Answer to Question #163619 in Physical Chemistry for Shubhangi Sawant

Question

One mole of an ideal gas expands reversibly from a volume of 5 dm^3 and temperature of 25 °C to a volume of 10 dm^3 and temperature of -23 °C. Calculate the entropy change accompanying the process. (Assume C v= 1.5R, R= Universal gas constant).

Answer 1

$\Delta$S = $\Delta$S_T + $\Delta$S_P = nC_pln(T₂ / T₁) + nRln(V₂ / V₁) = n(C_v + R)ln(T₂ / T₁) + nRln(V₂ / V₁) = 9.814ln(250 / 298) + 8.314ln(10 / 5) = 4.04 (J / K).

Answer: $\Delta$S = 4.04 (J / K)