If a sample of helium gas at 870 torr and 22 degrees C is allowed to expand from 23 L to 55 L without changing the temperature, what pressure will the helium gas exert?

1 Answer
May 25, 2018

Answer:

Well, for a start...the measurement of pressure is illegitimate...

Explanation:

We know that one atmosphere will support a column of mercury that is #760*mm# high. A mercury column is thus a good measure for pressures at #1*atm# or much LOWER than #1*atm#..

And so here #P=(870*mm*Hg)/(760*mm*Hg*atm^-1)=1.15*atm#.

And so #P_1V_1=P_2V_2#...and #P_2=(P_1V_1)/V_2#

#=(1.15*atmxx23*L)/(55*L)=0.479*atm-=363.8*mm*Hg#