Practice question

**First law applications** for isobaric W = P ΔV, Q = n C_p ΔT, ΔU = n C_v ΔT, for isothermal ideal gas ΔU=0 Q=W=n R T ln(V₂/V₁), for adiabatic Q=0 W= -ΔU = (P₁V₁ - P₂V₂)/(γ-1), for isochoric W=0 ΔU=Q=n C_v ΔT, enabling calculation of Q,W,ΔU for any process. Isothermal: Δ U = 0 , Δ Q = Δ W = μ R T ln((V₂)/(V₁)) . μ = 0.2 , T = 350 , V₂ = 10 , V₁ = 4 . Δ Q = 0.2 × 8.3 × 350 × ln((10)/(4)) = 581 × 0.916 ≈ 532 J . Using first law ΔU