• # question_answer 4) Calculate the work done in reversible isothermal expansion when 2 L of an ideal gas at a pressure of 10atm expands isothermally against 1 atm pressure to a final volume of 10 L.

$w=2.303nRT\,log\left( \frac{{{V}_{2}}}{{{V}_{1}}} \right)\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,......(i)$ $PV=nRT\,\,\,\,\,\,\,\,\,\,\,......(ii)$ From eqs. (i) and (ii) $w=2.303PV\,\log \left( \frac{{{V}_{2}}}{{{V}_{1}}} \right)$ $=2.303\times 1\times 10\log \left( \frac{10}{2} \right)$ $=16.1litre-atm=16.1\times 101.3J=1630.93J$ ${{w}_{\exp }}=-1630.93J$ $q=-{{w}_{\exp }}=1630.93J$