Question

Consider the phase diagram below for a mixture of chloroform and methanol, looking at how the boiling point changes with composition at constant pressure. If you started with a solution that was Xchloroform = 0.1 at a temperature of 333 K, is it possible to use fractional distillation to purify this solution to nearly 100% chloroform? Approximately what concentration (in mole fraction) would you expect you could achieve through fractional distillation? Curves calculated by mod. UNIFAC (Dortmund) Temperature Minimum Azeotrope Mixture of Chloroform and Methanol 340 Constant Pressure P- 101.325 kPa 339 Pure boiling point of Methanol 338 337 336 Pure boiling point of Chloroform Vapor only (higher temperatures) 335 334 Vapor composition Dew point curve 333 332 331 330 329 328 Liquid composition Boiling point curve 327 326 Liquid only Azeotrope (lower temperatures) 325 324 0 0.1 Pure 0.2 0.3 0.5 Mole Fraction Chiloroform [molimol] 0.4 0.6 0.7 0.8 0.9 1 Pure Chloroform Methanol Coexistent phases Temperature [K]

Answer 1

SolGiven Phase digram Tempesatuse-Minimum Aaotsope Mixture of chlosofosm and Methanol 340 Consiant Poess Pure botling Point of Methano 339 PE l01.325 KPa 338 337 Pine botting 336 Point of Chlorofosm 3 35 Vapos only 334 333 3 32 vapor Composttion Deo Point 331 Curve 330 329 328 quid Composter on 327 Boiting Poins Cunve 326 Aacotsope 324 0.3 0 O.5 O.u O o.8 O. O.6 Pse Prpe Mole fisaction chloo-foom Methanol chlosefosm Coexistent phases Tempesatee Ck)

The phase dhagsamfo mrture chloso-form and Methanol. The boing point Changes coth Lomposition at Constant Poessuse The Stasted coth a Solution that oas - 0. at teP Of 333k chloofom foactional disti llation -to use Posible to pusfthis chloor fosm? Solution to nealy loo. No, It s not Possible -to oblain loo - Chlore-fosm Puse Theformaton of Oacotsopic mizture fure thes Sepesation et we Can not dh sti1la tion aetonal oppooximatly the gaph 65 to May be Pusity s T0 Mmole fracton Cas per Compasttion at 0geotopic Мay