Identify the correct expression for the work done (W) by n moles of an ideal gas when it expands isothermally at temperature T from an initial volume Vi to a final volume Vf.
a) W=nRT(ViVf−Vi)
b) W=nRTlnViVf
c) W=nRTlnVfVi
d) W=23nRTlnViVf