[Jack_56]

Good Day everyone.

You are given 26 g of Benzene and asked to calculate the pressure at which the sample will boil at 47 °C.
I understand we must use the integrated form of the Clausius-Clapeyron equation such that
ln(p/p*) = -ΔvapH/R (1/T - 1/T*)

At the normal boiling point of course the pressure will be 1 atm and we can substitute our values and solve for p.

However do we need to take into account the number of moles in the sample . For instance do we have to say ΔvapH = ΔvapH° x n (benzene) and use this in the equation ? If we do this the units don't seem to work out. Or does the equation function independent of the amount of substance given?
Any guidance with explanations will be really appreciated. Thanks all.

[Borek]

Is boiling point an intensive, or extensive property?

[Jack_56]

Oh. I see what you're saying. Boiling point is intensive so won't depend on moles. I got confused since I was thinking about boiling point elevation (which does depend on molality). Thank you!!