The vapor pressure of water at 45.0 °C is 71.93 mmHg.What is the vapor pressure of water over a solution prepared from 75.0 g of citric acid (C₆H₈O₇)in 0.420 kg of water at this temperature? A)1.22 mmHg B)42.3 mmHg C)43.0 mmHg D)70.7 mmHg E)73.2 mmHg

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Quizplus · Accepted Answer

The vapor pressure of a solution is calculated using Raoult's Law: P_solution = X_solvent * P_pure solvent. First, calculate the mole fraction of water (solvent). Moles of citric acid = 75.0 g / 192.12 g/mol = 0.390 moles. Moles of water = 420 g / 18.015 g/mol = 23.31 moles. Mole fraction of water = 23.31 / (23.31 + 0.390) = 0.9836. Vapor pressure of solution = 0.9836 * 71.93 mmHg = 70.7 mmHg.

The Vapor Pressure of Water at 45