- #1
leah3000
- 43
- 0
Homework Statement
A gas expands in volume from 26.7mL to 89.3mL at constant temperature. Calculate the work done (in joule) if the gas expands:
i) against a vacuum
ii) against constant pressure of 1.5atm
iii) against a constant pressure of 2.8
Homework Equations
w= -PdV
gas expands at constant temperature= isothemic expansion
The Attempt at a Solution
i) I'm not sure about this part
ii) 1atm= 1.013x10^5 Pa
P= 1.5x 1.013x10^5 = 151950 Pa
I converted ml to m^3 (am i supposed to do this?)
26.7/ 1x10^6 = 2.67x10^-5 m^3
8.93/ 1x10^6 = 8.93x10^-5 m^3
w= -PdV
w= - (151950)x (8.93x10^-5 -2.67x10^-5)
w= -9.512 J
iii) I did the same working for this part as above
P= 2.8 x 1.013x10^5
P= 283640 Pa
w= - (283640) x (8.93x10^-5 -2.67x10^-5)
w= -17.756 J
am I doing this correct? or do I use the equation ln V2/V1 P ?