﻿ Problems and Solutions Chapter 2

# ## Problems and SolutionsChapter 3 Correlation and Estimation of Pure Component Properties

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03.07           Enthalpy of Reaction and Equilibrium Concentration of the Theoretically Possible n-Butane – Isobutene Isomerization Reaction in the Gas Phase (p. 74)

P03.01       Conversion of cP-Coefficients for Carbon by Parameter Regression

Regress a third order polynomial to results of the equation for the heat capacity at constant pressure for graphite reported in “Butland, A.T.D.; Maddison, R.J., The specific heat of graphite: an evaluation of measurements, J. Nucl. Mater., 1973, 49, 45-56”: P03.02        Calculation of the Enthalpy of Evaporation at a Different Temperature Using the Watson-Equation

Calculate the enthalpy of vaporization of ethanol at 25°C and 200°C using the Watson-equation. The enthalpy of vaporization at the normal boiling temperature of 351.41K is 39.183 kJ/mol. The critical temperature of ethanol can be found in Appendix A.

P03.03       Estimation of Critical Data of Hexene Using the Joback-Method

Estimate the critical data TC, PC and vC of n-hexene using the Joback-method.

P03.04       Estimation of Standard Enthalpy and Standard Gibbs Energy Using the Joback Method

Determine the enthalpy of formation as well as the Gibbs energy of formation for hexane and benzene at 25°C and 1 atm (ideal gas) using the Joback group contribution method.

P03.05         Solid and Liquid Vapor Pressure Calculations Using the Wagner-Equation (DDBSP, Excel)

Retrieve the vapor pressure data of naphthalene from the free DDBSP Explorer Edition and export the values to MS-Excel. Regress the coefficients of the Wagner equation (Eq. 3.37) to the experimental data using the Excel Solver Add-In. Use the Wagner equation to calculate the vapor pressure of the hypothetical subcooled liquid. From the vapor pressures of the hypothetical subcooled liquid and the sublimation pressure data found in the free DDBSP Explorer Edition, estimate the melting point and heat of fusion for naphthalene. Compare the results to the values given in the DDB.

(zip)
planned for June 2012
Mathcad (2001) - Solution as XPS

P03.06         Estimation of the Melting Temperature of Naphthalene Using the Joback Method

Estimate the melting temperature of naphthalene using the Joback method and compare the result to the recommended value of 353.35 K. The estimation can either be performed by hand using the group contributions in Table 3.1 or with the help of the program Artist in the free DDBSP Explorer Edition.

solution video  (large), (medium), (small)

P03.07       Retrieval and Estimation of Liquid Density Data of THF (DDBSP)

Retrieve the saturated liquid density data for tetrahydrofuran in the free DDBSP Explorer Edition and plot the data together with the prediction of the Campell/Thodos method. In Artist, estimate the liquid density at the normal boiling point and compare the results to the data and estimation above.

solution video  (large), (medium), (small)

P03.08         Regression of Trichloromethane Vapor Pressure Data Using DDBSP

In the free DDBSP Explorer Edition, regress the liquid vapor pressure data for trichloromethane using the Antoine equation. Remove outliers that are not in agreement with the majority of the authors. Check the manual to clarify the exact formulation of the Antoine-equation. Convert the parameters so that the Antoine equation employs the natural logarithm and yields the vapor pressure in the unit kPa.

solution video  (large), (medium), (small)

P03.09         Liquid Thermal Conductivity Data For Glycol and 1-Butanol from the DDB

Compare the liquid thermal conductivity data for glycol (1,2 ethanediol) and 1-butanol using the free DDBSP Explorer Edition. Interpret the difference in the absolute value and the temperature dependence on a molecular basis.

solution video  (large), (medium), (small)

P03.10         Vapor Pressure Estimation Using Clausius-Clapeyron

The boiling temperature of water at J1 = 90°C is P1s = 0.702 bar. At this temperature, the enthalpy of vaporization is 2282.5 J/g. Estimate the vapor pressure at J2 = 95°C using the Clausius-Clapeyron equation.
Collected as XPS

P03.11         Standard Enthalpy and Gibbs Energy of Formation of Ethylene Glycol Using the Joback Method

Estimate the standard enthalpy of formation and the standard Gibbs energy of formation of ethylene glycol (CH2OH-CH2OH) using the Joback method. Can a similarly good result be expected as in case of ethyl acetate (Example 3.6)?
Collected as XPS

P03.12       Heat Capacity of a Gas From Heat Duty of Heating

An ideal gas is heated up from T1 = 300 K to T2 = 350 K. The specific duty is evaluated to be q12 = 1040 J/mol. Describe the chemical nature of the gas.
Collected as XPS

P03.13       Speed of Sound in Water Vapor (Ideal Gas)

Calculate the speed of sound in water vapor at J = 100°C, P = 1 bar. The vapor can be regarded as an ideal gas.
Collected as XPS

P03.14       Enthalpy of Vaporization of R134a Using Clausius-Clapeyron

For the refrigerant R134a, the following data are given:

Ps (0°C) = 2.006 bar    rV (0°C) = 14.428 kg/m3      rL (0°C) = 1294.78 kg/m3
Ps (10°C) = 4.146 bar  rV (10°C) = 20.226 kg/m3  rL (10°C) = 1260.96  kg/m3
Estimate the enthalpy of vaporization at J = 5°C using the Clausius-Clapeyron equation and interpolate the vapor pressure at J = 5°C with the Hoffmann-Florin equation.
Collected as XPS

P03.15       Pressure Dependence of the Melting Point of Water Using Clausius-Clapeyron

At P = 1.01325 bar, the melting point of water is Jm = 0°C. How is the melting temperature affected, if the pressure rises by 20 bar? Use the Clausius-Clapeyron equation for the solid-liquid equilibrium. The following values are given:

D
hm = 333 J/g                     rL = 1000 kg/m3                 rS = 917 kg/m3
Collected as XPS

P03.16         Complete Property Estimation for R134a

Estimate the whole set of physical properties (critical temperature, pressure, volume and compressibility, acentric factor, boiling and melting temperature, heat of fusion and heat of vaporization, standard enthalpy and standard Gibbs energy of formation, vapor pressure, liquid density, ideal gas heat capacity, liquid and vapor viscosity, liquid and vapor thermal
conductivity, and surface tension(temperature-dependent properties at ϑ = 20 °C) of R134a (1,1,1,2-tetraﬂuoroethane, CH2F–CF3) without using any given information except its molar mass (102.03 g/mol) and its chemical structure. Compare the results with the values obtained with the data and equations given in Appendix A.

planned for June 2012

P03.17       Ideal Gas Heat Capacity of Methane from Spectroscopic Data

Estimate the ideal gas heat capacity of methane at T = 600 K using the following information about its basic frequencies from spectroscopic data:

Q
1 = Q2 = Q3 = 1876.6 K
Q4 = Q5 = 2186 K
Q6 = 4190 K
Q7 = Q8 = Q9 = 4343 K

The characteristic temperature Q is an abbreviation for Q = hno/k. Verify that the molecule has nine basic frequencies for the vibration.

P03.18       Small Droplet Vapor Pressure of Water and n-Hexane at the Bankroft Point

At approximately T = 380 K, the vapor pressure curves of water and n-hexane intersect. Calculate the difference in the vapor pressures, if both substances form drops with diameters of d = 2 nm.

(zip)
Mathcad (2001) - Solution as XPS

P03.19       Liquid Viscosity Estimation for 1,1,2-Trichloroethane Using Rarey/Nannoolal

Estimate the liquid dynamic viscosity of 1,1,2-trichloroethane at T = 330 K using the Rarey/Nannoolal method.

Excel Excel - Solution (zip)

P03.20         Vapor Pressure of p-Tolualdehyde Using Rarey/Moller

Estimate the vapor pressure of p-tolualdehyde at J = 150°C using the Rarey/Moller method. The normal boiling point is Jb = 206.3°C. Use the Clausius-Clapeyron equation to determine the corresponding enthalpy of vaporization.

P03.21         Isobaric Ideal Gas Heat Capacity of Ammonia From Speed of Sound

The speed of sound of ammonia at T = 303.15 K, P = 0.01 bar is w* = 439.11 m/s. Calculate the corresponding isobaric ideal gas heat capacity.

(zip)
Mathcad (2001) - Solution as XPS

P03.22         Enthalpy of Vaporization of Benzene at the Normal Boiling Point Using Clausius-Clapeyron

Estimate the enthalpy of vaporization of benzene at the normal boiling point using the vapor pressure coefficients and the critical constants from App. A. For the vapor phase, use
a)  the ideal gas law
b) the Soave-Redlich-Kwong equation of state
Compare the results with the correlation given in App. A.