Practice: How many grams of glucose, C6H12O6, must be added to 515.0 g of water to give a solution with a vapor pressure of 13.2 torr at 20.0ºC? The vapor pressure of pure water at 20.0ºC is 17.5 torr.
Vapor Pressure is the pressure exerted by a gas at equilibrium with its liquid phase at a specific temperature in a closed system.
Concept #1: Vapor Pressure Lowering
Example #1: Calculate the vapor pressure (in torr) of a solution containing 53.7 g Cd(NO3)2 (MW: 236.43 g/mol) in 155 g of water at 30.0ºC. The vapor pressure of pure water at this temperature is 131.8 torr.
Practice: How many grams of glucose, C6H12O6, must be added to 515.0 g of water to give a solution with a vapor pressure of 13.2 torr at 20.0ºC? The vapor pressure of pure water at 20.0ºC is 17.5 torr.
Practice: Determine the vapor pressure lowering associated with 1.32 m C6H12O6 solution (MW: 180.156 g/mol) at 25°C. The vapor pressure of pure water at 25°C is 23.8 torr.
Practice: The vapor pressure of water at 100.0ºC is 0.720 atm. Determine the mass percent of iron (II) chloride, FeCl2, needed to reduce its vapor pressure to 0.655 atm. (MW of FeCl2 is 126.756 g/mol)
