What is the vapor pressure in mm Hg of a solution prepared by dissolving 5.00 g of benzoic acid (C7H6O2) in 100.00 g of ethyl alcohol (C2H6O) at 35 °C? The vapor pressure of pure ethyl alcohol at 35 °C is 100.5 mm Hg.

Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid or solid phase at a given temperature. It reflects the tendency of particles to escape from the liquid phase into the vapor phase. The vapor pressure of a solution is typically lower than that of the pure solvent due to the presence of solute particles, which disrupt the solvent's ability to evaporate.

Raoult's Law states that the vapor pressure of a solvent in a solution is directly proportional to the mole fraction of the solvent in the solution. This law helps predict how the addition of a solute affects the vapor pressure of the solvent. It is mathematically expressed as P_solution = X_solvent * P°_solvent, where P_solution is the vapor pressure of the solution, X_solvent is the mole fraction of the solvent, and P°_solvent is the vapor pressure of the pure solvent.

Mole fraction is a way of expressing the concentration of a component in a mixture. It is calculated as the number of moles of a component divided by the total number of moles of all components in the mixture. In the context of vapor pressure calculations, the mole fraction of the solvent is crucial for applying Raoult's Law to determine the vapor pressure of the solution.