7 7.1 Chapter 7 Covalent Bonding

7 7.1 Chapter 7 Covalent Bonding

7 7.2? Lewis : Lewis

7 7.3 (valance electron) # of valance e- = # of group (core electron) (Bond) (ionic bond) : metal-nonmetal (covalent bond) : nonmetal-nonmetal (metallic bond) : metal-metal

7 7.4 7.1 Lewis Lewis,, ( ). (dot ) H + F H F 2H + O H O H H 2 O HF H 8 (octet).. : Octect Rule

7 7.5 Lewis Step 1. Step 2. Step 3. Step 4. Step 5.

7 7.6 Step 1. Central atom : F Terminal atom : H, O, Halogen

Step 2. (valence electrons) = =( ) H # of valance e - = 1,. OCl - ion: 6 + 7 + 1 = 14 valence e - CH 3 OH molecule: 4 + 4(1) + 6 = 14 valence e - SO 3 2- ion: 6 + 3(6) + 2 = 26 valence e - 7 7.7

7 7.8 Step 3. 1 (= ) 4 H O Cl H C O H O S O H O

7 7.9 Step 4. : OCl - ion: 14-2 = 12 valence e - left CH 3 OH molecule: 14-10 = 4 valence e - left SO 2-3 ion: 26-6 = 20 valence e - left : Terminal atom (Octect rule), : H ( O Cl ) - H C O H ( O S O ) 2- H O

7 7.10 Step 5. Octect Rule Terminal atom C, N, O, P, S

7 7.11 1) NO - 3 S1. O N O O S2. # valence e - = 5 + 18 + 1 = 24 S3. O N O O S4. # of valence e - left: 24-6 = 18

7 7.12 S4. Terminal atom O N O N 6. 2 : O N O N 2? 10 valence e - N N O O

2) CH 4 7 7.13

3) PF 3 7 7.14

4) CO 2 7 7.15

5) CH 3 CO - 2 7 7.16

7 7.17 1) 8 : F Be F F B F F

7 7.18 2) (expanded octet) : ) XeF 4 : 36 valence e -. octet structure 32, 4, 12 F F Xe F F

7 7.19 (Resonance Forms) (delocalization) : Stabilization NO 3-3 : O = N O O N O O N = O O O 3 ( hybrid). octet rule Lewis. O :

7 7.20 7.2 (Molecular Geometry) VESPR : Valance Shell Electron Pair Repulsion. P-block 2 6, : BeF linear 2 BeF 3 triangular planar CF 4 tetrahedral PF 5 triangular bipyramid SF 6 octahedral

7 7.21

7 7.22 AX 2 (linear) 180 BeF 2 AX 3 (Tiangular) 120 BF 3 AX 4 AX 5 (Tetrahedral) 109.5 CH 4 90,120, PF 5 (Trigonal bipyramid) 180 AX 6 (Octahedral) 90, 180 SF 6

7 7.23 (lone pair electron) (lone pair elctron): AX 2 E (GeF 2 ) :bent, 120 AX 3 E (NH 3 ) :triangular pyramid, 109 AX 2 E 2 (H 2 O) :bent, 109

7 7.24 5 ELECTRON PAIRS

7 7.25 5 ELECTRON PAIRS

7 7.26

7 7.27 : BF 3 and SO 3 : both AX 3, same geometry BeF 2 and CO 2 : both AX 2, both linear F Be F O=C=O 180 180 H C C H

7 7.28 (molecular Shape) 1. Lewis 2. ( + ) 3. VSEPR 4. (lone pair electron)

7 7.29 7.3 (Polarity)

7 7.30, H H E.N. = 0 H C E.N. = 0.3 H F E.N. = 1.8 (- pole at F atom)

7 7.31 : HCl,Cl 2 H Cl Cl Cl polar nonpolar : O F Be F CH 4 CH 3 Cl H H nonpolar polar nonpolar polar

7 7.32 7.4 ; (Hybridization) Bonding Model Valance Bond Theory Molecular Orbital Theory MOT( ) s p. s, p, d ( hybrid orbitals ).

CH 4 :sp 3 7 7.33

7 7.34 s + p 2 sp 2s 2p Be in BeF 2 ( ) ( )( )( ) s + 2 p 3 sp 2 2s 2p B in BF 3 ( ) ( )( )( ) s + 3 p 4 sp 3 2s 2p C in CH 4 ( ) ( ) ( ) ( )

sp 7 7.35

7 7.36 5 6 ( ) sp 3 d, sp 3 d 2 2 (e.g.. N, O, F) 2d.

7 7.37 (Unshared Pairs) (H 2 O, NH 3 ). O S = O sp 2 hybridization for sulfur O = C = O sp hybridization for carbon

7 7.38 ( ) ( ) bond :,.. bond : (extra),, (lobe)..

7 7.39 CH 4

7 7.40

7 7.41 ( ) CO 2 2 sigma bonds; 2 pi bonds SO 2 2 sigma bonds; 1 pi bond N 2 1 sigma bond; 2 pi bonds