Environmental Engineering Reference
In-Depth Information
3.12 3 For naphthalene the following vapor pressure data were obtained from the
literature (Sato et al., 1986; Schwarzenbach et al., 1993).
T (K)
Vapor Pressure (Pa)
298.5
10.7
301.5
14.9
304.5
19.2
307.3
25.9
314.8
52.8
318.5
71.1
322.1
97.5
322.6
101
325.0
124
330.9
200
358.0
1275
393.0
5078
423.0
12756
(a) Plot the log of vapor pressure as a function of 1/ T and explain the
behavior.
(b) Estimate from the data the heat of sublimation of naphthalene and the
heat of melting (fusion) of solid naphthalene to sub-cooled liquid.
(c) Estimate the vapor pressure of naphthalene over the temperature
range given using the equations from the text and compare with the
actual values.
3.13 2 The enthalpy of vaporization of chloroform at its boiling point 313.5 K is
28.2 kJ/mol at 25.3 kPa (atmospheric pressure).
(a) Estimate the rate of change of vapor pressure with temperature at the
boiling point.
(b) Determine the boiling point of chloroform at a pressure of 10 kPa.
(c) What will be its vapor pressure at 316 K?
3.14 3 (a) The normal boiling point of benzene is 353.1 K. Estimate the boiling
point of benzene in a vacuum still at 2.6 kPa pressure. Use Trouton's
rule.
(b) The vapor pressure of solid benzene is 0.3 kPa at 243 K and 3.2 kPa
at 273 K. The vapor pressure of liquid benzene is 6.2 kPa at 283 K
and 15.8 kPa at 303 K. Estimate the heat of fusion of benzene.
3.15 3 0.5 m 3 of nitrogen at 400 kPa and 27 C is contained in a vessel kept insu-
lated from the atmosphere. A heater within the device is turned on and
allowed to pass a current of 2A for 5 min from a 120V source. Thus, elec-
trical work is done to heat the nitrogen gas. Find the final temperature for
nitrogen in the tank. C P for nitrogen gas is 1.039 kJ kg/K.
3.16 2 What pressure is required to boil water at 393 K? The enthalpy of
vaporization of water is 40.6 kJ/mol.
3.17 3 During the flooding of a residential area of New Orleans by Hurricane Kat-
rina on August 29, 2005, well-mixed floodwaters containing suspended
Lake Pontchartrain sediments entered the homes and businesses of New
Orleans.After the floodwaters stagnated, sediment settled out of the water
column and was deposited on floors and other interiors of the homes,
 
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