The work done (w) during the expansion of a gas against a constant external pressure (pext) is given by the formula:
w=−pextΔV=−pext(Vf−Vi)
Given:
Initial volume, Vi=4 dm3=4 L (since 1 dm3=1 L)
Final volume, Vf=6 dm3=6 L
External pressure, pext=3 atm
Substituting the values:
w=−3 atm×(6 L−4 L)=−3×2=−6 L atm
To convert the work done into Joules, we use the conversion factor 1 L atm=101.325 J:
w=−6 L atm×101.325 J/L atm=−607.95 J≈−608 J.