# First Challenge Problems

Problem Set 1. Vapor Liquid Equilibria

Part a) Determine the Px curve for a mixture of dimethyl ether and propylene at -20 °C (253.15 K)with explicit pressures for x=0, 0.2, 0.4, 0.6, 0.8, 1.0 and the pressure at 20 °C (293.15 K) for x=0.5

Part b) Determine the pressure and composition of the azeotropic point for a mixture of nitroethane and propylene glycol monomethyl ether at 80 °C (353.15 K)and at 40 °C (313.15 K), and the bubble point pressure for x=0.2 (nitroethane) and x=0.5

Problem Set 2. Prediction of density

The task is to determine the density of the following fluids at the specified conditions. Benchmarks are provided for part a, water.

 part # system State Point 1 State Point 2 a water 0.1 MPa, 293 K (998.24 kg/m3) 2.0 MPa, 423 K (918.01 kg/m3) b Cyclohexane 0.1 MPa, 300 K 20 MPa, 400 K c Isopropanol 0.1 MPa, 298.15 K 5 MPa, 400 K d Diethanol amine 0.1 MPa, 330 K 5 MPa, 400 K e 1,2,3-trichloropropane 0.1 MPa, 290 K 1.5 MPa, 400 K f Triethylene glycol 0.1 MPa, 310 K 2 MPa, 280 K g Pyridine 0.1 MPa, 298 K 10 MPa, 375 K h Water + choline chloride (Aqueous choline chloride) 0.1 MPa, 298 K, 20% choline Cl by weight 1 MPa, 305 K, 10% choline Cl by weight i Water + methanol (50:50 by mass fraction) 0.1 MPa, 325 K 10 MPa, 400 K

Problem Set 3. Prediction of Viscosity

The task is to determine the shear viscosity of the following fluids at the specified conditions.

 part # system State Point 1 a N-nonane 0.1 MPa, 300 K b Isopropanol 0.1 MPa, 300 K c N-nonane + Isopropanol (0.5 mole fraction) 0.1 MPa, 300 K d N-nonane + Isopropanol (0.75 mole fraction isopropanol) 0.1 MPa, 300 K