Question

A sample of fluorine gas exerts a pressure of 925 torr. When the pressure is changed to 1.50atm, it condenses to 250ml. what was the original volume ?

Answer 1

Again an unreasonable problem....

Explanation:

`760*"Torr"-=760*mm*Hg-=1*atm`

You do NOT use `mm*Hg` to measure pressures over one atmosphere. Why not? Because you will probably get mercury all over the lab, where it is a major safety hazard, which contract cleaners (rightly) would not touch. The question has been set by someone whose has NEVER used a manometer, and who never has cleaned up a mercury spill.

Here, we gots...`(925*"Torr")/(760*"Torr"*atm^-1)=1.22*atm`...the question should have quoted these units..not these whack mercury units.

Now at constant temperature...`P_1V_1=P_2V_2`...which is old Boyle's Law...

`V_1=(P_2V_2)/P_1=(1.50*atmxx250*mL)/(1.22*atm)=307.4*mL.`

Reasonably, the volume has INCREASED under these new conditions of REDUCED pressure....