《无机及分析化学(化工版)第一章习题及答案.pdf》由会员分享,可在线阅读,更多相关《无机及分析化学(化工版)第一章习题及答案.pdf(14页珍藏版)》请在taowenge.com淘文阁网|工程机械CAD图纸|机械工程制图|CAD装配图下载|SolidWorks_CaTia_CAD_UG_PROE_设计图分享下载上搜索。
1、1.NO 是汽车尾气的主要污染源,有人设想以加热分解的方法来消除之2NON2O2试从热力学角度判断该方法能否实现?解:r rH Hm m 90.252 180.5kJmol-1 r rS Sm m191.61 205.14 210.762 24.62 Jmol-1K-1该反应要实现必须 r rG Gm m0所以高温不利2.设汽车内燃机内温度因燃料燃烧反应达到 1573 K,试计算此温度时下列反应1/2 N2(g)1/2 O2(g)NO(g)的rGm和K解:rGmBfHm1573BSm113 90.251573(210.761191.61205.138)10 70.77kJ/mol22rGm R
2、T lnK70.77 8.3141031573lnKK 4.461033.蔗糖(C12H22O11)在人体内的代谢反应为:C12H22O11(s)+12O2(g)12CO2(g)+11H2O(l)假设其反应热有30%可转化为有用功,试计算体重为70kg的人登上3000m高的山(按有效功计算),若其能量完全由蔗糖转换,需消耗多少蔗糖?解:A=70kg3000m=2.1105kgm=2.11059.8J=2.1103kJrH=2.1103kJ/30%=7.0103kJrHm=11(285.830 kJmol1)+12(393.509 kJmol1)(2222 kJmol1)=5644kJmol1=
3、rH/rHm=7.0103kJ/5644kJmol1=1.24molm(C12H22O11)=1.24342.3=425g4.利用附录 III 的数据,计算 298.15 K 时下列反应的rHm(1)Ca(OH)2(s)+CO2(g)CaCO3(s)+H2O(l)(2)CuO(s)+CO(g)Cu(s)+CO2(g)(3)2SO2(g)+O2(g)2SO3(g)(4)CH3COOH(l)+2O2(g)2CO2(g)+2H2O(l)解:rHm HBfm(1)rHm=(1206.92)+(285.83)(986.09)(393.51)=113.15kJmol1(2)rHm=0+(393.51)-(
4、157.3)(110.53)=-125.68 kJmol1(3)rHm=2(395.72)(296.83)=197.78 kJmol1(4)rHm=2(393.51)+2(285.83)(484.5)=874.18 kJmol15.已知下列化学反应的反应热:(1)C2H2(g)+5/2O2(g)2CO2(g)+H2O(g);rHm=1246.2 kJmol1(2)C(s)+2H2O(g)CO2(g)+2H2(g);rHm=+90.9 kJmol1(3)2H2O(g)2H2(g)+O2(g);rHm=+483.6 kJmol1求乙炔(C2H2,g)的生成热 fHm。解:反应 2(2)(1)2.5
5、(3)为:2C(s)+H2(g)C2H2(g)fHm=2rHm(2)rHm(1)2.5rHm(3)=290.9(1246.2)2.5483.6 kJmol1=219.0 kJmol16.高炉炼铁中的主要反应有:C(s)+O2(g)CO2(g)1/2CO2(g)+1/2C(s)CO(g)CO(g)+1/3Fe2O3(s)2/3Fe(s)CO2(g)(1)分别计算 298.15K 时各反应的rHm和各反应rHm值之和;(2)将上列三个反应式合并成一个总反应方程式,应用各物质 298.15K 时的fHm数据计算总反应的反应热,与计算结果比较,并作出结论。解:(1)rHmBfHmrHm(1)393.5
6、1 0 0 393.51kJmol11rHm(2)110.53(393.51)0 86.23kJmol121rHm(3)0(393.51)(110.53)(824.2)8.25kJmol13(1)rHm(2)rHm(4)=315.53kJmol1rHmrHm(2)rHm31BfHm 0(393.51)(824.2)00 315.53kJmol123无论是一步反应或多步反应化学反应热效应总和总是相等的。7.利用附录 III,判断下列反应 298.15K 能否自发向右进行。(1)2 Cu+(aq)Cu2+(aq)+Cu(s)(2)AgCl(s)+Br(aq)AgBr(s)+Cl(aq)(3)4NH
7、3(g)+5O2(g)4NO(g)+6H2O(g)(4)4NO(g)+6H2O(g)4NH3(g)+5O2(g)解:rGm BfGm(1)r rG Gm m=65.49+049.982=34.47 kJmol10能自发反应(2)r rG Gm m=(96.9)+(131.22)(109.79)(103.96)=14.38 kJmol10能自发反应(3)r rG Gm m=4(86.55)+6(228.58)4(16.45)0=959.48 kJmol10(4)r rG Gm m=4(16.45)+04(86.55)6(228.58)=959.48kJmol108.由软锰矿二氧化锰制备金属锰可采
8、取下列两种方法:(1)MnO2(s)+2H2(g)Mn(s)+2H2O(g);(2)MnO2(s)+2C(s)Mn(s)+2CO(g);上述两个反应在 25,100 kPa 下是否能自发进行?如果考虑工作温度愈低愈好的话,则制备锰采用哪一种方法比较好?解:(1)rGm(298K)(466.14)2(228.58)8.98kJmol01(2)r rG Gm m(298K K)(466.14)2(137.17)191.8kJmol10所以两个反应在 25,100 kPa 下都不能自发进行。一式的rHm=36.39 kJmol11rSm=95.24 kJmolT1=382K一式的rHm=298.98
9、 kJmol11rSm=362.28 kJmol T2=825K仅考虑温度时,选(1)有利是大于零还是小于零:9.定性判断下列反应的rSm(1)Zn(s)+2HCl(aq)ZnCl2(aq)+H2(g)(2)CaCO3(s)CaO(s)+CO2(g)(3)NH3(g)+HCl(g)NH4Cl(s)(4)CuO(s)+H2(g)Cu(s)+H2O(l)解:(1)rSm0(2)r rS Sm m0(3)rSm0(4)r rS Sm m010.糖在人体中的新陈代谢过程如下:C12H22O11(s)+12O2(g)12CO2(g)+11H2O(l)若反应的吉布斯函数变rGm只有 30%能转化为有用功,
10、则一匙糖(3.8g)在体温 37时进行新陈代谢,可得多少有用功?(已知 C12H22O11的fHm=2222kJmol1 Sm=360.2Jmol1K1)解:C12H22O11(s)+12O2(g)12CO2(g)+11H2O(l)fHm/kJmol122220393.509285.830Sm/Jmol1K1360.2205.138213.7469.91rHm=11(285.830)+12(393.509)(2222)kJmol1=5645kJmol1rSm=1169.91+12213.7412205.138360.2 Jmol1K1=512.03 Jmol1K1rGm=rHmTrSm=564
11、5kJmol1310.15K512.03103kJmol1K1=5803kJmol1=nB/B=3.8g/342gmol1=1.11102molW有用功=30%rG=30%rGm=30%(5803kJmol1)1.11102mol=19kJ负号表示系统对环境做功。11.已知反应2H2(g)+2NO(g)2H2O(g)+N2(g)的速率方程 v=k c(H2)c2(NO),在一定温度下,若使容器体积缩小到原来的 1/2 时,问反应速率如何变化?解:v=k c(H2)c2(NO)v2=k 2c(H2)2c(NO)2=8 v反应速率将为原速率得 8 倍。12.某基元反应 A+B C,在 1.20L
12、溶液中,当 A 为 4.0 mol,B 为 3.0mol 时,v 为 0.0042molL1s1,计算该反应的速率常数,并写出该反应的速率方程式。解:v=kcAcBk=0.0042moldm3s1/(4.0 mol/1.20dm3)(3.0mol)/1.20dm3=3.5104 mol1dm3s113.已知反应 HI(g)+CH(3g)CH4+I2(g)在 157oC 时的反应速率常数 k=1.710-5Lmol-1s-1,在 227oC 时的速率常数 k=4.010-5Lmol-1s-1,求该反应的活化能。解:由lnk k1k k2=Ea 11 RT1T2得Ea1.710511ln()8.3
13、14 4305004.0105Ea=21.85 kJmol114.某病人发烧至 40时,使体内某一酶催化反应的速率常数增大为正常体温(37)的 1.25 倍,求该酶催化反应的活化能?解:lnEa111 1.258.31410-3kJmol1K1310K313KEa=60.0 kJmol115.某二级反应,其在不同温度下的反应速率常数如下:T/K645675715750k 103/mol1 Lmin16.1522.077.5250(1)作 lnk1/T 图计算反应活化能 Ea;(2)计算 700 K 时的反应速率常数 k。解:(1)画图略,Ea=140kJmol1;k1.410511()(2)l
14、n48.3147007157.5510k 4.56104mol1 Lmin116.写出下列各化学反应的平衡常数 K表达式:1)HAc(aq)3)C(s)+H2O(g)5)CaCO3(s)H+(aq)+Ac(aq)2)Cu2+(aq)+4NH3(aq)CO(g)+H2(g)4)AgCl(s)CaO(s)+CO2(g)2Mn2(aq)+5SO42(aq)+3H2O(l)Cu(NH3)4(aq)Ag(aq)+Cl(aq)6)2MnO4(aq)+5SO32(aq)+6H(aq)解:1)K=(c(H+)/c)(c(Ac)/c)(c(HAc)/c)12)K=(c(Cu(NH3)4/c(c(Cu2+)/c)
15、1(c(NH3)/c)43)K=(p(CO)/p)(p(H2)/p)(p(H2O)/p)14)K=(c(Ag+)/c)(c(Cl)/c)5)K=p(CO2)/p6)K=(c(Mn+2)/c)2(c(SO42)/c)5(c(MnO41)/c)2(c(SO32)/c)5(c(H+)/c)617.已知下列化学反应在 298.15K 时的平衡常数:(1)2N2(g)+O2(g)(2)N2(g)+2O2(g)计算反应 2 N2O(g)+3O2(g)2N2O(g);K1=4.810372NO2(g);K2=8.810194NO2(g)的平衡常数K。解:(2)2(1)为所求反应:2 K K3(K K2)/K
16、 K1(8.81019)2/4.810371.6.18.已知下列反应在 298.15K 的平衡常数:1)SnO2(s)+2H2(g)2)H2O(g)+CO(g)2H2O(g)+Sn(s);K1=21H2(g)+CO2(g);K2=0.034Sn(s)+2CO2(g)在 298.15K 时的平衡常数 K。计算反应2CO(g)+SnO2(s)解:反应(1)+2(2)为所求反应:K=K1(K2)2=210.0342=2.410219.密闭容器中反应2NO(g)+O2(g)2NO2(g)在 1500K 条件下达到平衡。若始态p(NO)=1 50kP a,p(O2)=450kP a,p(N O2)=0;
17、平衡时p(N O2)=25kP a。试计 算平衡时 p(NO),p(O2)的分压及平衡常数 K。解:V、T 不变,p n,各平衡分压为:p(NO)=15025=125kPa;p(O2)=45025/2=437.5kPaK=(p(NO2)/p)2(p(NO)/p)2(p(O2)/p)1=(25/100)2(125/100)2(437.5/100)1=9.110320.密闭容器中的反应 CO(g)+H2O(g)CO2(g)+H2(g)在 750K 时其 K=2.6,求:(1)当原料气中 H2O(g)和 CO(g)的物质的量之比为 11 时,CO(g)的转化率为多少?(2)当原料气中 H2O(g)C
18、O(g)为 41 时,CO(g)的转化率为多少?说明什么问题?解:(1)V、T 不变CO(g)+H2O(g)CO2(g)+H2(g)起始 n/mol1100平衡 n/mol1x1xxxn=2(1x)+2x=2平衡分压1 xp总1 xp总xp总xp总2222K=(p(H2)/p)(p(CO2)/p)(p(H2O)/p)1(p(CO)/p)12.6=(x)2(1 x)222x=0.617(CO)=61.7%(2)x2/(1x)(5x)=2.6x=0.92(CO)=92%H2O(g)浓度增大,CO 转化率增大。21.在 317K,反应N2O4(g)2NO2(g)的平衡常数K=1.00。分别计算当体系
19、总压为 400kPa和 800kPa 时 N2O4(g)的平衡转化率,并解释计算结果。解:N2O4(g)2NO2(g)平衡时1-2平衡总体系物质量1p总为总压力,则 p(N2O4)=p总1 2;p(NO2)=p总1 1 2 p p/p p 2 2总总 p p(NONO2)/p p 1 K K 1 p p(N N2O O4)/p p p p总总/p p1 把总压为 400kPa 和 800kPa,p p100 kPa 分别代入上式可求得总压 400kPa 时,124.3%总压 800kPa 时,217.4%增大压力,平衡向气体分子数减少的方向移动,(N2O4)下降。22.某反应 3A(g)+B(
20、g)2C(g),按 V(A):V(B)=3:1 配制原料气。在某种催化剂作用下,于温度为 T、压力为 20.0 kPa 时达到平衡。这时 C(g)的体积分数为 6.00%。试计算在此温度下该反应的标准平衡常数K。解:3A(g)+B(g)2C(g)平衡时气体体积百分比70.5%23.5%6206%2)(p p/p p)100C CK K 1.09 3 2070.5%2023.5%(p pA A/p p)(p pB B/p p)()3()100100 2(23.已知尿素 CO(NH2)2的fGm=197.15kJmol1,求尿素的合成反应2NH3(g)+CO2(g)H2O(g)+CO(NH2)2(
21、s)在 298.15K 时的rGm和K。解:rGm vBfGm(B)=(228.58)+(197.15)2(16.45)(394.36)=1.53kJmol1 r rG Gm m RTRT lnlnK K 所以K K(298.15K)=0.53924.25时,反应 2H2O2(g)2H2O(g)+O2(g)的rHm为210.9kJmol1,rSm为 131.8Jmol1K1。试计算该反应在 25和 100时的K,计算结果说明问题。解:r rG Gm m(298.15K).r rH Hm m 298.15 r rS Sm m210.9103298.15131.82.502105Jmol1 r r
22、G Gm m(373.15K).r rH Hm m373.15 r rS Sm m210.9103373.15131.82.601105Jmol1 r rG Gm m RTRT lnlnK K 所以K K(298.15K)=6.81043 K K(373.15K)=2.51036H2O2分解反应为放热反应,随着温度升高,平衡向左移动。25.在一定温度下 Ag2O 的分解反应为Ag2O(s)2Ag(s)+1/2O2(g)假定反应的rHm,rSm不随温度的变化而改变,估算Ag2O 的最低分解温度和在该温度下的 p(O2)分压是多少?解:rHm=31.05kJmol111rSm=242.5+205.
23、138/2121.3Jmol K=66.269Jmol1K1T=rHm/rSm=31.05kJmol1/66.269103kJmol1K1=468.5 K此时,rGm=0 kJmol1,K=1,K=(p(O2)/p)1/2,p(O2)=100kPa。26:乙苯(C6H5C2H5)脱氢制苯乙烯有两个反应:(1)氧化脱氢C6H5C2H5(g)+1/2 O2(g)(2)直接脱氢C6H5C2H5(g)C6H5CHCH2(g)+H2O(g)+H2(g)C6H5CHCH2(g)若反应在 298.15K 进行,计算两反应的平衡常数,试问哪一种方法可行?C6H5C2H5(g)C6H5CH CH(g)213.8
24、213.8H2O(g)fGol1130.6130.6m(298.15K)/kJm228.57228.57解:(1)rGBfG)m(298.15K)m(B,298.15KB 213.8228.57130.6 145.4kJmol1 0由由rGm RTlnK得得lnK rGm/RT145.4103/(8.314298.15)58.6525K 2.9810BfG)(2)rGm(298.15K)m(B,298.15KB 213.8130.683.2kJmol1 0lnK rGm/RT 83.2103/(8.314298.15)33.56K 2.651015所以反应(1)可行。27.已知反应2SO2(g
25、)+O2(g)2SO3(g)在 427和 527时的 K值分别为 1.0105和1.1102,求该温度范围内反应的rHm。解:lnK1 H 11 rmK2RT1T2rHm1.010511ln 231.1108.31410427 273.15527 273.15rHm=317 kJmol128.计算密闭容器中反应 CO(g)+H2O(g)CO2+H2(g)在 800K 时的平衡常数K;若欲使此时 CO 的转化率 90%,则原料气的摩尔比n(CO):n(H2O)应为多少?解:rGmBfHm1573BSm 393.509(110.525 241.818)800(213.74130.684188.82
26、5197.674)103 7.506kJ/molrGm RT lnK7.506 8.314103800lnKK 3.09假设是 CO 的转化率为 90%,假设nco2nH2oaCO+H2O=CO2+H21a0.90.90.90.9平衡0.1a-0.90.90.90.92Ka=3.520.1(a 0.9)nco2nH2o7N2(g)+3H2(g),在 673 K 和 100 kPa 总压下的解离度为29.NH3的分解反应为 2NH3(g)98%,求该温度下反应的平衡常数K和rGm。解:2NH3(g)N2(g)+3H2(g)100平衡(1-a)1/2a3/2a11/23/2;p(N2)p总;p(H
27、2)p总111pNpH2()(2)3(0.49)(1.47)3pp1.98 992.6=1.98K0.022pNH23()()1.98pp(NH3)p总rGm RT ln K 8.314673ln992.6 3.861104J/mol 38.61kJ/mol30.Write equations for the two reactions corresponding to the followingfHmvalues.Combine theseequations to give that for the reaction.2NO2(g)N2O4(g)Caculate therHmvalue fo
28、r this reaction,and state whether the reaction is endothemic or exothermic.fHm(NO2,g)33.84kJ/molfHm(N2O4,g)9.66kJ/molSolution:1/2N2(g)+O2(g)N2(g)+2O2(g)NO2(g),fHm(NO2,g)33.84kJ/molN2O4(g),fHm(N2O4,g)9.66kJ/molrHmBfHm 9.662(33.84)58.02kJ/mol,The reaction is exothermic.31.The enthalpy change for which
29、 of the following process represents the enthalpy of formation of AgCl?Explain.(a)Ag(aq)Cl AgCl(s)(b)Ag(s)1Cl(g)AgCl(s)22(c)AgCl Ag(s)1Cl(g)(d)Ag(s)AuCl(s)AgCl(s)Au(s)22Solution:(b)32.Under standard state,caculate the enthalpy of decompsition of NaHCO3(s)into Na2CO3(s),CO2(g)and H2O(g)at 298.15K.2Na
30、HCO3(s)Na2CO3(s)+CO2(g)+H2O(g)Solution:rHmBfHm(1130.68)(393.51)(241.82)2(950.81)33.91Jmol133.Without consulting entropy tables,predict the sign ofS for each the following process.(a)O2(g)2O(g)(b)N2(g)3H2(g)2NH3(g)(c)C(s)H2O(g)CO(g)H2O(g)(d)Br2(l)Br2(g)(e)Desaltination of seawater(f)Hard boiling of a
31、n egg.Solution:(a)S0(b)S0(c)S0(d)S0(e)S0(f)S0for the formation of HI(g)from its gaseous elements is-10.10 kJ/mol at 500K.When the partial34.fGmpressure of HI is 10.0 atm,and of I2 0.001 atm,what must the partial pressure of hydrogen be at this temperatureot reduce the magnitude ofGfor the reaction t
32、o 0.Solution:I2(g)+H2(g)G rGm RT lnQ2HI(g)0 10.102 8.314500lnQ102=129Q 0.001 pH2pH2 775.2atm35.Calculate the enthalpy change for the reactionsSiO2(s)4HF(g)SiF4(g)2H2O(g)SiO2(s)4HCl(g)SiCl4(g)2H2O(g)Explain why hydrofluoric acid attacks glass,whereas hydrochloric acid does dot.Solution:反应(1)rHmBfHm(1
33、614.9)(241.82)(910.49)(271.1)反应(2)rHm 675.11Jmol1BfHm(657.01)(241.82)(910.49)(92.31)103.99Jmol1反应(1)是放热反应,而反应(2)是吸热反应,所以(1)更容易进行。36.In a catalytic experiment involving the Haber process,mesured asN23H2 2NH3,the rate of reaction wasv(NH3)NH3 2.0104molL1s1tIf there were no side reactions,what was the
34、rate of reaction expressed in terms of(a)N2(b)H2?Solution:123(H2)2.0104 3.0104mol L1s12(N2)2.01041.0104molL1s137.In terms of reaction kinetics,explain why each of the following speeds up a chemical reaction:(a a)catalyst(b b)increase in temperature(c c)increase in concentration.Solution:(a a)由于催化剂降低
35、了化学反应的活化能,加快了化学反应的进行。(b b)温度升高,参与反应的分子的平均能量升高,从而降低了活化能;另外,温度升高,同时分子碰撞频率增快,所以加快了化学反应。(c c)浓度升高,活化分子数目增多,所以化学反应加快。38.What is the rate law for the single-step reaction A+B 2C?A possible mechanism for the reaction2H2 2NO N2 2H2Ois2NON2O2H2 N2O2 N2O H2OH2 N2O N2 2H2OIf the second step is rate determining
36、,what is the rate law for this reaction?Solution:k CACB k C2NO39.Calculatethevalueofthethermodynamicdecompositiontemperature(Td)react ionNH4Cl(s).=NH3(g)+HCl(g)at th e st andard state.Solution:rHm=46.11 92.307+314.43 kJmol1=176.01 kJmol1rSm=192.45+186.90894.6 Jmol1K1=284.758Jmol1K1Td=rHm/rSm=176.01 kJmol1/284.758103kJmol1K1=618.12K40.The rate constant for the reaction of oxygen atomswith aromatic hydrocarbons was 3.03 107 Lmol-1s-1 at341.2K,and 6.91107 Lmol-1s-1 at 392.2K.Calculate the activation energy of this reaction.Solution:6.91107Ea11lg()72.3038.314 392.2341.23.0310Ea 17.9kJ/mol