Vapor pressure given boiling point and heat of vaporization?

[1MileCrash]

Homework Statement

What is the vapor pressure of benzene at 50.0 C? Benzene's boiling point is 80.1 C and its heat of vaporization is 31 kJ/mol

Homework Equations

The Attempt at a Solution

I don't want to be that guy who just says "I don't know" but.. All I know is that:

ln P = -(Hvap)/RT + C (and I don't know what C is besides "constant.")

and

ln(p1/p2) = Hvap/R (T1-T2/T1T2) but this relates the vapor pressure at different temperatures..

I am really not good at these applied things... any help is appreciated.

 

[Borek]

You are right about trying to use Clausius–Clapeyron relation. What is the definition of a boiling point?