A 150.0 mL sample of an aqueous solution at 25 °C contains 15.2 mg of an unknown nonelectrolyte compound. If the solution has an osmotic pressure of 8.44 Torr, what is the molar mass of the unknown compound? A) 223 g mol^-1 B) 294 g mol^-1 C) 341 g mol^-1 D) 448 g mol^-1 E) 195 g mol^-1

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Quizplus · Accepted Answer

The correct answer is A because the molar mass of the unknown compound can be calculated using the formula:Molar mass = (Mass of solute / Volume of solution) * (RT / Osmotic pressure)where:Mass of solute = 15.2 mg = 0.0152 gVolume of solution = 150.0 mL = 0.1500 LR = 0.0821 L atm / (mol K)T = 25 °C = 298 KOsmotic pressure = 8.44 Torr = 0.0111 atmSubstituting these values into the formula, we get:Molar mass = (0.0152 g / 0.1500 L) * (0.0821 L atm / (mol K) * 298 K / 0.0111 atm)= 223 g mol^-1

A 1500 ML Sample of an Aqueous Solution at 25 °C