Henrys Law and Raoults Law Questions

Problem Set #6 

When possible, use the values for constants from our text. If you get them from other sources (if they are not in the book) cite where you got them from.

  1. (10 pts) The vapor pressure of Hg @ 20.00 °C is 1.201 millitorr. Calculate the vapor pressure of Hg dispersed as 65 nm droplets at this temperature. You may assume the density of Hg is 13.546 g/cm3. Surface tension in notes.
  2. (20 pts) For the following solutions of components A and B, the following pressures were found. Xs are mol fractions in liquid, Ys are mol fractions in vapor.

X(A)

Y(A)

P (torr)

0.0000

0.0490 0.3120

0.4750 0.6535

0.7905

1.0000

0.0000

0.0175 0.1090

0.1710 0.2550

0.3565

1.0000

255.6

257.9

211.3

184.4

156.0

125.7

55.03

Make 2 plots and use different colors for A and B. As a function of X(A), plot

  1. the Raoult’s law predictions (dashed lines), the P(A), P(B) and P curves, and the activities a(A) and a(B) based on Raoult’s law as the reference state.
  2. the activity coefficients, g(A) and g(B) based on Raoult’s law as the reference state.

3. (10 pts) for the following data for the partial pressure of Br2 dissolved in CCl4, plot the data to determine the Henry’s law constant. Would you consider this an “ideal” system?

X(Br2)

P (torr)

0

0.00394

0.00420 0.00599 0.0120

0.01300

0.02360

0.02380

0.02500

0

1.52

1.60 2.39

4.27 5.43

9.57

9.83

10.27

I didn’t ask for it here, but be sure you can calculate the activities and activity coefficients for H.L.

 

Order a unique copy of this paper
(550 words)

Approximate price: $22