6 of 18 Map do The vapor pressure, P, of a certain liquid was measured at two te

Question

6 of 18 Map do The vapor pressure, P, of a certain liquid was measured at two temperatures, T If you were going to graphically determine the enthalpy of vaponzaton, Hap, for this liquid, what points would you plot? The data is shown in this table. T (K) P (kPa) 225 3.36 To avoid rounding errors, use three point 1 675 6.28 significant figures in l the x values and four NOTE: Keep the pressure units in kPa. D-||D-- ]|t significant figures in the y values point 211 Determine the rise, run, and slope of the line formed by these points. rise run slope Number What is the enthalpy of vaporization of this liquid? Number J/ mol vap Previous & Give us

Explanation / Answer

we know that

the slope of the graph lnP vs 1/T can be used to obtain dHvap

so the x values will be 1/T and y values will be ln P

point 1 :

x = 1/225 = 0.00444

y = ln 3.36 = 1.212

point 2 :

x = 1/675 = 0.00148

y = ln 6.28 = 1.837

now

rise = y2 - y1 = 1.837 - 1.212 = 0.625

run = x2 - x1 = 0.00148 - 0.00444 = -0.00296

slope = rise / run = 0.625/ (-0.00296) = -211.15

now

we know that

slope = -dHvap / R = -211.15

dHvap = 211.15 x R = 211.15 x 8.314

dHvap = 1755.5 J /mol

Related Questions

Navigate

• Browse (All)
• Browse 6
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.