Glycerin (C3H8O3) is a nonvolatile liquid. What is the vapor pressure of a solution made by adding 180. g of glycerin to 321 mL of H2O at 39.8°C? The vapor pressure of pure water at 39.8°C is 54.74 torr and its density is 0.992 g/cm3.

To find the vapor pressure of the solution, we need to consider the vapor pressure of water and the effect of adding glycerin.

First, let's find the mole fraction of water in the solution.

1. Calculate the number of moles of glycerin:
- Given mass of glycerin = 180 g
- Molar mass of glycerin = 92.09 g/mol (from periodic table)
- Moles of glycerin = mass / molar mass = 180 g / 92.09 g/mol

2. Calculate the density of water:
- Given volume of water = 321 mL
- Convert mL to cm3: 321 mL x 1 cm3 / 1 mL = 321 cm3
- Density of water = 0.992 g/cm3

3. Calculate the mass of water:
- Mass of water = density x volume = 0.992 g/cm3 x 321 cm3

4. Calculate the number of moles of water:
- Molar mass of water = 18.02 g/mol (from periodic table)
- Moles of water = mass / molar mass

5. Calculate the mole fraction of water:
- Mole fraction = moles of water / (moles of water + moles of glycerin)

Next, we need to consider Raoult's Law to find the vapor pressure of the solution.

Raoult's Law states that the vapor pressure of a solution is equal to the vapor pressure of the pure solvent multiplied by its mole fraction in the solution.

6. Calculate the vapor pressure of the solution:
- Given vapor pressure of pure water = 54.74 torr
- Vapor pressure of the solution = mole fraction of water x vapor pressure of pure water

Finally, we can substitute the values into the equation to find the vapor pressure of the solution:

Vapor pressure of the solution = mole fraction of water x vapor pressure of pure water

By following these steps, you should be able to find the vapor pressure of the solution made by adding glycerin to water.