Vapor Pressure

[Zingerburger7]

The enthalpy of vaporization of acetone is 32.0kJ/mol. The normal boiling point of acetone is 56.5 degrees Celcius. What is the vapor pressure of acetone at 25 degrees Celcius?

 

Ok I think I need to use the Clausius-Clapeyron equation:

but then I only have 4 out of the 6 unknowns, delta H, T2, T1 and R. If this is the correct method, then how do I find P1?

[Fuzzwood]

What pressure does tne normal boiling point suggest?

[Zingerburger7]

Thanks! I got it now.