Question

在573K时,将1mol Ne(可视为理想气体)从1000kpa经绝热可逆膨胀到100kpa.求Q,W,U,H

Answer 1

绝热,Q=0

r = Cp,m / Cv,m = (Cv,m+R)/Cv,m = (3/2 R +R)/ (3/2 R) = 5/3

T₁^r p₁^(1-r) = T₂^r p₂^(1-r)

解得 T₂ = 228 K

ΔU=W = n Cv,m (T₂ - T₁) = - 4302 J

ΔH = n Cp,m (T₂ - T₁) = (3/2R +R)(T₂-T₁) = - 7171 J