Problem No: $5$ A salesman for The Fabulous Co$.$ offered our surgical team a novel type of

a surgical tool that he claims to cut painlessly. It works by blowing a very cold air onto the tissue

to be cut. Tissue freezes, feeling disappears, and there is no need for anesthetics. "Fabulous!!"

He says that the heart of the device is a Hilsch tube, a device that splits a stream of high$-$pressure

air $(P_1=\frac{1\mathrm{.}5}{b}ar,T_1=27C)$ into two equimolar streams, one how and the other cold, both at

pressures of $1$ bar. The cold stream side is then blown at the scalpel blade.

The salesman claims that the cold air is at $-123C.$ I don't believe that the air could get that cold

with such a simple device. Would you please determine whether his claims violate the laws of

thermodynamics?