A gas at 4 atm and 300 K in a 5 L container is compressed isothermally to 2 L. What is the work done on the gas? ( R = 8
**Zeroth law of thermodynamics** if two systems A and B each in thermal equilibrium with third C, then A and B in equilibrium with each other, defines temperature as property that is same for systems in thermal equilibrium, basis for thermometer, temperature scale, thermal equilibrium means no net heat flow, same temperature. Isothermal: W = μ R T ln((V₂)/(V₁)) . P₁ V₁ = μ R T ⇒ 4 × 5 = μ × 8.3 × 300 ⇒ μ = (20)/(2490) ≈ 0.008 mol . W = 0.008 × 8.3 × 300 × ln((2)/(5)) = 19.92 × (-0.916) ≈ -18.25 J (work by gas negative). Work
Ref: NCERT > Physics Book > Thermodynamics > Zeroth Law Thermal Equilibrium and Quasi-static
