\(\mathrm{W}=-\mathrm{P}_{\mathrm{ext}} \Delta \mathrm{V}\)
\(=-2.5[4.5-2.5]=-5 \,\mathrm{L}\; atm\)
\(=-5 \times 101.3 \,\mathrm{J}=-505 \,\mathrm{J}\)
Since system is well insulated \(q=0\)
By First Law of Thermodynamic \(\Delta \mathrm{E}=\mathrm{q}+\mathrm{W}\)
\(\Delta E=W=-505\;J\)
($\Delta H$ અને $\Delta S$ તાપમાન સાથે બદલાતા નથી તેમ ધારો)