An ideal monoatomic gas undergoes a reversible process: P/V = constant, from (2 bar, 273 K) to 4 bar — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

For P/V = constant, PV^-1 = constant. This is a polytropic process with polytropic index x = -1. The work done in a polytropic process is w = nR * dT / (x - 1) = nR * dT / (-1 - 1) = -0.5 * nR * dT. For a monoatomic gas, $C_v$ = 1.5 R. Δ U = n * $C_v$ * dT = 1.5 * nR * dT. Thus, Δ U / w = (1.5 * nR * dT) / (-0.5 * nR * dT) = -3.0.