山东大学 Physical Chemistry(2)课程试卷 2020-2021学年Fa学期 哥□一二三四五[大[七八九十‖总分厦总分人 follow? (A)L-H mechanism, (B)L-R mechanism 2020-2021 Academic Year. Fall Semeste (C) Unimolecular reaction; (D)No definite conclusion. Final Exam of Physical Chemistry(2)-B [I-5] For ionic atmosphere put forward by Debye-Huckel, which of the following factors was not included in the model? Constants: Faraday constant F=96500 C mol: Avogadros constant L-6.022 x 10mol:I(A)Electrolyte dissociates completely at infinite dilution, Speed of light in vacuum C=2.998×10°ms; Plank constant h=6.626×10Js Atomic mass: Li: 6.94: Sn: 118 (C) Each ion is surrounded by its counter-ions, Bond energy(/J mol- ): H-H: 436 H: 298, H: 151; C-C: 332; C-C: 611 (D)There is no other interaction between cation and anion except of electrostatic Electrode potential (/V): o(Cl/Cr)=1. 358; P(OH/Ha)--0827; P(Ag*/Ag)0. 799. attraction [1-6] For concentration cell: Zn(s)IznSO. (=0. 02)II ZnSO4(=0.2)IZn(s),its Please write all your answers on the ANSWER SHEet electromotive force at 298 K is (A)0.059V,(B)-0.059V,(C)0.0295V(D)-0.0295V 分■鲁 [1-7 Which of the following statements is correct? 1. Choose the best answer for the following questions(2 points for each question, (A)A second order reaction must be a bi-molecular reaction B)a bi-molecular reaction must be a second order reaction, totally 20 points) (C) For second order reaction, its half-life decreases with increasing the initial [l-l] In order to increase the working voltage of a Hx-Oz fuel cell, which of the following ease the pressure of H2; (B)increase the pressure of O, (C) increase the pH of (D) The reaction order is al ways positive. the solution;(D)increase the conductivity of electrolyte. possible collision direction and the structure of transition state? (B) [1-2] For gaseous decomposition of 2Hl- Hz+lz, its mechanism is (1)H+hy—→H+(2)H+H→→H+1;(3)I+I+M→→l2+M The activation energy of which step is the lowest B●● (A)(1)(B)(2)(C)(3)(D) all the The slope of the linear part of which electrolyte is the largest? [1-9] When a Hg thermometer is broken, Hg appears as small ball on concrete surface(s), (A)KCl; (B)CaCl2, (C)MgSO4, (D)AlCl; this means [1-4] For a heterogeneous catalyzed reaction A+B-P, when increasing the ratio of nA/nB, the reaction rate first increases and then decreases. Then which mechanism does this reaction (A)oHe-g+ dHB-sO-g 第
2020-2021 学年 Fall 学期 题号 一 二 三 四 五 六 七 八 九 十 总分 总分人 得分 2020-2021 Academic Year, Fall Semester Final Exam of Physical Chemistry (2)-B ---------------------------------------------------------------------------------------------- Constants: Faraday constant F = 96500 C mol-1 ; Avogadro’s constant L = 6.022 1023 mol-1 ; Speed of light in vacuum C = 2.998 108 m s-1 ; Plank constant h = 6.626 10-34 J s; Atomic mass: Li: 6.94; Sn: 118.7; Bond energy (/kJ mol-1 ): H⎯H: 436 H⎯I: 298; I⎯I: 151; C⎯C: 332; C==C: 611. Electrode potential (/V):(Cl2/Cl- )=1.358; (OH- /H2)=-0.827; (Ag+ /Ag)=0.799. --------------------------------------------------------------------------------------------- Please write all your answers on the ANSWER SHEET --------------------------------------------------------------------------------------------- 得分 阅卷人 1. Choose the best answer for the following questions (2 points for each question, totally 20 points) [1-1] In order to increase the working voltage of a H2-O2 fuel cell, which of the following measures is not effective? (A) Increase the pressure of H2; (B) increase the pressure of O2; (C) increase the pH of the solution; (D) increase the conductivity of electrolyte. [1-2] For gaseous decomposition of 2HI⎯→ H2 + I2, its mechanism is (1) HI + h ⎯→ H + I; (2) H + HI ⎯→ H2 + I; (3) I + I + M ⎯→ I2 + M The activation energy of which step is the lowest? (A) (1); (B) (2); (C) (3); (D) all the same [1-3] As pointed out by Lewis, for ln ~ , there is a linear relation at low ionic strength. The slope of the linear part of which electrolyte is the largest? (A) KCl; (B) CaCl2; (C) MgSO4; (D)AlCl3 [1-4] For a heterogeneous catalyzed reaction A+B ⎯→ P, when increasing the ratio of nA/nB, the reaction rate first increases and then decreases. Then, which mechanism does this reaction follow? (A) L-H mechanism; (B) L-R mechanism; (C) Unimolecular reaction; (D) No definite conclusion. [1-5] For ionic atmosphere put forward by Debye-Hückel, which of the following factors was not included in the model? (A) Electrolyte dissociates completely at infinite dilution; (B) All ions are hydrated; (C) Each ion is surrounded by its counter-ions; (D) There is no other interaction between cation and anion except of electrostatic attraction. [1-6] For concentration cell: Zn(s)ZnSO4(a=0.02)ZnSO4(a=0.2)Zn(s), its electromotive force at 298 K is (A) 0.059 V; (B) -0.059 V; (C) 0.0295 V; (D) -0.0295 V [1-7] Which of the following statements is correct? (A) A second order reaction must be a bi-molecular reaction; (B) A bi-molecular reaction must be a second order reaction; (C) For second order reaction, its half-life decreases with increasing the initial concentration. (D) The reaction order is always positive. [1-8] For gaseous decomposition of N2O, it is second-order at lower pressure. What is the possible collision direction and the structure of transition state? （B） [1-9] When a Hg thermometer is broken, Hg appears as small ball on concrete surface (s), this means (A)Hg-g+ Hg-s s-g; (C)Hg-g s-g. 山东大学 Physical Chemistry (2) 课程试卷 学院 专业 级 学号 姓名 … … … … … … … … … … … … … … 密 … … … … … … … … … … 封 … … … … … … … … … … 线 … … … … … … … … … … … … … 第 1 页 共 3 页
山东大学 Phys ical Chemistry(2)课程试卷 2020-2021学年_Fa|学期 [1-10] At which conditions will the viscosity of a protein solution increase? d that the scattering intensity of this solution is times higher (B) In salting-out state, than the unknown one. Then the concentration of the unknown S sol is possibly of (C)Protein at its isoelectric point; (D)solution at higher temperature. 0.0125 mol dm 26] At certain conditions, the electrophoresis distance of serum(血清蛋白) varies with pH Il. Fill the blanks with the best answers(2 points for one question, Totally 22 Ax/cm 0.936 0.238 0.234 The isoelectric point is 4.51, At low pH, serum is tively/negatively) 密 [2-1]For polybutadiene rubber used in tire industry, what kind of light can cause aging( charged. 化)oft?428.76mm [2-2]Hg sol can be prepared by purging Hg vapor into dilute NaoH solution in which OH- 分■人 serving as stabilizer. The structure notation of the as-prepared Hg sol is__I(Hgho-nOH(n- Ill. Give brief answer to the following questions:(Totally 28 points) r)Na]"xNa If this Hg sol can be precipitated by 2 mmol dm"MgSO4, then the 3-11 [16 points] For I g hydrophilic adsorbent with micropores(ffL) its adsorpt precipitating value of MgClz isotherm for water at 298.2 K is shown in the following figure. It was found that Vm,I18.0 [2-3]In Cd-Ni battery, cd powder is used as the negative material and Ni( OOH) as the positive cm, Vm, 25.2 cm(STP). For water at 298.I K, the saturated pressure is 3. 168 kPa, pl is material with concentrated KOH solution serving as the electrolyte. Ni net is used as current 38 kPa, the surface tension is 71.94 mN m, and density is 0.997 g cm collector for both positive and negative electrodes. Please write the cell notation of this battery. ()[2 points] Please draw the corresponding desorption isotherm in the figure. Ni(s)Icd(s)I cd(oHhl KoH Ni(OH INi(ooH)INi(s) electrode reaction occurring on the positive plate during discharge. Ni(OOH)+H:O+ le -Ni(OH)+ OH- The theoretical electrochemical capacity of Ni(ooH)is 292.4 mAh g[Ni=S8.68: O=16.00, H-1.008]. The standard electrode potential of oe(Cd(OH)/Cd) is -0.783 V, oe(Cd*/Cdi-0403 V, the ksp of CH(OH) at 298.2K is 96500916883.6=2924mAhg [2-4]For a certain reaction A-P, its rate constant is 2.31x10-2s-l mol-l dm. If the initial/4)6 points] Please give explanation to the shape of adsorption isotherm by defining the concentration of A is 1.00 mol dm-3 then the half-life of the reaction is 43.29 s process corresponds to(), (2)and(3) [2-5] In order to determine the concentration of an unknown S sol, a student synthesized a s () monolayer adsorption; (2)capillary condensation; (3)surface liquidation. 第2页共3页
2020-2021 学年 Fall 学期 [1-10] At which conditions will the viscosity of a protein solution increase? (A) In salting-in state; (B) In salting-out state; (C) Protein at its isoelectric point; (D) solution at higher temperature. 得分 阅卷人 II. Fill the blanks with the best answers (2 points for one question, Totally 22 points) [2-1] For polybutadiene rubber used in tire industry, what kind of light can cause aging (老 化) of it? ___ 428.76 nm ___. [2-2] Hg sol can be prepared by purging Hg vapor into dilute NaOH solution in which OHserving as stabilizer. The structure notation of the as-prepared Hg sol is ___ [(Hg)mnOH- (nx)Na+ ] x- xNa+___. If this Hg sol can be precipitated by 2 mmol dm-3 MgSO4, then the precipitating value of MgCl2 _________ (>, <, =) 2 mmol dm-3 . [2-3] In Cd-Ni battery, Cd powder is used as the negative material and Ni(OOH) as the positive material with concentrated KOH solution serving as the electrolyte. Ni net is used as current collector for both positive and negative electrodes. Please write the cell notation of this battery. _Ni(s)Cd(s)Cd(OH)2KOHNi(OH)2Ni(OOH)Ni(s)______________. Write the electrode reaction occurring on the positive plate during discharge.__Ni(OOH) + H2O + 1e- ⎯→Ni(OH)2 + OH-_____. The theoretical electrochemical capacity of Ni(OOH) is 292.4__mAh g-1 .[Ni=58.68; O=16.00, H=1.008]. The standard electrode potential of (Cd(OH)2/Cd) is -0.783 V, (Cd2+/Cd)=-0.403 V, the ksp of Cd(OH)2 at 298.2K is __1.42×10-13________. (96500/91.688)/3.6 = 292.4 mAh g-1 [2-4] For a certain reaction A⎯→P, its rate constant is 2.3110-2 s -1 mol-1 dm3 . If the initial concentration of A is 1.00 mol dm-3 , then the half-life of the reaction is __43.29 s_____. [2-5] In order to determine the concentration of an unknown S sol, a student synthesized a S sol of 0.1 mol dm-3 , and found that the scattering intensity of this solution is 8 times higher than the unknown one. Then the concentration of the unknown S sol is possibly of _0.0125___ mol dm-3 . [2-6] At certain conditions, the electrophoresis distance of serum (血清蛋白) varies with pH pH 3.76 4.20 4.82 5.58 x/cm 0.936 0.238 0.234 0.710 The isoelectric point is __4.51__. At low pH, serum is _______(positively/negatively) charged. 得分 阅卷人 III. Give brief answer to the following questions: (Totally 28 points) [3-1] [16 points] For 1 g hydrophilic adsorbent with micropores (微孔), its adsorption isotherm for water at 298.2 K is shown in the following figure. It was found that Vm, 1= 18.0 cm3 , Vm, 2= 25.2 cm3 (STP). For water at 298.1 K, the saturated pressure is 3.168 kPa, p1 is 2.338 kPa, the surface tension is 71.94 mN m-1 , and density is 0.997 g cm-3 . (1) [2 points] Please draw the corresponding desorption isotherm in the figure. (2)[6 points] Please give explanation to the shape of adsorption isotherm by defining the process corresponds to (1), (2) and (3). (1) monolayer adsorption; (2) capillary condensation; (3) surface liquidation. 山东大学 Physical Chemistry (2) 课程试卷 学院 专业 级 学号 姓名 … … … … … … … … … … … … … … 密 … … … … … … … … … … 封 … … … … … … … … … … 线 … … … … … … … … … … … … … 第 2 页 共 3 页
山东大学 Physica| Chemistry(2)课程试卷 2020-2021学年 ()[4 points] Determine the rate law of the reaction; (2)[4 points Suggest the possible mechanism; A2+B→→→Lrd.s (3)[2 points] Please give explanation to the different part in desorption isotherm. In P- 2o M Evaporation of water from hydrophilic micropore is difficult (3)[4 points] Verify the proposed mechanism. (4)[2 points] If water vapor can be treated as ideal gas, and the diameter of water molecule is dI 0. 4 nm. calculate the mass specific area of this adsorbent in m'g. 18.0×1024×6022×1023×3.1416×0.04×1018mlg=60.75mg 分■人 (5)14 points] Please calculate the radius of the micropores in the adsorbent and their total volume T. Calculation(Totally 30 points 7194×103x18 14-11[18 points] At 298 K, a 1.00 mol kg" NaCl solution with mean activity coefficient aa 688.314×2982×0997× 0.658 was electrolyzed with a 1.00 cm-Ii serving as the anode and a 1.00 cm Fe as the r=345mm.72×103224×180.997=5.8×10m3 cathode. The distance between the anode and cathode is 2.00 cm. The electric conductivity [3-2][12 points] For a gaseous reaction 2A+2B-L+M taking place in a container with of the solution is 0. 10 S cm. Upon passage of a 0.10 A current, the polariz temperature and volume, its rate law has evolution on the Ti electrode is negligible while the polarization of Hz on Fe obeys Tafel 14△=kpp equation of n-a+blog[J/A cm- where a is 0.73 V, b is 0.11 V. (1)(4 points] Calculate the resistance polarization(R)of the cell; The experimental results are listed in the Table A,=P,0 (2)[2 points] Determine the electrochemical (or activation) polarization of hydrogen 2/s pAokPa ro/kPa s-l electrode(n): n=0.62 V (3)[2 points] The reversible electrolysis voltage of this Nacl solution is 1,782 V. Then, what is the effective decomposition voltage of 1.00 mol kg- NaCl(Vett) ro is the initial rate er=1.782+0.62+2.0=44V 页共3页
2020-2021 学年 Fall 学期 (3) [2 points] Please give explanation to the different part in desorption isotherm. Evaporation of water from hydrophilic micropore is difficult (4) [2 points] If water vapor can be treated as ideal gas, and the diameter of water molecule is 0.4 nm. calculate the mass specific area of this adsorbent in m2g -1 . 18.010-3 /22.4 ×6.022×1023×3.1416×0.04×10-18 m2 /1 g = 60.75 m2 /g (5) [4 points] Please calculate the radius of the micropores in the adsorbent and their total volume. r=3.45 nm. 7.2×10 -3 /22.4 ×18 /0.997 = 5.8×10 -9 m3 [3-2] [12 points] For a gaseous reaction 2A + 2B ⎯→ L + M taking place in a container with constant temperature and volume, its rate law has the form The experimental results are listed in the Table. pA,0= pB,0 pB,0>>pA,0 ptotal,0/kPa t1/2/s pA,0/kPa r0/kPa s-1 47.4 82 40.0 0.137 32.4 176 20.3 0.034 r0 is the initial rate. (1) [4 points] Determine the rate law of the reaction; =2; =1 (2) [4 points] Suggest the possible mechanism; 2AA2 A2+B⎯→L r.d.s L+B⎯→M (3) [4 points] Verify the proposed mechanism. ; ; 得分 阅卷人 IV. Calculation (Totally 30 points): [4-1] [18 points] At 298 K, a 1.00 mol kg-1 NaCl solution with mean activity coefficient = 0.658 was electrolyzed with a 1.00 cm2 Ti serving as the anode and a 1.00 cm2 Fe as the cathode. The distance between the anode and cathode is 2.00 cm. The electric conductivity of the solution is 0.10 S cm-1 . Upon passage of a 0.10 A current, the polarization of Cl2 evolution on the Ti electrode is negligible while the polarization of H2 on Fe obeys Tafel equation of =a+blog[J/A cm-2 ], where a is 0.73 V, b is 0.11 V. (1) [4 points] Calculate the resistance polarization (R) of the cell; (1) =20 , R= 2 V (2) [2 points] Determine the electrochemical (or activation) polarization of hydrogen electrode (a); a=0.62 V (3) [2 points] The reversible electrolysis voltage of this NaCl solution is 1.782 V. Then, what is the effective decomposition voltage of 1.00 mol kg-1 NaCl (Veff); Veff = 1.782 + 0.62 + 2.0 = 4.4 V 山东大学 Physical Chemistry (2) 课程试卷 学院 专业 级 学号 姓名 … … … … … … … … … … … … … … 密 … … … … … … … … … … 封 … … … … … … … … … … 线 … … … … … … … … … … … … … 第 3 页 共 3 页
山东大学 Physica| Chemistry(2)课程试卷 20202021学年_Fa|学期 (4)[6 points] After electrolysis for 30 min, write the electrode reaction of the cathode and determine how many mole of NaoH can be produced in the cathodic compartment. How many electric energy is consumed? what is the energy efficiency of this electrolysis? 0.10Acm-2×100cm2×30×60%6500=1.865×103 mol NaOH 0.10Acmr2×100cm2×30min×60s×44V=0.792kJ 14-21[14 points] There are two first-order competing reactions A-ii+z (side reaction) (1)(4 points] If the side reaction can be neglected, at 800 K, half-life of A is 1386s, then hot long does it taken to achieve 99% conversion? 0691,=5:0×103s35hm5=k,1=9210s (2)[2 points] If the side reaction cannot be neglected, at 800 K for 99% conversion need 837 s, what is the apparent rate constant? k=(k+k2厘=5.50×103s (3)(4 points] At 800K, if kI=4.7x10-3sI, what is kz? What is the ratio Y/Z? k=0.8×103s1;Y=5.88 (4)[2 points) If the pre-exponential factor of these two reactions is just the same, Ea, I 80 k 线 mol-l, what is Eaz? (5)(2 points] If we want to increase yield of Y, should we perform this reaction at higher or At lower temperature
2020 -2021 学年 Fall 学期 ( 4) [6 points] After electrolysis for 30 min, write the electrode reaction of the cathod e and determine how many mole of NaOH can be produced in the cathodic compartment. How many electric energy is consumed? What is the energy efficiency of this electrolysis? 0.10 A cm - 2 1.00 cm 2 30 60/96500 = 1.865 10 - 3 mol NaOH 0.10 A cm - 2 1.00 cm 2 30 min 60 s 4.4 V = 0.792 kJ. 1.782/4.4 = 40.5% [ 4 -2] [14 points] There are two first -order competing reactions: (1) [4 points] If the side reaction can be neglected, at 800 K, half-life of A is 138.6 s, then how long does it taken to achieve 99% conversion? ， k=5.0×10 - 3 s - 1 ; , t =921.0 s (2) [2 points] If the side reaction cannot be neglected, at 800 K for 99% conversion need 837 s, what is the apparent rate constant? k=(k1+k2)=5.50×10-3 s-1 (3) [4 points] At 800K, if k 1=4.7×10 - 3 s - 1 , what is k2? What is the ratio Y/Z? k2=0.8 ×10 - 3 s - 1 ; Y/Z=5.88 (4) [2 points] If the pre -exponential factor of these two reactions is just the same, Ea,1=80 kJ mol - 1 , what is Ea, 2 ? Ea,1=91.78 kJ mol - 1 , (5) [2 points] If we want to increase yield of Y, should we perform this reaction at higher or lower temperature? At lower temperature. 山东大学 Physical Chemistry (2) 课程试卷 学院 专业 级 学号 姓名 ……………………………………密…………………………封…………………………线…………………………………
