高中化学选修三第二章分子结构与性质一、共价键1.共价键的本质及特征共价键的本质是在原子之间形成共用电子对，其特征是具有饱和性和方向性。2.共价键的类型①按成键原子间共用电子对的数目分为单键、双键、三键。②按共用电子对是否偏移分为极性键、非极性键。③按原子轨道的重叠方式分为σ键和π键，前者的电子云具有轴对称性，后者的电子云具有镜像对称性。3.键参数①键能：气态基态原子形成1mol化学键释放的最低能量，键能越大，化学键越稳定。②键长：形成共价键的两个原子之间的核间距，键长越短，共价键越稳定。③键角：在原子数超过2的分子中，两个共价键之间的夹角。④键参数对分子性质的影响：键长越短，键能越大，分子越稳定。4.等电子原理原子总数相同、价电子总数相同的分子具有相似的化学键特征，它们的许多性质相近。二、分子的空间构型1．分子构型与杂化轨道理论杂化轨道的要点：当原子成键时，原子的价电子轨道相互混杂，形成与原轨道数相等且能量相同的杂化轨道。杂化轨道数不同，轨道间的夹角不同，形成分子的空间形状不同。分子构型杂化轨道理论杂化类型杂化轨道数目杂化轨道间夹角空间构型实例sp2180°直线型BeCl2sp23120°平面三角形BF3sp34109°28’正四面体形CH42．分子构型与价层电子对互斥模型价层电子对互斥模型说明的是价层电子对的空间构型，而分子的空间构型指的是成键电(1)(2)220BeCl2330BF3321VSnBr2440CH4431NH3422VH2O3.1()H-HH-ClH2H2O2Na2O2HClNaOHNH4Cl2()()[Ag(NH3)2]OHAgNH321>>A-HB-ABB2(1)(2)3(1)(2)45(HO)mROnRnRR-O-HORHHClOHClO2HClO3HClO41.A.B.C.D.B2.A.H[OO]2HB.H[F]C.NHHHD.HO,HD3.A.B.C.D.ANNBCDC4.A.pB.C.D.H2Cl2C5.HClH2ON2H2O2C2H4C2H2A.B.C.D.D6.A.B.C.D.B7.A.B.C.D.N2946kJmol1O2497.3kJmol1D8.2011NNO23NN108.1NNO23A.NOB.C.D.15.2g6.021022ANOABNN108.1BCN0NO2N4CD15.2g0.1mol106.021023C9.A.SO2O3B.CO2NO2C.CS2NO2D.PCl3BF3B3C4NP5OS6FCl7A10.kJmol1HBrBrIClClHClHHBr436.0193.7152.7242.7431.8298.7366121molH22molCl2kJ31molH2Cl2Br2I2A.Cl2Br2I2B.Br2Cl2I2C.Br2I2Cl241molH2F2Cl2HH2gCl2g===2HClgH436.0kJmol1242.7kJmol12431.8kJmol1184.9kJmol1H2gBr2g===2HBrgH436.0kJmol1193.7kJmol12366kJmol1102.3kJmol1H2gI2g===2HIgH436.0kJmol1152.7kJmol12298.7kJmol18.7kJmol1F2Cl2Br2I2H21H2184.93A411.20ABCDEF6BACBDACBD12CDEEpDp6FA1CE__________________________2F_____________________________3A2D4ABCBBBDDBD241212ACACBD12ACCDEEpDpE6FAF121s22s22p63s23p64s13HSH412.1molkJCl2Br2I2HClHBrHIH2kJ243193151431366298436151A.H2B.Cl2C.Br2D.I22A.HClB.HBrC.HI3X2H2===2HXXClBrI________________________________________________________________4X2XClBrI54__________________________________________________________________1mol1mol11molH2436kJ21molHClH23183kJ103kJ9kJ1A2A34Cl251.A.CH4B.NH3C.H2OD.C2H4VA2.110ABCDNH3HCNCONH22BF33.SO3A.B.VC.D.SO3S1263203DD4.A.PCl3B.H3OC.HCHOD.PH3PCl3P31H3OPH331HCHO3C5.A.sp2sp2B.sp3sp3C.sp2sp3D.spsp33sp24sp3C6.SO42SA.spB.sp2C.sp3D.SO42S04sp3CH4C7.AgNO3AgClA.[CoNH34Cl2]ClB.[CoNH33Cl3]C.[CoNH36]Cl3D.[CoNH35Cl]Cl2ClAgNO3AgClB[CoNH33Cl3]Co3NH3ClClAgClB8.H3O[B(OH)4]CH3COONH3CH4A.B.C.D.H3OHH2OO[BOH4]3OHB31OHOBA9.1_______________________________________________________________23CC120_______________________________1sp22C===O3CCC1201sp223C10.ClOClO2ClO3ClO4Clsp3OClOClO2ClO3ClO4ClO3sp3H2ONH3CH4NH4V11.ABCDEYXZXYZYABCDEBDCEAE1AB________________________________________________________2_________________________________3Cl2AB__________________________YABCDEBAYCDEDCEAEABCDENH3N2NONO2HNO3123NO2H2O===2HNO3NO38NH33Cl2===N26NH4Cl12.1CuBCu22[CuNH34]2NF3NH3NF3Cu2_____________________________________________________________1Cu[Ar]3d104s1Cu24s3dCu2[Ar]3d91s22s22p63s23p63d92NFHFNHNH3NNF3FN1[Ar]3d91s22s22p63s23p...
