sir, thanks for all the efforts in making us to understand the subject., it would be great if you teach us more on gibbs free energy concept and equilibrium diagrams.
Sir, I would like to pursue a Ph.D. under you... or either an internship at least...😀😀..you made me fall in love with this subject of material science ... Thanks a lot.
@@introductiontomaterialsscience never seen such a responsive professor ever on youtube....very humble and full of knowledge....best wishes to you....live long and keep inspiring us
Hi sir ,here driving force is much similar to available energy of thermodynamics Wmax=Q(1-T°/T) where Wmax Is max available energy(Heat) from temp T with respect to deadstate T° ,which is atm temp
It is actually a matter of definition. You can define it either way. Ususally any difference is defined as final minus initial. So for freezing final is solid and initial liquid. So in this definition delta G is negative. So in the critical radius formula a minus sign comes to make the radius positive. If you define the other way delta G is positive and the critical radius formula will also not require the minus sign.
Sir when assuming deltaH and deltaT independent of Temperature why do we mention DeltaSm which means that value of entropy at melting point. Please correct me if I am wrong.
We are assuming Delta H and Delta S to be independent of T and have their values equal to those at the melting point. Thus we assume Delta H=Delta H_m and Delta S=Delta S_m.
Under equilibrium conditions, the liquid will freeze at Tm and no liquid can exist below Tm. But it is possible for liquid to exist below Tm under nonequilibrium conditions. This liquid is unstable and will eventually freeze. It is called undercooled liquid.
@@rajeshprasad101 It would be good sir if you monetize your channel as your channel already meet all the necessary requirements. Sir, I've one request. I want to do intern under your guidance . If any , please give me an opportunity.Thank you !
It is Gibbs function defined as G=H-TS where H is enthalpy, T absolute temperature and S entropy. At constant T and pressure P the equilibrium state of a system is characterized by a minimum of G.
It is defined from the equilibrium conditions at constant temperature and pressure. G = H - TS = 0 (at const T and P equilibrium) if you substitute for H and S based on first law and second law definitions you derive that G represents the maximum amount of reversible work done at constan T and P.
@@pailasaisravan5423 These will not be independent of temperature in general. But for small undercoolings the variation is small and they can be considered constant. The assumption simplifies the analysis.
Sir pursued his btech from IIT BHU and later his ME from IISC Bangalore and then he completed his Phd from Cambridge university, sir is awarded Teaching excellency award in 2012 by IIT Delhi and also received A.A. Krishnan Gold Medal for his M.E. thesis at the Indian Institute of Science, Bangalore, sir is currently a faculty at IIT Delhi(Unsure as of now), so please think before yall speak, he is humble enough to solve all our queries and provide this course free of cost.
I love 💕 the method of teaching.
I like the way in which you are teach 👍🏻
sir you are great, app hi ek esa teacher hai jinka lecture suru hone se pahle hi viswas ho jata hai ab to me is topic ko samaz hi haunga
thank you for such a wonderful explanation
sir, thanks for all the efforts in making us to understand the subject.,
it would be great if you teach us more on gibbs free energy concept and equilibrium diagrams.
thank you professor
Sir, I would like to pursue a Ph.D. under you... or either an internship at least...😀😀..you made me fall in love with this subject of material science ...
Thanks a lot.
😀
@@introductiontomaterialsscience never seen such a responsive professor ever on youtube....very humble and full of knowledge....best wishes to you....live long and keep inspiring us
Saviour.
Hi sir ,here driving force is much similar to available energy of thermodynamics Wmax=Q(1-T°/T) where Wmax Is max available energy(Heat) from temp T with respect to deadstate T° ,which is atm temp
I have a dumb question? What do we mean by free energy? Where does it come from ? 🤔
It is not a dumb question. It is a rather deep question, and one has to go into a lot of thermodynamics to appreciate it fully.
At 5.00, If G(alpha) is greater than G (beta) . Then Driving force ( ΔG=Gβ-Gα) could be in negative.??? Is it possible?? Correct me if I'm wrong.
I think driving force should be always positive
Sir, for freezing it should be: delta G = G(Liquid) -- G( Solid) at 9:01 but you have written opposite to that. Please resolve my doubt....
It is actually a matter of definition. You can define it either way. Ususally any difference is defined as final minus initial. So for freezing final is solid and initial liquid. So in this definition delta G is negative. So in the critical radius formula a minus sign comes to make the radius positive. If you define the other way delta G is positive and the critical radius formula will also not require the minus sign.
@@introductiontomaterialsscience Thank you sir for explanation. Your lectures are very helpful...
Sir when assuming deltaH and deltaT independent of Temperature why do we mention DeltaSm which means that value of entropy at melting point. Please correct me if I am wrong.
We are assuming Delta H and Delta S to be independent of T and have their values equal to those at the melting point. Thus we assume Delta H=Delta H_m and Delta S=Delta S_m.
👍
sir,...at 7:36 T is Less than Tm. what is the meaning of liquid below freezing temperature(Tm)...below Tm everything is solid???? clear my doubt sir
Under equilibrium conditions, the liquid will freeze at Tm and no liquid can exist below Tm. But it is possible for liquid to exist below Tm under nonequilibrium conditions. This liquid is unstable and will eventually freeze. It is called undercooled liquid.
Please correct the driving force at 8:11. I think it should be Gs(T)-Gl(T).....
Correct me if I'm wrong
Yes you r right.
correct he wrote by mistake but corrected it in subsequent slide
Sir, did you monetize your channel.
No, as you can see from the absence of any ads.
@@rajeshprasad101 It would be good sir if you monetize your channel as your channel already meet all the necessary requirements.
Sir, I've one request. I want to do intern under your guidance . If any , please give me an opportunity.Thank you !
what is free energy mean??
It is Gibbs function defined as G=H-TS where H is enthalpy, T absolute temperature and S entropy. At constant T and pressure P the equilibrium state of a system is characterized by a minimum of G.
It is defined from the equilibrium conditions at constant temperature and pressure. G = H - TS = 0 (at const T and P equilibrium) if you substitute for H and S based on first law and second law definitions you derive that G represents the maximum amount of reversible work done at constan T and P.
sir what is the logic behind that assumption and why we have to assume ???
Could you please be specific about what assumptions you are referring to?
@@introductiontomaterialsscience delta h and delta s are independent of temperature at 12.11
@@pailasaisravan5423 These will not be independent of temperature in general. But for small undercoolings the variation is small and they can be considered constant. The assumption simplifies the analysis.
sir you are like a slow voice
sir you are a mad
😀
@ subham Singh dhoni 9225....Are u from private engineering college and was not JEE aspirant😕? ...
Sir pursued his btech from IIT BHU and later his ME from IISC Bangalore and then he completed his Phd from Cambridge university, sir is awarded Teaching excellency award in 2012 by IIT Delhi and also received A.A. Krishnan Gold Medal for his M.E. thesis at the Indian Institute of Science, Bangalore, sir is currently a faculty at IIT Delhi(Unsure as of now), so please think before yall speak, he is humble enough to solve all our queries and provide this course free of cost.
sir your voice is slow please try again
?
@@Kal_Al_Thor sus