1. The problem statement, all variables and given/known data Given the following data, determine the heat of vaporization and normal boiling point of ammonia Temp (K): 200 210 220 230 235 Pressure (respectively)(torr): 65.3 134.3 255.7 456.0 597.0 2. Relevant equations ln(p2/p1)=-deltaH/R(1/t2-1/t1) 3. The attempt at a solution I have calculated using the first two sets of data that deltaH should be 25.179kJ/mol. The books answer within 1kJ/mol, so I'm assuming that they just used different data to come up with it. Anyways, I'm having a problem on the second part of the question where it asks to come up with a normal boiling point. The normal boiling point is when the vapor pressure equals the external pressure, right? But I have no variable in this equation that will give me the normal boiling point. Do I use this equation for both portions to the question? I'm confused. I should be able to solve the problem, just need a little boost please.