Question

Given a gas under `600*"mm Hg"` pressure, and at `303.15*K` temperature, that occupies a volume of `2.02*L`, what volume will it occupy at `273.15*K` temperature, under `750*"mm Hg"` pressure?

Answer 1

Well, the current definition of `"STP"` is.... a temperature of `273.15*K` and a pressure of exactly `10^5*Pa` `(100*kPa, 1*"bar")`.

Explanation:

And `1*"bar"-=(1*"bar")/(1.01325*atm*"bar"^-1)=0.987*atm`

I do all this rigmarole BECAUSE I know that `1*atm` will support a column of mercury that is `760*mm` high...........

And hence in terms of the length of a mercury column, `1*"bar"-=760*mm*Hg*atm^-1xx0.987*atm=750.0*mm*Hg`

`(P_1V_1)/T_1=(P_2V_2)/T_2`

We want `V_2=(P_1V_1)/T_1xxT_2/P_2`

`(600.0*mm*Hgxx2.02*L)/(303.15*K)xx(273.15*K)/(750*mm*Hg)`

`~=1.5*L`