The work done in the isothermal reversible expansion of argon gas at from 4 l to 16 l was equal to 4 — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

Work done $W = nRT \ln(V_2/V_1)$. Substituting values: $4200 = n \times 2\text{ cal/K-mol} \times 300\text{ K} \times \ln(16/4)$. $4200 = n \times 600 \times 1.4 \implies 4200 = 840 n \implies n = 5\text{ moles}$. Mass of Ar $= 5\text{ moles} \times 40\text{ g/mol} = 200.0\text{ g}$.