Question

The common laboratory solvent ethanol is often used to purify substances dissolved in it. The vapor pressure of ethanol, CH2CH,OH, is 54.68 mm Hg at 25 °C In a laboratory experiment, students synthesized a new compound and found that when 35.52 grams of the compound were dissolved in 246.7 grams of ethanol, the vapor pressure of the solution was 53.38 mm Hg. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight of this compound? ethanol 3D CHCH,ОH — 46.07 g/mol. MW g/mol Retry Entire Group Submit Answer 9 more group attempts remaining

Answer 1

Ans :-

Molecular mass of the Solute (MW) = 272.62 g/mol

Explanation :-

Sol:>. By the definition of Relative Lowegung in vapower preterie : Ps NA Here, PO4 = va power pressure of solvent (ethanol) = 54.68 mm Hg Ps = vapour pressure of solution - 53.38 mm Hg no = number of moles of solute Given mass # solute Guam molar mass of solute (Mg) 35.529 MB na = number of moles of Solvent (ethanol) Given mass o ethanol Ciram molar mars of ethanol = 246.79 46.079/mol = 5.35 mol Substitute these values in equation 0, we have 54,68 mm Hg - 53,38 mm Hg = 35.529 53.38 mm Hg MB X 5.35 mol → Mg = 35.529 x 53.38 mm Ha 5.35 mol x 1.3 mmHq → MB = 272.62 g/mol Hence, MW= 272