An ideal-gas mixture consists of 60 percent helium and 40 percent argon gases by mass. The mixture

Question:

An ideal-gas mixture consists of 60 percent helium and 40 percent argon gases by mass. The mixture is now expanded isentropically in a turbine from 400oC and 1.2 MPa to a pressure of 200 kPa. The mixture temperature at turbine exit is
(a) 56oC
(b) 195oC
(c) 130oC
(d) 112oC
(e) 400oC