By using the Clausius-Clapeyron equation,lnP=Hvap/RT +C , derive the relationship between the vapor pressures,P1 and P2, and the absolute temperatures at which they were measured,T1 and T2 .
2 answers
http://www.science.uwaterloo.ca/~cchieh/cact/c123/clausius.html
ln(P1/P2)={-ÄHvap[(1/T1)-(1/T2)]}/R