Solid CaCl2.6H2O and liquid water at 25 °C are mixed adiabatically in a continuous process to form a brine of 20 wt.% CaCl2. Determine the last temperature of brine solution formed. The specific heat of a 20 wt.% aqeous CaCl2 solution at 25 °C is 3.42 kJ/kg °C Molecular weights 11.98 and 18 g/mol, respectively. Solution Mixing ratio Heat of Solution (kJ) CaCl2/10 mol H2O -862.74 CaCl2/15 mol H2O -867.85 CaCl2/20 mol H2O -870.06 CaCl2/25 mol H2O -871.07 CaCl2/50 mol H2O -872.91 CaCl2/100 mol H2O -873.82 CaCl2/300 mol H2O -874.79 CaCl2/500 mol H2O -875.13 CaCl2/1000 mol H20 -875.54

Isopropanol, with 13 wt% water, can be dehydrated to obtain almost pure isopropanol at a 90% recovery by azeotropic distillation with benzene. When condensed, the overhead vapor from the col- umn forms two immiscible liquid phases. Use Table 2.4 with data in Perry's Handbook and the data below to compute the heat-transfer rate in Btu/h and kJ/h for the condenser. Water-Rich Organic-Rich Overhead Phase Phase Phase Vapor Liquid Liquid Temperature, °C 76 40 40 Pressure, bar 1.4 1.4 1.4 Flow rate, kg/h: Isopropanol 6,800 5,870 930 Water 2,350 1,790 560 Benzene 24,600 30 24,570

9.12 A 50 wt% Ni-50 wt% Cu alloy is slowly cooled from 1400°C (2550 F) to 1200°C (2190 F). (a) At what temperature does the first solid phase form? (b) What is the composition of this solid phase? (c) At what temperature does the liquid solidify? (d) What is the composition of this last remaining liquid phase?