huron-vidal mixing rule please

[@alaafaad600]

why the solid has less gibbs energy in third graph but in part of liquid however we dont have solid it has more gibbs energy

[@mathsk1081]

Did not get why it is the position where the slope of S and L is the same (tangent) and not the direct minimum. Do you know a link for an "algebraic/ physical" explanation.

[@mrmendicantbias]

Drawing a common tangent between the global minima of two free energy curves requires would be impossible in almost all cases as the line would penetrate at least one of the curves. Imagine two identical curves separated by some distance x, but at the same y positions; the common tangent would touch the two global minima. Now, keeping that tangent in place, shift one of the curves upwards. You may readily imagine that the point of contact would need to shift away from the minima as the line's rotation would eventually cause it to penetrate the curves, which is a violation of the tangential condition.

[@naveedstegamat6283]

This is great thank you

[@raniakantzou4675]

this video is soooooooooooooooooo good

[@gibbs-13]

dG=dH-TdS. so, if we decrease the temperature, I thought that dG of alpha or beta gets increased. why does the dG get lower and lower?

[@markmulakazuwa1031]

great explanation thank you zimbabwe student

[@うめきち-j3h]

quite helpful! thanks from japan

[@synthboy17]

The lecture is very well presented. But I can't understand the mathematical significance of the Common Tangent construction, and its mathematical equivalence to Chemical Potential equilibrium. Kindly explain

[@PooKulseekers]

Common tangent means the slope(G VS X )is same for the equilibrium phases . dG/dx =Chemical potential.

[@HinaKhan-og5km]

thank you so much your lecture helps alot

[@lovelyplanet6791]

why gibbs free energy curve goes downaward it the start?

[@nope3797]

Thank you sir 🙏

[@digitarola5191]

thank you very much

[@theamazingagares9043]

thank you very much it was really instructive

[@vincentlam6283]

Brilliant!!!!!!!

[@beyond_desi7719]

Really helpful

[@adelmohaned8205]

very very very thanks

[@siddharthpradhan9603]

Thanks

[@giancarlokuosmanen9723]

Still amazing @ 2024!

[@arariosoul840]

thanks alot .

[@aritram10]

Thanks a Lot Sir

[@yanalishkova1873]

Thank you ][=

[@chisechee874]

my brain

[@renzoandre5286]

You look like a very nice guy

[@pacific5811]

well, im fucked for my exam

[@danysikavya7327]

It's been two years! Hope It went quite well for you bro. I got one as well tomorrow

[@BobClemintime]

What determines which phase has the lowest overall free energy?