# What is the total pressure if an anaesthetic gas is delivered at 330*mm*Hg pressure?

Nov 25, 2016

If an anaesthetic gas is administered, unless you are in a hyperbaric chamber (for instance after a diving emergency) the total pressure is $1 \cdot a t m$, i.e. enough to support a $760 \cdot m m \cdot H g$ column.
The sum of the individual partial pressures of whatever gases you are inhaling is thus $1 \cdot a t m$. On this basis, the partial pressure of oxygen is $430 \cdot m m \cdot H g$ $\cong 0.6 \cdot a t m$,
However, this question proposes that a total pressure of $760 \cdot m m \cdot H g \text{ (dioxygen)"+330*mm*Hg" (cyclopropane)}$ is administered. This is not the way that anaesthetic gases are administered; the total pressure must be atmospheric, and the individual partial pressures after they exit the regulator on the tank sum to one atmosphere.