The common laboratory solvent diethyl ether (ether) is often used to purify subs
ID: 1005305 • Letter: T
Question
The common laboratory solvent diethyl ether (ether) is often used to purify substances dissolved in it. The vapor pressure of diethyl ether, CH3CH2OCH2CH3, is 463.6 mm Hg at 25 °C. In a laboratory experiment, students synthesized a new compound and found that when 24.82 grams of the compound were dissolved in 252.0 grams of diethyl ether, the vapor pressure of the solution was 451.5 mm Hg. The compound was also found to be nonvolatile and a nonelectrolyte. What is the molecular weight of this compound?
diethyl ether = CH3CH2OCH2CH3 = 74.12 g/mol
MW = ____g/mol
Explanation / Answer
(p0-p)/p0 = n1/n1+n2
(463.6-451.5)/463.6 = (24.82/x)/((24.82/x)+(252/74.12))
molecular weight of solute = 272.4 g/mol