Map If you were going to graphically determine the enthalpy of The vapor pressur
ID: 477473 • Letter: M
Question
Map If you were going to graphically determine the enthalpy of The vapor pressure, P, of a certain liquid was measured at two temperatures, T. vaporizaton, vap for this liquid, what points would you plot? The data is shown in this table. Number Number T (K) P (kPa) To avoid rounding point 1: 325 3.41 errors, use three significant figures in 575 5.50 the X values and four Number Number significant figures in NOTE: Keep the pressure units in kPa the y values. point 2 Determine the rise, run, and slope of the line formed by these points. slope rise run Number Number Number What is the enthalpy of vaporization of this liquid? Number J mol AH vapExplanation / Answer
Let T(K) be x and P(kPa) your y
Point 1: x1= 1/325= .00307, y1=ln(3.41)= 1.22
Point 2: x2= 1/575= .00173, y2=ln(5.50)= 1.70
Rise= y2-y1= 1.70-1.22= 0.48
Run= x2-x1= .00173-.00307= -.00134
Slope= y2-y1/x2-x1= .48/-.00134= -358.208
deltaHvap= mxR= 358.208x8.314= 2978.14 J/mol
(R is a constant)