精華區beta NTU-Exam 關於我們 聯絡資訊
課程性質︰必修 開課系所︰化學 2002. 1.18 Total:255% (Questions 1-6 are derived from old examination and quiz 1-7) 非選:155% 1.Name the following compounds: (2%*10=20%) a.NaClO, b.NaClO4, c.Cr2O7 2-, d.KHCO3, e.H2SO3, f.GaN, g.CdSe, h.InAs, i.量筒, j.拋棄式滴管 2.a.Balance the following oxidation-reduction reactions, which occurs in acidic solution, using the half-reaction method CH3OH(aq) + Cr2O7 2-(aq) → CH2O(aq) + Cr3+(aq) (5%) b.Similar to the above statement except that the reaction takes place in basic solution MnO4 -(aq) + S2-(aq) → MnS(s) + S(s) (5%) 3.For the van-der Waals equation of the real gas Pobs= = nRT/(V-nb) - a((n/V)^2) a.Please define van-der Waals constants a and b (5%) b.For the following gases, which has the smallest value of b, and write down the order of a from the smallest value. (5%) He,Ar,CH4,NH3 c.At higher pressure such as >1000atm pressure calculated from the can-der Waals equation shows significant deviation from the observed one. Give a reasonable explanation. (5%) 4.From the relationship between ΔG0 and equilibrium constant Keq, prove the van't Hoff equation, i.e. lnKeq is linearly proportional to 1/T. (5%) 5.If platinum metal will dissolve in 王水 but not in either concentrated nitric or concentrated hydrochloric acid individually. a.Write down the reduction half reaction for Pt+2, PtCl4 2- and NO3 - ( forming NO in the acidic solution) and assign each reaction with correct ε0 from the following valued:ε0=0.96,0.755 and 1.188V. (5%) b.The composition of 王水(2%), and its common name in English(3%) 6.a.How many degrees of freedom in motion does CO2 have? in which how many can be ascribed to the translational, rotational and vibration motions, respectively? (5%) b.According to the theory of Boltzman population moleculed have a greater tendency to populate at (a)highly electronic state (b)highly vibrational state (c)highly rotational state at room temperature. Give the order(of tendency) and explanation. (5%) 7.Explain the following definition and questions: a.The first, second and third law of thermodynamics (5%) b.Open system, closed system, isolated system (5%) c.Could you describe an experimental method to measure the Maxwell distribution of gas velocity? (5%) d."Green House" effect (5%) e.What does state function mean? Which of the following properties are state functions:potential energy, work, entropy, enthalpy, heat and free energy? (5%) f.Give the definition of exothermic, endothermic, endergonic and exergonic reactions. (5%) g.Which one has the largest Cv value among the gas molecules H2, N2, CO, SO2 . Ar at room temperature? Explain. (5%) h.(a)Which one is more stable, graphite of diamond? Give explanation from the thermodynamic viewpoint (i.e.entropy and enthalpy)? (5%) (b)If graphite is more stable, why didn't you see the conversion of diamond into graphite within your lifetime? (5%) 8.Calculate the change in entropy occurs when a sample containing 2.00mole of water is heated from 50度C to 150度C at 1atm pressure. The molar heat capacity for H2O(l) and H2O(g) are 73.5JK-1mol-1 and 36.4JK-1, respectively , and the enthalpy of vaporization for water is 40.7KJ/mol at 100度C (10%) 9.The value of Keq is 3.7×10^-6 at 900K for ammonia synthesis reaction. Assuming the value of ΔH0 for this reaction is -92KJ, calculated the value of Keq at 550K. (10%) 10.1.00mol of perfect gas at 27度C is expanded isothermally from an initial pressure of 3.00atm to a final pressure of 1.0atm in two ways:(1)reversibly and (2)against constant external pressure of 1.0atm. Calculate q, w, ΔH, ΔSsys, ΔSsurr and ΔSuniv (20%) -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.112.242.61 > -------------------------------------------------------------------------- < 作者: abacada (力量的極限) 看板: NTU-Exam 標題: [試題] 90年上 周必泰 普通化學甲上期末考partB 時間: 01/26/2005 01:26:27 Wed Multiple Choices (5%*20=100%) 1.The standard molar entropies of vaporization of liquids will be on the order of (a)benzene>water>methane,(b)water>benzene>methane,(c)water>methane> benzene,(d)methane>water>benzene,(e)benzene>methane>water 2.Which of the following are intensive properties (a)weight,(b)volume,(c)force,(d)pressure,(e)density,(f)work,(g)heat,(h)heat capacity 3.For a spontaneous reaction, which of the following statements are correct: (a)The entropy change of the system must be >0,(b)The entropy change of the surrounding must be >0,(c)The total entropy change must be <0,(d)the entropy change in the isolated system must be >0,(e)the change of the system free energy must be >0 4.Calculate the change in entropy when 50g of water at 80度C is poured into 100g of water at 10度C in an insulated vessel given that Cp,m=75.5JK-1mol-1 (a)2.8J/K,(b)-3.2J/K,(c)10.3J/K,(d)3.2J/K,(e)23J/K,(f)-12J/K 5.At 0K, the CO2 moleulfe only has two orientations. The entropy of 1 mole CO2 is then calculated to be (a)2.98J/K,(b)5.76J/K,(c)3.65J/K,(d)6.67J/K,(e)12.4J/K 6.Which of the following relations are correct (a)H=G-TS,(b)G=H-TS,(c)for a irreversible change dSsurr>dq/T,(d)for a reversible change dSsys=dq/T,(e)for an irreversible change ΔSsys+ΔSsurr>0, (f)at the phase transition ΔSsys=ΔH/T 7.The compression factor Z at 1atm is on the order of (a)CH4>H2>C2H4>NH3,(b)H2>CH4>C2H4>NH3,(c)NH3>CH4>C2H4>H2,(d)C2H4>CH4>H2>NH3, (e)CH4>C2H4>NH3>H2 8.Which of the following statements are correct (a)the root mean square speed of a perfect gas=√(3RT/M),(b)the mean speed of a gas=√(RT/M),(c)the root mean square speed of a perfect gas=√(8RT/M), (d)At room temperature, the root mean square speed of CO2 is ~620 m/s,(e)The kinetic energy of one mole monoatomic perfect gas is (3/2)RT 9.1eV is equivalent to (a)3.84×10^-23 kcal,(b)1.6×10^-19 cal,(c)1.6×10^-19 erg,(d)23.06 kcal/mol,(e)1.6 kcal/mol,(f)8065 cm-1 10.The standard enthalpy of combustion of cyclopropane is -2091 KJ/mol. The standard enthalpy of formation for CO2(g) and H2O(l) is -393.51 and -285.83 KJ/mol, respectively. Calculate the enthalpy of formation of cyclopropane to be (a)53KJ/mol,(b)42KJ/mol,(c)102KJ/mol,(d)33KJ/mol,(e)none of above 11.Which of the following statements are correct (a)Te Boyle's law states that when P→0, PVm=constant at a fixed temperature,(b)STP stands for standard ambient temperature and pressure,(c) Dalton's law states that at constant P and T the volume of the gas is proportional to the number of molecules,(d)Charles law states that at constant pressure the volume of a fixed amount of gas is proportional to temperature,(e)Dalton's law states that the pressure exerted by a mixture of perfect gases is the sum of the pressures exerted by the individual gases occupying the same volume alone. 12.In which of the following processes is the work done by the system the largest at 25度C? (a)An isothermal free expantion of the ideal gas from 1L to 10L (b)An isothermal expansion of an ideal gas from 1L to 10L against an poopsing pressure of 1atm (c)An isothermal expansion of an ideal gas from 1L to 10L against an poopsing pressure of 5atm (d)An isothermal reversible expansion of an ideal gas from 1L to 10L (e)The work is the same for processes a-d _ 13.Given the number of collisions per unit time, Z as Z = √2 σc(p/kT) where _ c is the mean speed. Accordingly, the mean-free path λ(distance/collision ) can be expressed as _ _ (a)√2 σ/kT,(b)kT/√2,(c)kT/(√2 σP),(d)√2 σPc,(e)kT/(√2 c) 14.(continue on 13)In a fix volume when temperature increases λ is then (a)increased,(b)decreased,(c)unchanged,(d)undetermined 15.A solution contains the ions Ag+, Pb2+, and Ni2+. Dilute solutions of NaCl , Na2SO4, and Na2S are available to separate the positive ions from each other. To separate the ions, in which order should the solutions be added? (a)Na2SO4, NaCl, Na2S,(b)Na2SO4, Na2S, NaCl,(c)Na2S, NaCl, Na2SO4,(d)NaCl, Na2S, Na2SO4, (e)NaCl, Na2SO4, Na2S 16.Diesel fuel normally uses petroleum of (a)C5-C10,(b)C10-C18,(c)C15-C25,(d) >C25,(e)cannot be determined 17.A silver concentrantion cell is set up at 25度C with 1.0M AgNO3 in the left compartment and 1.0M NaCl along with excess AgCl(s) in the right compartment. The measured cell potential is 0.58V. Calculate the Ksp value for AgCl at 25度C. (a)2.2×10^-15,(b)1.0×10^-8,(c)3.2×10^-32,(d)3.2×10^-12,(e)none of above, (f)1.6×10^-10 18.The ε0 for the half-reaction 2 H2O + 2e- → H2 + 2OH- is measured to be -0.829V, The standard free energy ΔGf0 for H2O(l)=-237KJ/mol, estimate the ΔGf0 value for OH-(aq), taking ΔGf0 of e- = 0. (a)45.2kcal/mol,(b)42.5KJ/mol,(c)-37.4kcal/mol,(d)-210.3KJ/mol,(e)-22.3kcal /mol 19.(1)PbO2 + 4H+ + SO4 2- + 2e- → PbSP4(s) + 2H2O ε0 = ? (2)PbO2 + 4H+ + 2e- → Pb2+ + 2H2O ε0 = 1.46 Knowing Ksp of PbSO4 = 1.7×10^-8, ε0 value for the reaction (1) is calculated to be (a)1.69,(b)1.23,(c)-1.32,(d)0.83,(e)-1.85,(f)0.52 20.Benzene has a melting point of 5.5度C and an enthalpy of fusion of 10.4KJ/ mol at 25度C. The molar heat capacities at constant pressure for solid and liquid benzene are 100.4 J/Kmol and 133.0 J/K, respectively. Calculate the ΔSsys of freezing for benzene at 5.5度C. (a)-36.3J/K,(b)-9.55J/K,(c)-41J/K,(d)-33.8J/K,(e)-52.3J/K