Calculate the vapor pressure of a solution prepared by dissolving 0.500 mol of a non-volatile solute in 275 g of hexane (ℳ = 86.18 g/mol) at 49.6°C. P°_hexane = 400.0 torr at 49.6°C. A)54 torr B)154 torr C)246 torr D)346 torr E)400. torr

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The vapor pressure of the solution can be calculated using Raoult's Law, which states that the vapor pressure of a solution is directly proportional to the mole fraction of the solvent. First, calculate the moles of hexane (solvent):$$ \text{Moles of hexane} = \frac{\text{Mass of hexane}}{\text{Molar mass of hexane}} = \frac{275 \, \text{g}}{86.18 \, \text{g/mol}} = 3.19 \, \text{mol} $$Next, calculate the mole fraction of hexane:$$ \text{Mole fraction of hexane} = \frac{\text{Moles of hexane}}{\text{Moles of hexane} + \text{Moles of solute}} = \frac{3.19}{3.19 + 0.500} = \frac{3.19}{3.69} = 0.865 $$Finally, apply Raoult's Law to find the vapor pressure of the solution:$$ \text{Vapor pressure of solution} = \text{Mole fraction of hexane} \times \text{Vapor pressure of pure hexane} = 0.865 \times 400.0 \, \text{torr} = 346 \, \text{torr} $$

Calculate the Vapor Pressure of a Solution Prepared by Dissolving