材料热力学补充习题forstudents.doc

1、At 300K, 1 mole ideal gas expands from p =10pQ to p= pQ isothermally and reversibly calculate (1) Calculate the q, w, DHm, DUm, DGm, DFm and DSm; (2) If the gas expands isothermally to a vacuum until the pressure reaches p= pQ, calculate q, w, DHm, DUm, DGm, DFm and DSm. 2. Calculate the equilibrium vapour pressure (atm) of sodium for an aluminum melt containing 0.005 mol% sodium(Na). The activity coefficient of sodium in aluminum is 320 and the vapor pressure of pure sodium at 750 C is 0.23 atm.3、At 413.15K，the vapor pressure of pure C6H5Cl and C6H5Br are 125.238kPa and 66.104kPa. Given that the two pure liquids are mixed and form ideal solution. If a solution formed by the two pure liquids boils at 413.15K、101.325kPa, please calculate the composition of the solution and the vapor above it. IIIIII4、Given that when a specie A in a binary solution, its vapor pressure varies with its concentration in the pattern illustrated below. Make a table to indicate the activity, activity coefficient and chemical potential of A in different concentration sections I 、II and III，using its pure substance as standard state. 5、At 300K, the vapor pressure of liquid A and liquid B are 37.33kPa and 22.66kPa. When 2 moles of A and 2 moles of B are mixed to form a solution, the vapor pressure above the solution is 50.66kPa, and the molar fraction of A in the vapor is 0.60. Given that vapors can be taken as ideal gases. Calculate aA( R )and aB( R) in the solution, gA and gB, DmixG, If the solution is an ideal solution, what is the value of DmixGid? What is the value of DmixGex of this solution? 6、The variation, with composition, of GE for Fe-Mn alloys at 1863K is listed below: XMn0.10.20.30.40.50.60.70.80.9GmE, Joules395703925105411001054925703395a、Is the process to form Fe-Mn alloy at 1863K an exothermic one or an endothermic one ?b. Does the system exhibit regular solution behavior?c. Calculate and at XMn = 0.6;d. Calculate at XMn = 0.4;e. Calculate the partial pressures of Mn and Fe exerted by the alloy of XMn= 0.27、Melts in the system Pb-Sn exhibit regular solution behavior. At 473C, aPb = 0.055 in a liquid solution of XPb = 0.1. Calculate the value of for the system and calculate the activity of Sn in the liquid solution of XSn = 0.5 at 500C. 8、With respect to the Ellingham diagram, answer the following questions: a) Explain the slope changes for the reaction 2Mg + O2 = 2MgO;b) You want to heat up and a piece of silicon metal to 1600C, decide on a suitable crucible material;c) What is the value of DHQ of formation of TiO2 ?d) Find DGQfor the reaction Fe + 0.5O2 =FeO at 1200 C;e) Find DGQ for the reaction 3Mg + AlO3 = 3MgO + 2A1 at 1500 C;f) What is the equilibrium oxygen pressure when metallic titanium is in equilibrium with TiO2 at 1000 C?g) If you want to reduce pure TiO2 to pure metallic titanium at 1000C using a CO/CO2 gas mixture, what is the minimum CO/CO2 ratio that can achieve such a reduction. 9、Answer the following questions according to Ellingham diagram: At what temperature(s) C can reduce SnO2(s)、Cr2O3(s) and SiO2(s) ？ At what temperature, the decomposition pressure of CuO reaches 1.01325105 Pa ? The temperature(s) at which Fe3O4 can be reduced to FeO by H2 ? DGQ when Mg reduces Al2O3 at 1000C, At what temperature, for the reaction , ? Calculate the DG when Fe reacts with O2 at 105Pa and 1010Pa respectively at1000C, and as well. Calculate the equilibrium constant of reaction at 1100C () At what temperature, for reaction, the is 104/1 ? 10、The standard Gibbs free energy change for reaction I: Ni（s） + 1/2 O2 = NiO（s）is -244560 + 98.53TlnT J/ mol , question:a) How much is the standard Gibbs free energy change for reaction II : 2Ni（s） + O2 = 2 NiO（s）b) Calculate the equilibrium constants for reaction I and reaction II respectively at 1000 C. c) At 1000 C, when oxygen pressure is maintained at 10-4 atm, how much is the Gibbs free energy change for reaction I ? Can reaction I proceed forward ? Is Ni stable under this condition ? Is NiO stable under this condition ?d) At 1000 C, how much should be the oxygen pressure if we want the Gibbs free energy change for reaction I to be 0, and how much should be the oxygen pressure if we want a Ni-NiO-O2 system to be at equilibrium ? e) At 1000 C, what is the condition to prevent Ni from being oxidized ? and what is the condition to reduce NiO ?11、Liquid FeO is reduced to metallic iron at 1600 C with CO(gas) accordingto the following reaction:FeO(liquid) + CO(g) = Fe(liquid) + CO2a) Calculate DGQ at 1600 C for this reaction b) Detennine the minimum CO/C02 ratio required to reduce pure liquid FeO to pure metallic iron at 1600 C.c) Determine the minimum CO/CO2 ratio required to reduce FeO dissolved in a liquid slag to metallic iron at 1600 C. The metallic iron formed has a purity of 96 mole % iron. The activity of FeO in the liquid slag is 0.3. CO(g) at 1600 C: DGQ= -274.9 kJ/molCO2(g) at 1600 C: DGQ = -396.3 kJ/mol FeO at 1600 C: DGQ = -144.6 kJ/molR= 8.314 J/ mol.K= 1.987 ca1/mol.K12、In an experiment, it was found that the Ar was not pure enough. So a setup was devised in an attempt to purify the Ar, as illustrated