Good morning (or afternoon depending on where you are). We did an experiment a couple days ago that involved heating ethanol to determine its heat of vaporization. We collected data for both temperature (in Celsius) as well as pressure (in kPa). We monitored between 85 degrees C to 35 degrees C. We ended up with a couple values that I'm having a hard time stringing together. From the CRC, I know that the Heat of Vaporization for Ethanol is:
38.56 kJ/mol @ 78.3 degrees C
42.32 kJ/mol @ 25.0 degrees C
As for our data from our first trial, we go:
m (slope) : -4044
b (y-intercept) : 16.13
Correlation : -0.9986
RMSE : 0.02940
I realize that Correlation and RMSE are both values for accuracy that just simply need to be reported. However, I'm having a hard time fitting m (slope) and b (y-intercept) into the Clausius-Clapeyron equation:
ln P = - (:delta:Hvap/RT) + C
I don't know which values convert to which. It looks like "C" in the Clausius-Clapeyron equation is related to b, the y-intercept. I'd also imagine that R is the gas constant, 8.314 J mol−1K−1. What I'm not sure is where I'm supposed to fit in the slope. I am also guessing that since our data was originally collected in C, we'll need to convert to K since we're using the gas constant, but I don't know which data to convert to K. Argh.
Anyways, from this data, I need to know how to report relationships between vapor pressure and temp, the significance of the slope, and I'm also supposed to be able to calculate the heat of vaporization for ethanol and the boiling point.
Could anyone lend some pointers?