Questions and Answers of Introduction To Chemical Engineering Thermodynamics

Solve problem 14.13, except use the specified model.(a) The MAB model.(b) The SSCED model.(c) The UNIFAC model.Data from Problem 14.13:Consider the system water(1) + methylethylketone(MEK)(2) +
Solve problem 14.15, except use the specified model.(a) The MAB model.(b) The SSCED model.(c) The UNIFAC model.Data from problem 14.15:Calculate the LLE in the system 1-butanol(1) + water(2) +
Consider the system water(1) + methylethylketone(MEK)(2) + propanoic acid(PA)(3). Use UNIFAC to predict the compositions for the coexisting phases at x3α= 0.01, 0.05, and 0.10 at 298.15 K. Let α
Derive the formulas for the spinodal curves of the Flory-Huggins model and plot the spinodals (T versus xα, xβ) of several polystyrenes in cyclohexane using UNIFAC parameters to estimate the volume
In the treatment of solid-liquid equilibria, the effects of pressure on melting points are neglected.(a) Draw a schematic of the Gibbs energy of liquid and solid phases versus pressure at constant
Generate a solid-liquid equilibrium T-x diagram for naphthalene(1) + biphenyl(2) assuming ideal solutions. What are the predicted eutectic temperature and composition? The experimental eutectic point
At 25°C, the solubility of naphthalene in n-hexane is 11.9 mol%. The liquid phase is nonideal. Use the simple solution model GE /RT = Ax1x2 to predict the solubility at 10°C. (The experimental
Phenanthrene and anthracene are structurally very similar. Would you expect them to have similar solubilities in benzene at 25°C? Provide a quantitative answer, and an explanation.
Predict the solubility (in mole fraction) of phenol at the cited conditions using the specified model. (i) Use the MAB model. (ii) Use the SSCED model. (iii) Use the UNIFAC model.(a) Solubility in
A 50 wt% (22.5 mol%) solution of ethylene glycol + water freezes at about 240 K.(a) What freezing temperature would be predicted by assuming that ethylene glycol and water form an ideal solution? The
Determine the ideal solubility of naphthalene in any solvent at 40°C. Then predict the solubility and compare with the experimental solubility (shown in parentheses) for the specified solvent and
Determine the ideal solubility of anthracene in any solvent at 20°C. Then predict the solubility and compare with the experimental solubility (shown in parentheses) for the specified solvent and
Determine the ideal solubility of phenanthrene in any solvent at 20°C. Then predict the solubility and compare with the experimental solubility (shown in parentheses) for the specified solvent and
Determine the solubility curve for naphthalene in the specified solvent, and compare with the literature data:(a) Acetic acid9(b) n-hexane9(c) Cyclohexanol10(d) Acetone9(e) Chloroform11(f)
The gas condensate from a new gas well in Prudhoe Bay, Alaska has the following weight% of C5, C10, C15, C20, C25, C30, C35, C40, C45, C50, and >C50, respectively: 1, 4, 7, 10, 12, 12, 12, 12, 8, 8,
Generate an SLE phase diagram for phenol(1) + cyclohexane(2).(a) Assume an ideal solution.(b) Use MAB to model liquid phase nonidealities.(c) Use SSCED to model liquid phase nonidealities.(d) Use
Create a flow sheet analog to VLE or LLE calculations to find the melting temperature and liquid phase composition for a given solid mixture composition for the following.(a) Ideal solutions of solid
Create a flow sheet analog to VLE or LLE calculations to find the freezing temperature and solid composition for a given liquid composition when the liquids and solids form a nonideal solution.
Salicylic acid is similar in structure to aspirin. Shalmashi et al. have measured the data in Table 14.5.(a) Find the value of α for salicylic acid in water that best correlates the data, assuming
Create a flowsheet analog to VLE or LLE flash calculations to find the coexisting liquid and solid compositions that exist for a liquid-solid mixture of specified overall composition that is between
Sometimes we would like to enhance the solubility of a drug by adding a cosolvent, instead of adding antisolvent to precipitate. Making optimal use of the data in the previous problem, estimate the
Yalkowsky and Rubino (1985)14 have observed roughly linear behavior for logarithmic solubility in mixed solvents when plotted as volume fraction of the solvent/cosolvent. That is, log(xi) =
Using Fig. 15.5, without performing additional calculations, sketch the P-x-y diagram at 400 K showing the two-phase region. Make the sketch semi-quantitative to show the values where the phase
Repeat all the practice problems from Chapter 10, this time applying the Peng-Robinson equation.Practice problems from Chapter 101. The stream from a gas well consists of 90 mol% methane, 5 mol%
Acrolein (C3H4O) + water exhibits an atmospheric (1 bar) azeotrope at 97.4 wt% acrolein and 52.4°C. For acrolein: Tc = 506 K; Pc =51.6 bar; and ω = 0.330; MW =56.(a) Determine the value of
Consider two gases that follow the virial equation. Show that an ideal mixture of the two gases follows the relation B = y1B11 + y2B22.
Laugier and Richon (J. Chem. Eng. Data, 40:153, 1995) report the following data for the H2S + benzene system at 323 K and 2.010 MPa: x1 = 0.626; y1 = 0.986.(a) Quickly estimate the vapor-liquid
Consider phase equilibria modeled withWhen might ϕi be replaced by ϕi for each phase? When might ϕi = 1 be used for each phase? Discuss the appropriateness of using the virial equation for
The system ethyl acetate + methanol forms an azeotrope at 27.8 mol% EA and 62.1°C. For ethyl acetate, Tc = 523.2 K; Pc = 38.3 bar; and ω = 0.362.(a) What is the estimate of the bubble-point
Calculate the molar volume of a binary mixture containing 30 mol% nitrogen(1) and 70 mol% n-butane(2) at 188°C and 6.9 MPa by the following methods.(a) Assume the mixture to be an ideal gas.(b)
(a) Assuming zero for the binary interaction parameter (kij = 0) of the Peng Robinson equation, predict whether an azeotrope should be expected in the system CO2 + ethylene at 222 K. Estimate the
Use the virial equation to consider a mixture of propane and n-butane at 515 K at pressures between 0.1 and 4.5 MPa. Verify that the virial coefficient method is valid by using Eqn. 7.10.(a) Prepare
For the same mixture and experimental conditions as problem 15.4, calculate the fugacity of each component in the mixture, f(^)i. Use methods (a) - (e).Data from problem 15.4:Calculate the molar
(a) Assuming zero for the binary interaction parameter (kij = 0) of the Peng-Robinson equation, estimate the bubble pressure and vapor composition of the pentane + acetone system at xp = 0.728,
A vapor mixture of CO2 (1) and i-butane (2) exists at 120°C and 2.5 MPa. Calculate the fugacity of CO2 in this mixture across the composition range using(a) The virial equation for mixtures (b) The
Calculate the dew-point pressure and corresponding liquid composition of a mixture of 30 mol% carbon dioxide, 30% methane, 20% propane, and 20% ethane at 298 K using(a) The shortcut K-ratios(b) The
The equation of state below has been suggested for a new equation of state. Derive the expression for the fugacity coefficient of a component. Z=1+4cbp/(1-bp) b = Exibi where C = i Cij = √√√cii
The virial equation Z = 1 + BP/RT may be used to calculate fugacities of components in mixtures. Suppose B = y1B11 + y2B22. (This simple form makes calculations easier. Eqn. 15.1 gives the correct
The Lewis-Randall rule is usually valid for components of high concentration in gas mixtures. Consider a mixture of 90% ethane and 10% propane at 125°C and 170 bar. Estimate f(^)i for ethane.
One of the easiest ways to begin to explore fugacities in nonideal solutions is to model solubilities of crystalline solids dissolved in high pressure gases. In this case, the crystalline solids
A vessel initially containing propane at 30°C is connected to a nitrogen cylinder, and the pressure is isothermally increased to 2.07 MPa. What is the mole fraction of propane in the vapor phase?
Repeat problem 15.11, except consider naphthalene dissolved in carbon dioxide, using kij = 0.109. The molar volume of crystalline naphthalene is 123 cm3/mol.Data from problem 15.11:One of the easiest
A mixture containing 5 mol% ethane, 57 mol% propane, and 38 mol% n-butane is to be processed in a natural gas plant. Estimate the bubble-point pressure, the liquid composition, and K-ratios of the
Vapor-liquid equilibria are usually expressed in terms of K factors in petroleum technology. Use the Peng-Robinson equation to estimate the values for methane and benzene in the benzene + methane
A storage tank is known to contain the following mixture at 45°C and 15 bar on a mole basis: 31% ethane, 34% propane, 21% n-butane, 14% i-butane. What is the composition of the coexisting vapor and
The CRC Handbook lists the atmospheric pressure azeotrope for ethanol + methylethylketone at 74.8°C and 34 wt% ethanol. Estimate the value of the Peng-Robinson k12 for this system.
The CRC Handbook lists the atmospheric pressure azeotrope for methanol + toluene at 63.7°C and 72 wt% methanol. Estimate the value of the Peng-Robinson k12 for this system.
Use the Peng-Robinson equation for the ethane/heptane system.(a) Calculate the P-x-y diagram at 283 K and 373 K. Use k12 = 0. Plot the results.(b) Based on a comparison of your diagrams with what
One mol of n-butane and one mol of n-pentane are charged into a container. The container is heated to 90°C where the pressure reads 7 bar. Determine the quantities and compositions of the phases in
Consider a mixture of 50 mol% n-pentane and 50 mol% n-butane at 15 bar.(a) What is the dew temperature? What is the composition of the first drop of liquid?(b) At what temperature is the vapor
LPG gas is a fuel source used in areas without natural gas lines. Assume that LPG may be modeled as a mixture of propane and n-butane. Since the pressure of the LPG tank varies with temperature,
The synthesis of methylamine, dimethylamine, and trimethylamine from methanol and ammonia results in a separation train involving excess ammonia and converted amines. Use the Peng-Robinson equation
The kij for the pentane + acetone system has been fitted to a single point in problem P15.6. Generate a P-x-y diagram at 312.75 K.Data from problem P15.6A vapor mixture of CO2 (1) and i-butane (2)
For the gas/solvent systems below, we refer to the “gas” as the low molecular weight component. Experimental solubilities of light gases in liquid hydrocarbons are tabulated below. The partial
Estimate the solubility of carbon dioxide in toluene at 25°C and 1 bar of CO2 partial pressure using the Peng-Robinson equation with a zero binary interaction parameter. The techniques of problem
Oxygen dissolved in liquid solvents may present problems during use of the solvents.(a) Using the Peng-Robinson equation and the techniques introduced in problem 15.27, estimate the solubility of
Estimate the solubility of ethylene in n-octane at 1 bar partial pressure of ethylene and 25°C. The techniques of problem 15.27 may be helpful. Does the system follow Henry’s law up to an ethylene
A gas mixture follows the equation of statewhere b is the size parameter,and a is the energetic parameter,Derive the formula for the partial molar enthalpy for component 1 in a binary mixture, where
Henry’s law asserts that f^i = hixi, when xi is near zero, and hi is the Henry’s law constant. Gases at high reduced temperatures can exhibit peculiar trends in their Henry’s law constants. Use
The procedure for calculation of the residual enthalpy for a pure gas is shown in Example 8.5. Now consider the residual enthalpy for a binary gas mixture. For this calculation, it is necessary to
The vapor-liquid equilibria for the system acetic acid(1) + acetone(2) needs to be characterized in order to simulate an acetic anhydride production process. Experimental data for this system at 760
A gaseous mixture of 30 mol% CO2 and 70 mol% CH4 enters a valve at 70 bar and 40°C and exits at 5.3 bar. Does any CO2 condense? Assume that the mixture follows the virial equation. Assume that any
A mixture of methane and ethylene exists as a single gas phase in a spherical tank (10 m3) on the grounds of a refinery. The mixture is at 298 K and 1 MPa. It is a spring day, and the atmospheric
(a) At 298 K, butane follows the equation of state: P(V - b) = RT at moderate pressures, where b is a function of temperature. Calculate the fugacity for butane at a temperature of 298 K and a
The Soave equation of state is:where the mixing and combining rules are given by Eqns. 15.8 and 15.9. Develop an expression for the fugacity coefficient and compare it to the expression given by
The following equation of state has been proposed for hard-sphere mixtures:whereDerive an expression for the fugacity coefficient. 2 RT (1-7p)
The equation of state below has been suggested. Derive the expression for the fugacity coefficient. Z=1 + 4cp/(1-bp) where b = C = ΣΣΕ Cij = constant
The following free energy model has been suggested as part of a new equation of state for mixtures. Derive the expression for the fugacity coefficient of component 1. A(T, V) - Aig(I, V) RT where B
Consider the methanol(1) + water(2) + acetone(3) system with a feed shown in Figure 16.10(a). Rate each of the following products as impossible or possible, and explain. (a) (b) (c) (d) D(X1,
As the research scientist of a company where phase equilibria is under study, you are approached by a laboratory technician with the most recent (and incomplete) high pressure phase equilibria
A binary mixture obeys a simple one-term equation for excess Gibbs energy, GE = Ax1x2, where A is a function of temperature: A = 2930 + 5.02E5/T(K) J/mol.(a) Does this system exhibit partial
Using the value kij = 0.084 fitted to the system methanol(1) + benzene(2), use the Peng- Robinson equation to plot P-x-y behavior of the system at the following temperatures: 350 K, 500 K, 520 K.
Use UNIFAC to model the methanol(1) + methylcyclohexane(2) system. Provide a P-x-y diagram at 60°C and 90°C, and a T-x-y at 0.1013 MPa.
Use UNIFAC to model the methanol(1) + hexane(2) system. Provide a P-x-y diagram at 50°C and 25°C, and a T-x-y at 0.1013 MPa.
Model the system CO2(1) + tetralin(2) using kij = 0.10. Generate a P-x-y diagram at 20°C, 45°C, and a T-x-y at 12 MPa and 22 MPa. What type of phase behavior does the system exhibit?
(a) Rank the following molecules in order of increasing oxidation of carbon and give the oxidation state of C for each: CO2, -COH(aldehyde), -COOH(carboxylic acid), -CO- (ketone), -COH(alcohol),
For the systems specified below, obtain residue curve maps and plot the range of possible distillate and bottoms compositions for the given feeds. UNIQUAC parameters are provided.(a) methanol(1) +
An equimolar mixture of H2 and CO is obtained by the reaction of steam with coal. The product mixture is known as “water-gas.” To enhance the H2 content, steam is mixed with water-gas and passed
Consider an equimolar mixture of methanol(1) + water(2) + acetone(3). Demonstrate that it is not possible to obtain pure acetone as distillate from a single-feed column by generating a residue curve
For their homework assignment three students, Julie, John, and Jacob, were working on the formation of ammonia. The feed is a stoichiometric ratio of nitrogen and hydrogen at a particular T and
One method for the production of hydrogen cyanide is by the gas-phase nitrogenation of acetylene according to the reaction: N2 + C2H2 ⇆ 2HCN. The feed to a reactor in which the above reaction
Butadiene can be prepared by the gas-phase catalytic dehydrogenation of 1-butene: C4H8 ⇆ C4H6 + H2. In order to suppress side reactions, the butene is diluted with steam before it passes into the
The simple statement of the Le Châtelier principle leads one to expect that if the concentration of a reactant were increased, the reaction would proceed so as to consume the added reactant.
The production of NO by the direct oxidation of nitrogen occurs naturally in internal combustion engines. This reaction is also used to produce nitric oxide commercially in electric arcs in the
The following reaction reaches equilibrium at the specified conditions.The system initially contains 3 mol H2 for each mole of styrene. Assume ideal gases. For styrene, ΔG°f,298 = 213.18 kJ/mol,
Ethylene oxide is an important organic intermediate in the chemical industry. The standard Gibbs energy change at 298 K for the reaction C2H4 + ½O2 ⇆ C2H4O is -79.79 kJ/ mole. This large negative
For the cracking reaction,the equilibrium conversion is negligible at room temperature but becomes appreciable at temperatures above 500 K. For a pressure of 1 bar, neglecting any side reactions,
The water-gas shift reaction is to be carried out at a specified temperature and pressure employing a feed containing only carbon monoxide and steam. Show that the maximum equilibrium mole fraction
Assuming ideal gas behavior, estimate the equilibrium composition at 400 K and 1 bar of a reactive gaseous mixture containing the three isomers of pentane. Standard formation data at 400 K are
One method for the manufacture of synthesis gas depends on the vapor phase catalytic reaction of methane with steam according to the equation CH4 + H2O ⇆ CO + H2. The only other reaction which
Ethanol can be manufactured by the vapor phase hydration of ethylene according to the reaction: C2H4 + H2O = C2H5OH. The feed to a reactor in which the above reaction takes place is a gas mixture
Ethylene is a valuable feedstock for many chemical processes. In future years, when petroleum is not as readily available, ethylene may be produced by dehydration of ethanol. Ethanol may be readily
Is there any danger that solid carbon will form at 550°C and 1 bar by the reaction 2CO = Cs + CO2?
Calculate the equilibrium percent conversion of ethylene oxide to ethylene glycol at 298 K and 1 bar if the initial molar ratio of ethylene oxide to water is 3.0.To simplify the calculations, assume
The catalyzed methanol synthesis reaction, CO(g) + 2H2(g) = CH3OH(g), is to be conducted by introducing equimolar feed at 200°C. What are the mole fractions and the temperature at the outlet if the
A gas stream composed of 15 mol% SO2, 20 mol% O2, and 65 mol% N2 enters a catalytic reactor operating and forms SO3 at 480°C and 2 bar.(a) Determine the equilibrium conversion of SO2.(b) Determine
Acetic acid vapor dimerizes according to 2A1 ⇆ A2. Assume that no higher-order associations occur. Supposing that a value for Ka is available, and that the monomers and dimers behave as an ideal
(a) As part of a methanol synthesis process similar to problem 17.10, one side reaction that can have an especially unfavorable impact on the catalyst is coke formation. As a first approximation of
Acrylic acid is produced from propylene by the following gas phase reaction:A significant side reaction is the formation of acetic acid:The reactions are carried out at 310°C and 4 bar pressure
The 10/25/93 issue of Chemical and Engineering News suggests that the thermodynamic equilibrium in the isomerization of n-butene (CH3CH = CHCH3, a mix of cis and trans isomers) is reached at a

Showing 100 - 200 of 906