Question

1. 1200 mL aqueous solution of 45 g of ethylene glycol and 80 g of sucrose were prepared with a density of 1.37 g/mL. Assume that the solution behaves ideally. Notes: The vapor pressures of water and ethylene glycol at 20 °C are 17.54 torr and 0.06 torr, respectively, and Kb and Kf of water are 0.51 K/m and 1.86 K/m, at 25 °C respectively. a. What is the freezing point of this solution? b. What is the vapor pressure, in torr, of this solution at 20 °C? c. What is the osmotic pressure, in atm, of this solution at 25°C and 0 °C? d. What is the mass percent (m/m) % of sucrose in this solution?

Answer 1

given weight of ethylene glycol = u5g molar mass of ethylene glycol = 62.07 0 m moly Ethylene glycol= given mans molqy mars = -0.725 mol 45 62.07 mol 62.0 given weight of sucrose = 80g mokro man mol surobe = 342 3 9 mol 808 = 0.234 mol 342-3 g molt Total mol = molg etylene glycol + mol y sucuose = 0: 725+0-234 = 0.959 mol Total volume J 801 = 1200ml density = 1.320 mm mang solution density xVolume = 1200190 X 1.37gr = 16449 many solvent = = mang solusim- mang solute (Ethylene glycol + sucrose) 16449 - 1259 = 15199 molality of sol = Total moly solute weight of soverty lig: oooky) 0.959 mol = 0.00063 m 1519 kg.

CH 074 = m XK me molality y sol kg = molal depresion constant OTH = depremim in Freening point AT = 0.00063 x 186 K DTH = 0.0012 K = 0.00123 Oły = Tį (solvent) - Tt ( solution) 0.0012°C = 0.0°C - +(solution) -0.0012°c = Tflsolulim) Freezing point g 8013 -0.0012°c mol, Watu given mass Molly man 15197 = 84.34 Mol - 18.01g mort mole frachium solute = mol soluto Total mol 0.0112 0.959 mol = 84.34 mol + 0.959 mol mole fraction solute = 0.0112 Relative lowering og vapour prenure - por las = xa po XB = mol pracho y solute 17.54 toor- pool 0.0112 17. sy toor 0 196 hor = 1n.su torr-Pool +11.34 toor = tpool

Vapour Solution of solution = 17:34 toro O Mohic prepure (T) = CRT (= concentration of sol R = gas constant T = Temprature TCK) = 1 + 2 13:15 = 25+27315 = 298.15 concentration & sol= mol Volymey solly = 0.799M 0.959 mol - 1. 2L When Tempe 2546 = 298.15K π = 0.799 mot X 0.0821 Xanth X 298.15K monk T= 19.6 ahm Osomoric Prenure : 19.6 am Whene temp = 0º = 273.15k -0.799 270) * 0.0821 Xalm X 2731155 mol. = 17.92 ahm o so moric Pressure = 17.92 ahm man percent (min) = many suco de xloo Total mass of sol 809_x100 Touag = 4.871.