Joule-Thomson effect

The Joule-Thomson effect is also known as the Joule-Kelvin effect.

Joule-Thomson coefficient

The Joule-Thomson coefficient is given by

${\mu }_{\mathrm{J}T}={\frac{\partial T}{\partial p}|}_H$

where T is the temperature, p is the pressure and H is the enthalpy.

In terms of heat capacities one has

${\mu }_{\mathrm{J}T}{C}_V=-{\frac{\partial E}{\partial V}|}_T$

and

${\mu }_{\mathrm{J}T}{C}_p=-{\frac{\partial H}{\partial p}|}_T$

In terms of the second virial coefficient at zero pressure one has

${\mu }_{\mathrm{J}T}=B_2-T\frac{d{B}_2}{dT}$

References

1. Thomas R. Rybolt "A virial treatment of the Joule and Joule-Thomson coefficients", Journal of Chemical Education 58 pp. 620-624 (1981)