Final answer:
To calculate the vapor pressure at 25°C of a solution containing 55.8g ethylene glycol and 274.8g water, we need to calculate the mole fraction of water. Using Raoult's law, the vapor pressure of the solution is found to be 22.48 torr.
Step-by-step explanation:
To calculate the vapor pressure of the solution, we need to know the mole fraction of water. We can calculate the number of moles of both ethylene glycol (EG) and water present in the solution.
Given that the solution contains 55.8g of ethylene glycol and 274.8g of water, we can calculate the moles of each component.
The moles of ethylene glycol (EG) can be calculated using its molar mass (62.07 g/mol):
Moles of EG = mass of EG / molar mass of EG = 55.8g / 62.07 g/mol = 0.899 mol
The moles of water can be calculated using its molar mass (18.015 g/mol):
Moles of water = mass of water / molar mass of water = 274.8g / 18.015 g/mol = 15.23 mol
Now, we can calculate the mole fraction of water:
Mole fraction of water = Moles of water / (Moles of EG + Moles of water) = 15.23 mol / (0.899 mol + 15.23 mol) = 0.944
The vapor pressure of the solution can be calculated using Raoult's law:
Vapor pressure of solution = Mole fraction of water * Vapor pressure of pure water
Vapor pressure of solution = 0.944 * 23.8 torr = 22.48 torr