Practice question

**Isochoric process** constant volume ΔV=0, work W=0, first law ΔU = Q, all heat goes to internal energy, P/T = constant from ideal gas law P V = n R T at constant V, pressure proportional to temperature, P₁/T₁ = P₂/T₂, e.g., heating gas in rigid container pressure rises proportionally to T. First Law: Δ Q = Δ U + Δ W . Δ Q = -760 (heat released), Δ W = 240 (work by system). -760 = Δ U + 240 ⇒ Δ U = -760 - 240 = -1000 J . Using first law ΔU = Q - W, W = ∫ P