The vapor pressure of the liquid HF is measured at different temperatures. The following vapor pressure data are obtained.

Question

Temperature(K) Pressure mmHg
250 129.63
260 206.65
270 318.22
280 475.16

Determine the enthalpy of vaporization.

I have know idea how to start this. Thank you for your help.

Answer 1

You are supposed to plot ln p vs 1/T. You will get a straight line with a negative slope. The slope = dHvap/R.

Answer 2

Ok when I did the graph I got -2.99e3 as the slope. Is this the answer or do I have to do something else now?

Answer 3

Nevermind I actually figured it out. Thank you.

Answer 4

well i would really help u hannah if i knew how to do it