Chemical Forums
Chemistry Forums for Students => Physical Chemistry Forum => Topic started by: Jack_56 on April 28, 2021, 09:08:55 AM

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 ClausiusClapeyron 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. :)

Is boiling point an intensive, or extensive property?

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!!