This quantity is conserved in an ideal Hampson–Linde cycle, which is used in the liquefaction of gases. At a constant value of this quantity, hydrogen, helium, and neon warm upon expansion because they have very small inversion temperatures. The differential for this quantity is equal to “T dS + V dp” when particle number is held constant. Throttling processes conserve this quantity via the Joule–Thomson effect. (10[1])In the thermodynamic square, this quantity is the only non-energy potential. Along with energy, the Born–Haber cycle calculates a “lattice” (10[1])version of this quantity from (10[1])Hess’s law. This quantity, equal to the sum of the internal energy plus pressure times volume, is negative for exothermic processes. For 10 points, name this state function denoted H. ■END■