Four moles of hydrogen, two moles of helium and one mole of water vapour form an ideal gas mixture. [C_v . for hydrogen = 5 2 R, C_v for helium = 3 2 R, C_v for water vapour .=3 R ] What is the molar specific heat at constant pressure of the mixture?

Step-by-step solution

C_p=C_v+R C _ p for hydrogen, C _ p ₁ = 7 2 R C _ p for helium, C _ p ₂ = 5 2 R C _ p for water vapour, C _ p ₃ =4 R Also, n ₁=4, n ₂=2 and n ₃=1 aligned C_p of mixture & = n₁ C_ p₁ +n₂ C_ p₂ +n₃ C_ p₃ n₁+n₂+n₃ & = 4 7 R 2 +2 5 R 2 +4 R 4+2+1 & = 14 R+5 R+4 R 7 = 23 R 7 aligned