PDA

View Full Version : Caculating normal boiling point using an equation of a line


ahhppull
Feb15-11, 05:04 PM
1. The problem statement, all variables and given/known data

The equation for the best fit line was y = - 5307.5x + 19.55. Using the equation of the best fit line, calculate the heat of vaporization and the normal boiling point (in C) of this volatile liquid. (Hint: What is the value of Pvap when liquid boils at its normal boiling point?

2. Relevant equations

Heat of vaporization = -(slope x R) R= 8.314 j/mol*k

3. The attempt at a solution


The heat of vaporization is 44.127 kJ/mol, but I'm unsure of how to calculate the boiling point.

I tried using the Clausius-Clapeyron equation to find the boiling point. I got 99 C, but I'm unsure if its right. If it helps, the next problem following this problem lists several compounds and I have to find out what compound it is using the Normal Boiling point and heat of vaporization

Ethanol 78.3 C 42.4kJ/mol
iso-Propanol 82.3 C 45.4 kJ/mol
Cyclohexane 80.7 C 33.1 kJ/mol

I know that its not cyclohexane because its heat of vaporization differs from mines.

ahhppull
Feb15-11, 06:28 PM
Actually, the clausius equation doesn't work because I forgot to convert kJ to joules while doing the equation.