What Do Subscript Variables Indicate in Thermodynamic Equations?

[strokebow]

Hi,

Example:

Maxwell Relation (thermoD)...


($\frac{∂μ}{∂T}$)$_{p,n}$ = - ($\frac{∂S}{∂n}$)$_{T,p}$

what does it mean having those subscript variables outside of the brackets.

thanks

 

[mfb]

They are kept constant in the process. For example, the left side is the change of µ if you change T, but keep p and n constant.

 

[Studiot]

post#2 of https://www.physicsforums.com/showthread.php?t=666011

gives an example of the use of this for deriving one of Maxwells relations

Have you studied partial differentiation?