1、1(2017江苏高考)通过以下反应可获得新型能源二甲醚(CH3OCH3)。下列说法不正确的是()C(s)H2O(g)=CO(g)H2(g)H1a kJmol1CO(g)H2O(g)=CO2(g)H2(g)H2b kJmol1CO2(g)3H2(g)=CH3OH(g)H2O(g)H3c kJmol12CH3OH(g)=CH3OCH3(g)H2O(g)H4d kJmol1A反应、为反应提供原料气B反应也是CO2资源化利用的方法之一C反应CH3OH(g)=CH3OCH3(g)H2O(l)的H kJmol1D反应2CO(g)4H2(g)=CH3OCH3(g)H2O(g)的H(2b2cd) kJmol1
2、答案C解析A对:反应的反应物是反应、的产物,所以反应、为反应提供原料气。B对:反应是CO2与H2反应制取甲醇,是CO2资源化利用的方法之一。C错:该反应产物H2O为气态时,H kJmol1。D对:根据盖斯定律,反应22可得反应2CO(g)4H2(g)=CH3OCH3(g)H2O(g)的H(2b2cd) kJmol1。2(2016江苏高考)通过以下反应均可获取H2。下列有关说法正确的是()太阳光催化分解水制氢:2H2O(l)=2H2(g)O2(g)H1571.6 kJmol1焦炭与水反应制氢:C(s)H2O(g)=CO(g)H2(g)H2131.3 kJmol1甲烷与水反应制氢:CH4(g)H2
3、O(g)=CO(g)3H2(g)H3206.1 kJmol1A反应中电能转化为化学能B反应为放热反应C反应使用催化剂,H3减小D反应CH4(g)=C(s)2H2(g)的H74.8 kJmol1答案D解析A项,反应是光能转化为化学能,错误;B项,反应的焓变为正值,属于吸热反应,错误;C项,催化剂不会改变反应的焓变,错误;D项,根据盖斯定律,得所求反应,其焓变为:206.1 kJmol1131.3 kJmol174.8 kJmol1,正确。3(2015上海高考)已知H2O2在催化剂作用下分解速率加快,其能量随反应进程的变化如图所示。下列说法正确的是()A加入催化剂,减小了反应的热效应B加入催化剂,
4、可提高H2O2的平衡转化率CH2O2分解的热化学方程式:H2O2H2OO2QD反应物的总能量高于生成物的总能量答案D解析A项,加入催化剂,对反应的热效应无影响,错误;B项,加入催化剂,只能改变反应速率,不能使平衡移动,故无法提高H2O2的平衡转化率,错误;C项,热化学方程式需标明物质的状态,错误;D项,由图像知,该反应的反应物的总能量高于生成物的总能量,正确。 4(2015重庆高考)黑火药是中国古代的四大发明之一,其爆炸的热化学方程式为:S(s)2KNO3(s)3C(s)=K2S(s)N2(g)3CO2(g)Hx kJmol1已知:碳的燃烧热H1a kJmol1S(s)2K(s)=K2S(s)
5、 H2b kJmol12K(s)N2(g)3O2(g)=2KNO3(s)H3c kJmol1则x为()A3abc Bc3abCabc Dcab答案A解析C(s)O2(g)=CO2(g)H1a kJmol1;S(s)2K(s)=K2S(s)H2b kJmol1;2K(s)N2(g)3O2(g)=2KNO3(s)H3c kJmol1。根据盖斯定律:3可得:S(s)2KNO3(s)3C(s)=K2S(s)N2(g)3CO2(g)H(3abc) kJmol1,故x3abc,选项A正确。5(2018高考组合题)(1)(全国卷)已知:2N2O5(g)=2N2O4(g)O2(g)H14.4 kJmol12N
6、O2(g)=N2O4(g)H255.3 kJmol1则反应N2O5(g)=2NO2(g)O2(g)的H_kJmol1。(2)(全国卷)CH4CO2催化重整反应为:CH4(g)CO2(g)=2CO(g)2H2(g)。已知:C(s)2H2(g)=CH4(g)H75 kJmol1C(s)O2(g)=CO2(g)H394 kJmol1C(s)O2(g)=CO(g)H111 kJmol1该催化重整反应的H_kJmol1。(3)(全国卷)SiHCl3在催化剂作用下发生反应:2SiHCl3(g)=SiH2Cl2(g)SiCl4(g)H148 kJmol13SiH2Cl2(g)=SiH4(g)2SiHCl3(
7、g)H230 kJmol1则反应4SiHCl3(g)=SiH4(g)3SiCl4(g)的H_kJmol1。(4)(北京高考)反应:2H2SO4(l)=2SO2(g)2H2O(g)O2(g)H1551 kJmol1反应:S(s)O2(g)=SO2(g)H3297 kJmol1 (5)(天津高考)CO2与CH4经催化重整,制得合成气:CH4(g)CO2(g)2CO(g)2H2(g)已知上述反应中相关的化学键键能数据如下:则该反应的H_。(6)(江苏高考)用水吸收NOx的相关热化学方程式如下:2NO2(g)H2O(l)=HNO3(aq)HNO2(aq)H116.1 kJmol13HNO2(aq)=H
8、NO3(aq)2NO(g)H2O(l)H75.9 kJmol1反应3NO2(g)H2O(l)=2HNO3(aq)NO(g)的H_kJmol1。答案(1)53.1(2)247(3)114(4)3SO2(g)2H2O(g)=2H2SO4(l)S(s)H2254 kJmol1(5)120 kJmol1(6)136.2解析(1)已知:.2N2O5(g)=2N2O4(g)O2(g)H14.4 kJmol1.2NO2(g)=N2O4(g)H255.3 kJmol1根据盖斯定律可知2即得到N2O5(g)=2NO2(g)O2(g)HH253.1 kJmol1。(2)已知:C(s)2H2(g)=CH4(g)H7
9、5 kJmol1C(s)O2(g)=CO2(g)H394 kJmol1C(s)O2(g)=CO(g)H111 kJmol1根据盖斯定律可知2即得到CH4CO2催化重整反应CH4(g)CO2(g)=2CO(g)2H2(g)的H247 kJmol1。(3)将第一个方程式扩大3倍,再与第二个方程式相加就可以得到目标反应的焓变,所以焓变为483(30) kJmol1114 kJmol1。(4)根据过程,反应为SO2催化歧化生成H2SO4和S,反应为3SO22H2O=2H2SO4S。应用盖斯定律,反应反应得,2H2SO4(l)S(s)=3SO2(g)2H2O(g)HH1H3(551 kJmol1)(29
10、7 kJmol1)254 kJmol1,反应的热化学方程式为3SO2(g)2H2O(g)=2H2SO4(l)S(s)H254 kJmol1。(5)化学反应的焓变应该等于反应物键能减去生成物的键能,所以焓变为(44132745) kJmol1(210752436) kJmol1120 kJmol1。(6)将两个热化学方程式编号,2NO2(g)H2O(l)=HNO3(aq)HNO2(aq)H116.1 kJmol1(式)3HNO2(aq)=HNO3(aq)2NO(g)H2O(l)H75.9 kJmol1(式)应用盖斯定律,将(式3式)2得,反应3NO2(g)H2O(l)=2HNO3(aq)NO(g
11、)H(116.1 kJmol1)375.9 kJmol12136.2 kJmol1。6(2017高考组合题)(1)(全国卷)下图是通过热化学循环在较低温度下由水或硫化氢分解制备氢气的反应系统原理。通过计算,可知系统()和系统()制氢的热化学方程式分别为_、_,制得等量H2所需能量较少的是_。(2)(全国卷)丁烯是一种重要的化工原料,可由丁烷催化脱氢制备。回答下列问题:正丁烷(C4H10)脱氢制1丁烯(C4H8)的热化学方程式如下:C4H10(g)=C4H8(g)H2(g) H1已知:C4H10(g)O2(g)=C4H8(g)H2O(g)H2119 kJmol1H2(g)O2(g)=H2O(g)
12、H3242 kJmol1反应的H1_kJmol1。(3)(北京高考)TiCl4是由钛精矿(主要成分为TiO2)制备钛(Ti)的重要中间产物,制备纯TiCl4的流程示意图如下:氯化过程:TiO2与Cl2难以直接反应,加碳生成CO和CO2可使反应得以进行。已知:TiO2(s)2Cl2(g)=TiCl4(g)O2(g)H1175.4 kJmol12C(s)O2(g)=2CO(g)H2220.9 kJmol1沸腾炉中加碳氯化生成TiCl4(g)和CO(g)的热化学方程式:_。答案(1)H2O(l)=H2(g)O2(g)H286 kJmol1H2S(g)=H2(g)S(s)H20 kJmol1系统()(
13、2)123(3)TiO2(s)2Cl2(g)2C(s)=TiCl4(g)2CO(g)H45.5 kJmol1解析(1)令题干中的四个热化学方程式分别为:H2SO4(aq)=SO2(g)H2O(l)O2(g)H1327 kJmol1SO2(g)I2(s)2H2O(l)=2HI(aq)H2SO4(aq)H2151 kJmol12HI(aq)=H2(g)I2(s)H3110 kJmol1H2S(g)H2SO4(aq)=S(s)SO2(g)2H2O(l)H461 kJmol1根据盖斯定律,将可得,系统()中的热化学方程式:H2O(l)=H2(g)O2(g)HH1H2H3327 kJmol1151 kJ
14、mol1110 kJmol1286 kJmol1同理,将可得,系统()中的热化学方程式:H2S(g)=H2(g)S(s)HH2H3H4151 kJmol1110 kJmol161 kJmol120 kJmol1由所得两热化学方程式可知,制得等量H2所需能量较少的是系统()。(2)由盖斯定律可知,式式式,即H1H2H3119 kJmol1(242 kJmol1)123 kJmol1。(3)钛精矿的主要成分是TiO2,在沸腾炉中加碳氯化时生成TiCl4(g)和CO(g)的反应为TiO2(s)2Cl2(g)2C(s)TiCl4(g)2CO(g)。将题给两个已知热化学方程式依次编号为、,根据盖斯定律,
15、由可得TiO2(s)2C(s)2Cl2(g)=TiCl4(g)2CO(g),则有H(175.4 kJmol1)(220.9 kJmol1)45.5 kJmol1。7(2016高考组合题)(1)(全国卷)已知2O2(g)N2(g)=N2O4(l)H1N2(g)2H2(g)=N2H4(l)H2O2(g)2H2(g)=2H2O(g)H32N2H4(l)N2O4(l)=3N2(g)4H2O(g)H41048.9 kJmol1上述反应热效应之间的关系式为H4_。(2)(四川高考)工业上常用磷精矿Ca5(PO4)3F和硫酸反应制备磷酸。已知25 ,101 kPa时:CaO(s)H2SO4(l)=CaSO4
16、(s)H2O(l)H271 kJmol15CaO(s)3H3PO4(l)HF(g)=Ca5(PO4)3F(s)5H2O(l)H937 kJmol1则Ca5(PO4)3F和硫酸反应生成磷酸的热化学方程式是_。答案(1)2H32H2H1(2)Ca5(PO4)3F(s)5H2SO4(l)=5CaSO4(s)3H3PO4(l)HF(g)H418 kJmol1解析(1)由已知热化学方程式可得:N2O4(l)=2O2(g)N2(g)H12N2H4(l)=2N2(g)4H2(g)2H22O2(g)4H2(g)=4H2O(g)2H3根据盖斯定律,将上述三个热化学方程式相加,可得2N2H4(l)N2O4(l)=
17、3N2(g)4H2O(g)H42H32H2H1。(2)CaO(s)H2SO4(l)=CaSO4(s)H2O(l)H271 kJmol15CaO(s)3H3PO4(l)HF(g)=Ca5(PO4)3F(s)5H2O(l)H937 kJmol1根据盖斯定律,由5得,Ca5(PO4)3F(s)5H2SO4(l)=5CaSO4(s)3H3PO4(l)HF(g)H2715 kJmol1(937) kJmol1418 kJmol1。8(2015山东高考)贮氢合金ThNi5可催化由CO、H2合成CH4的反应。温度为T时,该反应的热化学方程式为_。已知温度为T时:CH4(g)2H2O(g)=CO2(g)4H2(g)H165 kJmol1CO(g)H2O(g)=CO2(g)H2(g) H41 kJmol1答案CO(g)3H2(g)=CH4(g)H2O(g) H206 kJmol1解析将题中两个已知的热化学方程式依次编号为、,根据盖斯定律,由可得CO(g)3H2(g)=CH4(g)H2O(g) H206 kJmol1。