Question

Question 41 5 pts What is the change in vapor pressure when 52.9 g of ethylene glycol (molar mass 62 g/mol, nonelectrolyte) is added to 800 mL of H2O at 52.0°C. The vapor pressure of pure H20 at 52.0°C is 102.1 torr. The density of H2O at 52.0°C is 0.987g/mL. O 0.124 Torr 4.50 Torr 1.95 Torr 3.00 Torr

Answer 1

0-41 Vapour pressure of solution & Roults Law - When a non-volatile, non-electrolyte solute is dissolved in a soly ent to produce a Solution, the vapour pressure of solution decreases than the pure solvent. This can be expressed by Roulty law, p=x, p p=vapoure pressure ot pure Solvent vapourpressure of solution Xi = mole fractionat = nithe ; his moles of soment haa moles of solute Mass of ethylene glycol (solute) 52.9 g sholar mass of ethylene glycol (M2) = 62 glmal : moles of ethylene gly ^2) = 52.9 g 62 g mae ) اما = 0.853 2mol mass of dater solvent) (w.) = 800 m2 x 0.987%/m - (density - mass same = 789.6 g molar mass of water (Mi) = 18 g/mol :. Moles of water (n.) = - 7 8 9.6 g z 43.866 mol 18 g/mol Nod, mole fraction of Water 4) = h it ne vapour pressure of pure pater )= 102.1 forr. 43.866 431866 +0 8582 According to Routts Law, " Pad, p → P. 102.1 x / 43,866 (43.8687018632 ) 9 p 100.153 Vapour pressure of solution - 100.153 to Chang in vapour pressure =(po-P) = ( 102.1- 100.153 ) torr Answer- & 1.95 torr = 1.9464 for