Evaporative equilibrium equation?

I have a question where I'm given the enthalpy of vaporization at a certain temperature. Then I'm asked how much heat would be required to vaporize 1.00 L of the given liquid at a certain temperature if it's density is given.

The values that i can't seem to find are the 2 vapor pressures. I think i have to use the density and some other values to find the vapor pressures so i can plug them into the equation

I haven' included any of the actual values because i don't need anyone to solve this for me, i just need to know how to attain a certain value.

Thank you in advance for your help