A "Maxwell Relation" is a thermodynamic identity relating partial derivatives of state variables. These relationships can be derived using the fact that taking two mixed partial derivatives of a function does not depend on the order. ardy = mar. As an example, we know that OF OF av = -P =- S (1) Taking the T derivative (with V fixed) of the first equation gives OF OF av OTav (2) And taking the V derivative (with T fixed) of the second equation gives OF S avaT (3) Equations (2) and (3) must be equal (since the order of mixed partial derivatives doesn't matter) we have derived a Maxwell relation: OP AT (4) Question: Using the enthalpy H = U + PV, its differential dH, and the laws of thermodynamics, derive a Maxwell relation ap (5) S