Liquid helium and liquid nitrogen are both used as coolants; He(e) boils at 4.21 K, and N 2 (e) boils at 77.35 K. The specific heat of liquid helium near its boiling point is 4.25 J K -1 g -1 , and...

Liquid helium and liquid nitrogen are both used as coolants; He(e) boils at 4.21 K, and N₂(e) boils at 77.35 K. The specific heat of liquid helium near its boiling point is 4.25 J K^-1g^-1, and the specific heat of liquid nitrogen near
its boiling point is 1.95 J K^-1g^-1. The enthalpy of vaporization of He(e) is 25.1 J g^-1, and the enthalpy of vaporization of N₂(e) is 200.3 J g^-1(these data are calculated from the values in Appendix F). Discuss which liquid is the
better coolant (on a per-gram basis) near its boiling point and which is better at its boiling point.