# What is the pressure in atmospheres, if the pressure is reported to be 854*mm*Hg?

Apr 6, 2017

I do not know why we seem to be getting a lot of questions that quote pressures of $> 760 \cdot m m \cdot H g \ldots \ldots \ldots \ldots$
One atmosphere of pressure will support of column of mercury that is $760 \cdot m m$ high. And thus we can use a colume on mercury to measure pressures that ARE LESS than $1 \cdot a t m$, i.e $< 760 \cdot m m \cdot H g$.
Given your problem, I suppose we could state that 854*"Torr"-=(854*"mm Hg")/(760 *"mm Hg"*atm^-1)=1.12*atm. I really find the use of these units objectionable, because if you get a mercury spill in the lab, you have a major clean-up job, and guess who is going to do it?
And thus your question has not been consistently proposed. The pressure is LOWER at $1.12 \cdot a t m$; i.e. it is expanded not compressed. Would you review this problem?