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Chap 5 chemical bonding

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Text of Chap 5 chemical bonding

  • 1

    5

    (Chemical Bonding)

    5-1

  • 5-2

  • 1. (ionic bond)2. (covalent bond)3. (coordinate

    covalent bond)4. (metallic bond)

    5-3

  • 1. (hydrogen bond)2. (Van de Waals forces)3. -

    (molecule - ion attractions)

    5-4

  • (Octet Rule)

    5-5

  • (cation) (anion)

    5-6

    (Ionic Bond)

  • 7

    : e-

    1123 Na

    -1e-

    Na+ p > e- 1

    : e- : 2 8

    Mg(2 8 2) -2e-

    Mg2+(2 8)

    p > e-

    : e- : 2 8 1

    5-7

  • 8

    : e-

    1735Cl ( 2 8 7)+1e- Cl- (2 8 8)

    e- > p 1

    816O (2 6)+2e-

    O2- (2 8)

    e- > p

    5-8

  • 9

    Chlorine Cl2-8-7

    Sodium Na2-8-1

    17+11+

    5-9

  • :

    :

    5-10

    (ionic compound)

  • 1. : 2.

    CCZr

    COMg

    CClNa

    o44

    o22

    o

    3500 = mp.

    2640 = mp.

    801 = mp.

    5-11

    (Ionic compound)

  • 3. 3

    rock salt (NaCl-st)6 : 6

    Cl- Na+

    Na+ Cl-

    Na+ Cl- Na+ Cl-

    Cl- Na+ Cl- Na+

    Na+ Cl- Na+ Cl-

    Na+Cl--st...

    5-12

  • Cs+Cl- -st. = 8 : 8 :

    5. / ......................................................................6. .............................................

    d-

    H Hd+

    NaCl Na+(aq)+ Cl-(aq)H2O

    d+

    4.

    --->

    5-13

  • +

    ++

    ++

    +

    ++ +

    +++

    -

    -

    -

    --

    -

    -

    --

    --

    -

    NaCl

    5-14

  • : e- 2 8 ( 2 H)

    Cl2 Cl + Cl Cl - ClO2 O + O O = OHCl H + Cl H - ClS + S + S -S-S-S-

    long chains

    H2 H + H H - H

    -dd+

    5-15

    (Covalent Bond)

  • : 8-N Rule8-N N = e- N 8-N Cl 7 1 , Cl2S,Se,Te 6 2 , long chainAs, Sb, Bi 5 3 , sheets of atomsC 4 4 3 ,

    net work5-16

  • N < 4 C (, mp = 3500oC) 3 : 3

    5-17

  • electronegativity (EN) (polar covalent bond polar bond) HCl

    5-18

  • (non - polar covalent bond) EN H2, N2, O2

    5-19

  • HCl, HF, HBr

    5-20

  • () CO2 (

    ) H2O, NH3

    5-21

  • (Coordinate Covalent Bond)

    NH3 + H+ NH4+

    5-22

  • (Metallic Bond)1. free - electron theory (e- sea model)2. (bond theory):

    : (Metallic crystal) : e- e- (ionized)

    5-23

  • : & mp & bp ( )

    : e- e-

    :

    5-24

  • +

    + + + + + + ++ + + + + + +

    ++ + + + +

    + + + + + + +

    : e- Fe 1, 2 2 ( Be, Mg) 1 ( Na, Li)

    5-25

  • 1. e-

    2. ........................................ e- ()

    5-26

  • 3. (high reflectivity) e- e-

    4. ...................................

    e-

    5-27

  • Na+ Na+ Na+

    e- e- e-

    Na+ Na+ Na+

    e- e- e-

    Na+ Na+ Na+

    e- e- e-

    5. (alloys) e-

    5-28

  • 2. (Band theory) : 2 (AMO) (BMO) 2

    5-29

  • MO MO (energy band) Li 2s orbital 2s

    5-30

  • 31

    (allowed band) (forbidden gap)

    5-31

  • 1. (Valence Bond Theory, VB )2. (Molecular Orbital

    Theory, MO)

    5-32

  • 33

    5-33

    (Valence Bond Theory)

  • ro ()

    5-34

  • > > < <

    5-35

  • 1 1 1 1 2

    5-36

  • 5-37

  • 5-38

    F2 (1s2 2s2 2p5)

    2pz

  • (Hybridization)

    (hybrid orbital) -

    5-39

  • C62p

    2s

    e- 2p 2 2 4 s p

    5-40

  • 41

    C62p

    2ssp3

    (s2p2) sp3

    s 1 p 3 sp3

    5-41

  • 1. sp - s p

    5-42

  • sp - BeCl2, C2H2BeCl2

    Be Cl Cl BeCl2 5-43

  • 5-44

    BeCl2

    C2H2

  • C2H2 ; 2s 2p sp - H p -

    5-45

  • 2. sp2- s 1 p 2

    5-46

  • sp2 - C2H4, BF3BF3

    B s 1 p 2 sp2- F

    5-47

  • C2H4

    C2H4 ; 2s p sp2- H p -

    5-48

  • 3. sp3 - s 1 p 3

    5-49

  • 5-50

    sp3 - CH4

    2s 2p C sp3 - H

  • 4. sp3d - s 1 , d 1 p 3 (trigonal bipyramid)

    5-51

  • 5-52

    sp3d - PCl5

    3s, 3p 3d P sp3d - - Cl

  • 5. sp3d2 - s 1 , d 2 p 3 (octahedral)

    5-53

  • sp3d2 - SF6

    5-54

    3s, 3p 3d S sp3d2 - - F

  • 1.

    , n 1 2 3 4

    e- , 2n2 2 8 18 32

    1s 2s 2p 3s 3p 3d 4s 4p 4d 4f

    e-

    2 2 6 2 6 10 2 6 10 14

    1s2 2s2 2p6 3s2 3p6 3d10 4s2 4p6 4d10 4f14

    1 1 3 1 3 5 1 3 5 7

    5-55

  • 56

    s p

    s orbital

    p orbital

    5-56

  • 2. 2 1. (bonding molecular orbital ; BMO) 2. (anti - bonding molecular orbital ; AMO)

    5-57

  • 5-58

    BMO AMO - s (s - orbital)

    - p (p - orbital)

  • 5-59

    .

    .

  • - p.-p

    ( -bond) .-p (p-bond)

    (* ) BMO AMO -s s *s BMO AMO -p z, *z, px, p*x , py , p*y pz px, py

    5-60

  • 1s < *1s < 2s < *2s < py, px < z < p*y , p*x < *z

    O2 F2 2z < 2pPx < 2pPy

    5-61

  • AO = MO = (homonuclear diatomic molecule)

    5-62

    . (homonuclear diatomic molecule)

    O2, F2

  • 1. 2.

    2.1 2 2.2

    3. px py

    5-63

  • H 1 2H 2 () H2 H

    5-64

  • = 1/2 ( - )

    H2 = 1/2(2-0) = 1

    5-65

  • (paramagnetic)

    (diamagnetic)

    5-66

  • ( )

    5-67

  • 5-68

  • . (heteronuclear diatomicmolecule) HFHF : H 1 F 7 8 4 H non - bonding orbital

    5-69

  • 5-70

  • Valence Shell Electron Pair Repulsion Theory(VSEPR Theory)

    5-71

  • AXmEn

    A = X = A E = m = n =

    5-72

  • AXmEn SF4 ICl4-

    SF4 ICl4- 6 7 4 4 - 1 10(5) 12(6) 4 4 1 2 AXmEn AX4E1 AX4E2

    FSF4 S..

    FFF

    ICl4- ICl ClClCl....

    5-73

  • VSEPR1. m n 2. - > - > -3. multiple bond 4.

    > >>

    5-74

  • 1. AX2 (linear) : BeCl2

    Cl Be Cl

    2

    180o

    5-75

  • 3. AX4 (tetrahedral) : CH4

    4

    C

    H

    HH

    H

    109.5o

    2. AX3 (triangular planar) : BF3

    B

    F

    FF

    120o

    5-76

  • 5. AX6 (octahedral) : SF6

    90o

    S

    F

    F

    FF

    F

    F

    4. AX5 (trigonal bipyramidal) : PCl5

    3 (axial) 3 3 (equatorial)

    P

    Cl

    Cl

    ClCl

    Cl

    90o

    120o

    5-77

  • :- > - > -

    1. AX2E (V-shaped) : SO2

    OSO 120o 119.5o

    O S O.. ....

    .. ..

    ..

    ....

    ....

    S

    O O

    5-78

  • 2. AX3E (trigonal pyramidal) : NH3

    N-H 3

    3. AX2E2 (V-shaped) : H2O

    4 4 2 O-H N-H

    N HH

    H

    ..

    H O H....

    ..

    O

    H H

    ..

    NHH

    H..

    5-79

  • 4. AX4E (square pyramidal or distorted tetrahedral) : SF4

    SF

    F

    F

    F

    .. S..

    F

    FF

    F

    120o

    5-80

  • 5-81

    = = =

  • 1 (CH3OH)

    CO

    H

    H

    HH

    TetrahedralBent

    5-82

  • 5-83

  • 5-84

  • 1.

    - ( e- )- e-

    AB B

    I

    IIIII

    A EN B III > I

    A EN B III < I

    AB B

    AB B 5-85

  • F O N Cl Br I S C H P EN 4.0 3.5 3.0 3.2 2.8 2.5 2.5 2.5 2.1 2.1

    EN Cl > N Cl > N EN N > Cl

    EN

    ?

    SbH3 PH3 NH3 AsH35-86

  • 2. - ( )

    - ( )

    EN (EN)

    H HEN 2.1 2.1

    EN = 0

    2.1

    5-87

  • 2.2

    H ClEN 2.1 3.2

    EN = 1.1

    2.3

    C OEN 3.5 2.5 3.5

    O2+1- 1-

    5-88

  • CC

    H

    H

    Cl

    ClEN 2.1 2.5 3.2

    2.4

    OH H

    EN 2.1 3.5 2.1

    5-89

  • 3.

    ()

    C - C

    (pm) (kJ mol-1)

    H3C-CH3 C-C 154 348 H2C=CH2 C=C 134 614 HCCH CC 120 839

    5-90

  • (hydrogen bond) EN ............

    5-91

  • (H2O), HF

    H Fd d H Fd d HF,

    Hd

    Hd

    Hd

    HdHd

    Hd

    d

    dd

    5-92

  • (Van der Waals forces)

    5-93

    3 1. - (dipole - dipole interaction)2. (induced attraction)3. (London force or

    disperse attraction)

  • : dipole - dipole interaction

    H Cl Cl H Cld d d d d d

    ......... ......... H

    :

    5-94

  • (induced attraction)

    5-95

  • (London force)

    5-96

  • : e- ( e- ) dynamic dipole 2

    :

    ?

    5-97

  • (weak electrostatic