General Chemistry

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Calculation: Vapor Pressure of a Solution using Raoult's Law


Calculate the vapor pressure (in torr) at 20 °C for a solution of 18.2 g of table sugar (sucrose, molar mass = 342.3 g/mol) dissolved in 0.0550 L of water.

At 20 °C, the vapor pressure of water is 17.5 torr and the density of water is 0.9982 g/mL.

Hint: Use Raoult's law below.

$${P}_{soln} = {\chi}_{{H}_{2}O} {P}_{solvent}^{°}$$