From 2-D to 3-D. Chapter 9 Molecular Geometry

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1 From 2-D to 3-D Chapter 9 Molecular Geometry 1

2 Moving on to Shapes A chemical formula tells us The identity of atoms The number of atoms The Lewis structure tells us The identity of atoms The number of atoms How the atoms and electrons are arranged. The molecular geometry tells us The identity of atoms The number of atoms How the atoms and electrons are arranged The 3-d shape of that atom arrangement. 2

3 VSEPR Model Valence Shell Electron Pair Repulsion A fancy name for a simple model. A model used to sort out how the bonding and nonbonding electrons orient themselves in three dimensions In the model, pairs of electrons arrange themselves to get as far away from each other as possible in order to minimize their negative repulsions. 3

4 Vocabulary Electron Domain a region around a central atom where electrons are likely to be located. Bonding pair - a pair of electrons between two nuclei. Unshared pair (nonbonding pair, lone pair) - a pair of electrons Multiple bonds - double or triple bonds make up a single domain. Consider O 3 three domains around the central oxygen. Bonding pair Unshared pair Multiple bond 4

5 Electron Domain Geometry 2 domains Build it with a styro-ball and 2 toothpicks Linear Angle 180º 5

6 Electron Domain Geometry 3 domains Build it with styro-ball and 3 toothpicks Trigonal Planar Angles 120º 6

7 Electron Domain Geometry 4 domains Build it with styro-ball and 4 toothpicks Build it with the model kit. Find a ball with 4 holes. Stick in 4 stubby gray bonds Tetrahedral Angles 109.5º 7

8 Electron Domain Geometry 5 domains Build it with styro-ball and 4 toothpicks Build it with your model kit. Use the ball with 5 holes. Trigonal bipyramidal Angles 120º 90º 180º 8

9 Electron Domain Geometry 6 domains Build it with styro-ball and 4 toothpicks Build it with the model kit. Find the ball with 6 holes. Octahedral Angles 90º 9

10 Five Fundamental Domain Arrangements 10

11 Molecular Geometry What is the shape of the atoms? AB 2 Example: CO 2 SCN C 2 H 2 2 electron domains Linear domains 0 nonbonding domains Linear molecule Bond Angles 180º 11

12 Molecular Geometry What is the shape of the atoms? AB 3 Examples BF 3 CH 2 O NO 3 (CH 3 ) 2 CO 3 electron domains Trigonal planar 0 nonbonding domains Trigonal planar molecule Bond Angles 120º 12

13 Molecular Geometry What is the shape of the atoms? AB 2 Examples: O 3 NO 2 3 electron domains Trigonal planar 1 nonbonding domain Bent molecule Bond Angles < 120º the unshared pair takes up more space and repels the bonding domains closer together. 13

14 Ozone O 3 3 domains = trigonal planar domains 1 unshared pair = bent molecule 14

15 Molecular Geometry What is the shape of the atoms? AB 4 Examples CH 4 CF 2 H 2 4 electron domains Tetrahedral 0 nonbonding domain Tetrahedral molecule Bond Angles 109.5º 15

16 Molecular Geometry What is the shape of the atoms? AB 3 Examples NH 3 PCl 3 4 electron domains Tetrahedral 1 nonbonding domain Trigonal pyramidal molecule Bond Angles < 109.5º 16

17 Molecular Geometry What is the shape of the atoms? AB 2 Examples H 2 O CH 3 OH 4 electron domains Tetrahedral 2 nonbonding domain Bent molecule Bond Angles << 109.5º Two unshared pairs take up even more space and force the bonding domains closer together. 17

18 Bond Angles Resketch the molecular shapes of CH 4, NH 3, and H 2 O. Consider the bond angles. Unshared pairs take up more space than bonding pairs. 18

19 More on Bond Angles Sketch the Lewis structure for CCl 2 O. Consider the bond angles. Multiple bonds bulge and take up more space that single bonds. 19

20 Build a Trigonal Bipyramidal Structure Consider the five positions - different or the same? There are two different positions in this expanded octet molecule 2 Axial positions 3 Equatorial positions 20

21 Molecular Geometry What is the shape of the atoms? AB 5 Example PCl 5 5 electron domains Trigonal bipyramidal 0 nonbonding domain Name? Trigonal bipyramidal molecule Bond Angles 90º, 120º, 180º 21

22 Molecular Geometry What is the shape of the atoms? AB 4 Example SF 4 5 electron domains Trigonal bipyramidal 1 nonbonding domain Name? See saw molecule Bond Angles < 90º, < 120º, 180º 180º 22

23 Where does the unshared pair end up? Always the equatorial position The unshared pair takes up more space. Repulsion forces are minimized if the unshared pair is in the equatorial position. Only 2 (not 3) of its nearest neighbors are 90º away 23

24 Molecular Geometry What is the shape of the atoms? AB 2 Example ClF 3 5 electron domains Trigonal bipyramidal 2 nonbonding domains Name? T-shape molecule Bond Angles < 90º, 180º 180º 24

25 Molecular Geometry What is the shape of the atoms? AB 2 Examples XeF 2 I electron domains Trigonal bipyramidal 3 nonbonding domains Name? Linear molecule Bond Angles 180º 25

26 Molecular Geometry What is the shape of the atoms? AB 6 Example SF 6 6 electron domains Octahedral 0 nonbonding domain Name? Octahedral molecule Bond Angles 90º, 180º 26

27 Molecular Geometry What is the shape of the atoms? AB 5 Example BrF 5 6 electron domains Octahedral 1 nonbonding domain Name? Square pyramidal molecule Bond Angles < 90º 27

28 Molecular Geometry What is the shape of the atoms? AB 4 Example XeF 4 6 electron domains Octahedral 2 nonbonding domains Name? Square planar molecule Bond Angles 90º, 180º 28

29 2, 3, 4 domains 4-tetrahedron 3-trigonal planar 4-trigonal pyramid 3-bent (~120) 4-bent (~109.5) 2-2 atom molecules: 29

30 5, 6 domains 5-trigonal bipyramid octahedral 5-see saw square pyramid 5-T-shape square planar 5-30

31 2 12 e- r (2 atoms) toms) ble bond ond CO O 2 octahedron tetrahedron SCN 10 e- 14 e- (2 atoms) CO (2 atoms) triple bond double bond 2 F 5 0 e- l Obipyramid 2 CO 2 16 e- lf 3 O0 e- 4 ron 0 He- 4 CO ClO 2, SF 5 3, domains 16 e- XeF CH 4 2 O SO 2 trigonal bipyramid tetrahedron tetrahedron tetrahedron tetrahedron 24 e- see saw24 e- see saw 26 e- 24 e- 20 e- 18 e- 8 e e- e- 16 e- 24 e- 24 e- + ClO 32 e- 8 e- 8 e- e- 4 trigonal CHplanar 4 NH 32 e- 8 e- tetrahedron tetrahedron pyramid 4 CI 2 H trigonal planar 24 e e- trigonal pyramid trigonal planar 18 bent e º trigonal planar trigonal planar 32 e- SiF8 e- 8 e- e- 1 double bond 1 double bond 5 bent bent 120º distorted 18 e º bent 109.5º PCl trigonal planar bent 120º 1 double bond 1 double bond8 e- 20 e- tetrahedron tetrahedron tetrahedron tetrahedron 5 bent 120º bent 120º bent 120º bent 120º tetrahedron (~120) tetrahedron tetrahedron tetrahedron tetrahedron tetrahedron 26 e- tetrahedron 20 e- tetrahedron 8 e- trigonal pyramid 2 SO bent 109.5º bent 3 NH 26 e- (~109.5) 3 H 3 O BrF e- SF 5 8 e- N 2 O ron trigonal pyramid trigonal pyramid trigonal pyramid 8 e- 26 e- 20 e- 26 ared e- pair) (1 unshared 8 e- pair) (1 unshared 8 e- 40 trigonal e- pair) pyramid (2 unshared 48 bent pair) e º ahedron nal pyramid trigonal square pyramid trigonal square octahedron pyramid pyramid square octahedron planar 3 3 ared pair) lanar shape 18 e- nt 120º 3 ahedron 8 e- rahedron 2 F l 4 ramid ef 2 8 e- 20 e- ared pair) nt 109.5º re planar F 3 4 e- eption) nal planar (2 atoms) triple bond double bond 10 e- AsF12 e- (2 atoms) (2 6 BrF14 atoms) 5 e- (2 atoms) O triple bond double bond 3 NO 2 (3 unshared pair) (1 unshared pair) (1 unshared pair) 24 e- (2 unshared pair) 18 e- 18 e- CO O 2 ClO SO O 2 N 12 e- 2 O ClO 3 NO 2 SO 3 4 trigonal 18 e- square SCN pyramid square COtrigonal pyramid 2 SO planar bent square planar 3 NO 120º bent 120º 3 bent 120º N 10 e- 12 e- 2 O ICl CO 4 24 e- O 24 e- 16 e- 16 e- 14 e- 16 e- (2 atoms) (2 atoms) 16 e- (2 atoms) triple bond double bond (2 atoms) ICl 24 e- 24 e- 16 e BrF e- 4 NO trigonal planar trigonal 2 ClO planar CO O N 2 10 e- (2 unshared pair) 1 ClO 4 ClO ClOCH 12 e- 2 O double bond Ndouble bond+ square planar 10 e- 12 e- NH 2 O 14 e- 16 e- (2 atoms) (2 atoms) 4 CI (2 atoms) 2 H 2 triple bond 14 trigonal planar 32 trigonal planar 1 double bond tetrahedron 1 double bond SCN CO + 16 e- ClO NH 2 SO 3 NO 3 SCN e- double bond 16 e- (2 atoms) 11 e-(2 atoms) 32 e- 19 e- 8 e- 8 e- 20 e- (2 atoms) CO 2 SO 3 NO (2 unshared pair) (2 unshared triple pair) bond free double radical bond tetrahedron tetrahedron tetrahedron tetrahedron free radical 3 24 e- 24 e- square planar square 16 e- 16 e- 16 e- 4 CHplanar 24 e- 2 O double bond O 24 e- 3 NO bent 2 SOtrigonal 2 planar trigonal planar BF 4 8 e- CH trigonal planar trigonal planar 1 double bond 1 double bond 1 double bond 1 double bond 32 Oe- tetrahedron tetrahedron 2 ClO O 24 e- 18 e- 18 e- 18 e- 3 ClOO 3 NNO CI 2 2 H 2 12 e- 2 O 14 e- BF N 2 O 24 e- 18 e- 18 e e e- NO e- NO SO 4 SO 3 NH 3 H 3 O 16 e- 18 e- (2 atoms) trigonal CHplanar 2 O Obent 3 120º NO 2 bent 120º 20 SO CH CF (2 atoms) 2 O O 3 NO 2 SO 24 e- (2 atoms) 2 e- double bond 10 e- 3 H + trigonal planar bent 120º bent 120º SCN SCN CO 2 SO 3 CO NO 2 SO 3 NO 3 bent 120º 3 24 e- 24 e- 16 e- 16 e- (exception) 32 e- 24 e-26 e e- trigonal planar trigonal planar 16 e- 16 e- e- 8 e- trigonal planar tetrahedron trigonal trigonal planar pyramid trigonal planar 1 double bond 1 double bond pyramid trigonal pyramid 2 bent 120º 24 1 e- 26 double e- bond 18 e- 1 double bond (exception) (triple 18 e- 18 e- 24 e- 18 e- 18 e- tetrahedron 18 e- trigonal planar bent 120º bent 120º bent 120º PCl trigonal planar 5 SF bent 120º bent 4 bond) SeCl trigonal planar oops 120º bent 120º 4 tetrahedron + ClO 4 CH 4 NH 4 CI 2 H 2 SO SO 3 NO 32 e- 8 e ClO 3 NO (1 unshared 4 CH 3 pair) (1 unshared pair) ClO 3 8 SeF e- 2 H20 2 e- CH O ClO 2 4 NH 2 O 4 CI O CH 3 2 H 2 ClO NO 2 O O 2 4 CH 4 SO 3 NO 2 SO 2 NH 2 18 e- 4 CI 2 SF H 2 4 SeCl 4 (1 unshared pair) (1 unshared pair) SF 3 XeCl IF 2 trigonal bipyramid trigonal bipyramid see saw see saw O 3 NO 2 2 SiF SO 40 SO e PCl SO 5 3 NH SF 43 HSeCl 3 O e- 2 SO 4 SO 3 NH 3 NH 3 H 3 O + 26 e- 3 H 3 O e- 2 8 e- SO 4 SO 3 40 NH e- 3 H 3 O + 18 (2 e- NO unshared 2 pair) 18 e- (3 SO unshared 40 2 tetrahedron e- ClO 18 pair) e- 4 (3 unshared trigonal 40 CH pair) e- pyramid 4 ClO trigonal NH 4 + pyramid (1 unshared 4 CH CI trigonal pair) (1 unshared 2 4 pyramid H 2 NH 4 CI 2 H 2 pair) 32 e- 26 e- 8 e- 8 e- bent 120º T-shape bent 120º trigonal bent 120º 32 e- 18 e- 26 e- 18 bipyramid trigonal e- bipyramid 32 e- 8 e- 8 e- 20 e- 32 e- 8 e- 8 e- 8 e- see 8 saw e- ClF trigonal pyramid trigonal pyramid trigonal pyramid SO 2 NO tetrahedron trigonal pyramid trigonal pyramid trigonal pyramid 3 20 see e- tetrahedron tetrahedron saw SF 3 tetrahedronxecl tetrahedron 2 IF tetrahedron tetrahedron tetrahedron tetrahedron 32 e- bent 120º 26 e- bent 120º 8 e- 8 e- 2 2 tetrahedron trigonal pyramid trigonal pyramid trigonal pyramid 18 e- (2 unshared pair) (2 unshared pair) + 18 e- (3 unshared pair) (3 unshared pair) bent 120º CH bent 120º ClO 4 NH 3 SF SeF 4 CI H O 2 2 T-shape T-shape ClO ClO 3 SeF 2 H 2 O ClO 2 8 e- 6 + BrF ClF ClO 3 8 e- 6 SiF 20 e- 3 SF SeF XeCl H 2 O ClO 26 e- 2 IF 2 26 e e e- 20 e- 20 e- 2 8 e- 20 e- tetrahedron 26 NH e- tetrahedron 20 e- tetrahedron 8 20 e- trigonal pyramid bent 109.5º bent distorted 109.5º bent 109.5º trigonal pyramid ClO 4 CI 3 bent 109.5º SeF 2 bent 2 48 H40 trigonal e- distorted 2 SO e- pyramid 4 SO 40 bent e-109.5º 3 SO bent distorted NH 4 3 SO 109.5º Hbent º O + NH 3 H 3 O + octahedron ( º H 2 bent 109.5º 8 e- octahedron unshared pair) 32 e- 20 e- Ooctahedron (2 unshared 26 ClO pair) e- 32 e- 2 (3 unshared 8 e- 26 e- pair) (3 unshared 8 e- 8 e- 8 e- pair) + 2 tetrahedron trigonal pyramid tetrahedron trigonal pyramid T-shape T-shape I 20 e- 3 trigonal trigonal pyramid pyramid trigonal SF 6 pyramid trigonal BrF 6 pyramid SiF 6 bent 109.5º octahedron octahedron octahedron SeF 2 20 e- bent 109.5º NH 3 BrF H 2 O 4 8 e- (2 unshared pair) bent distorted 109.5º square planar NO + 10 e- (triple bond) octahedron octahedron octahedron octahedron 16 e- 16 e- 10 e- 14 e- (2 atoms) H 2 O 8 e- bent distorted 109.5º bent distorted 109.5º XeF H 3 O + I 4 3 ClO 3 SF SeF 6 2 ClO 2 ClO NO 2 20 e- bent 109.5º AsF 6 11 e- 20 e- free radical bent 109.5º double (3 unshared bond pair) octahedron NO ICl 4 oops O 2 12 e- (2 atoms) ClO BrF e- free radical (1 bent unshared pair) square pyramid CF BrF 3 H 4 Two atom molecules, 26 e- (2 unshared pair) tetrahedron (2 unshared pair) always square planar square planar ClO octahedron + ClO BrF H 32 O 6 SeF ClO e- 8 e- 20 e-20 e- trigonal bent distorted pyramid AsF 109.5º bent 6 bent 109.5º 109.5º octahedron SF 5 (3 unshared pair) octahedron XeF 4 ICl 4 8 e- BrF 5 (1 unshared pair) CO square pyramid 2 16 e- BrF 4 (1 unshared pair) (2 unshared pair) square pyramid (2 unshared pair) square planar square planar NOBF 3 11 e- 24 e- free radical (exception) double bond trigonal planar N 2 O 24 e- trigonal planar 1 double 16 e- bond SiF 6 2 bent distorted 109.5º octahedron (2 unshared pair) square planar ClONO e- 10 e- free radical (triple bond) bent 24 e- trigonal planar 1 double bond H 2 O SF 5 (1 unshared pair) square pyramid NO 11 e- free radical double bond (3 unshared pair) octahedron ClO 2 SCN XeF 20 e- bent 109.5º 4 16 e- (2 unshared pair) square planar ClO 2 19 e- free radical bent NOClO CF 3 H 14 e- 26 e- (2 atoms) oops tetrahedron (1 unshared pair) square pyramid BrF 4 (2 unshared pair) square planar CH NO 2 O + 24 e- trigonal 10 planar e- (triple bond) O 2 12 e- (2 atoms) double bond (1 unshared pair) square pyramid NO 3 24 e- trigonal planar 1 double bond O 3 18 e- bent 120º N 2 O 16 e- NO 11 e- free radical double bond NO oops CO 10 e- (2 atoms) triple bond 4 (2 unsh squar Cl 19 free b CF 2 tetra 31

32 trigonal bipyramid see saw T-shape SiF 5 SiF 5 trigonal bipyramid XeCl 2 (3 unshared pair) trigonal bipyramid ClF 3 SF 4 (2 unshared pair) (1 unshared pair) see T-shape saw I 3 octahedron SF 3 AsF 6 (2 unshared pair) T-shape (3 unshared pair) octahedron ICl 4 IF 2 (1 unshared pair) 5, 6 domains see saw PClI PCl 5 SF e- octahedron 4 trigonal bipyramid SF 3 trigonal bipyramid (1 unshared pair) see saw XeCl 2 (2 unshared pair) octahedral T-shape AsF 6 + SF 6 BrF 6 48 SeCl e- 4 square pyramid square NO + NO planar octahedron 11 e- 19 e- (2 unshared pair) 40 e (2 unshared pair) free radical free radical (3 unshared pair) square planar (3 unshared square pair) planar double bond octahedronbent (3 unshared pair) (1 unshared pair) octahedron square pyramid BF 3 24 e- (exception) trigonal planar (3 unshared pair) octahedron octahedron BrF octahedron e- octahedron (3 unshared pair) (1 unshared pair) (1 unshared pair) (2 unshared pair) SeCl 4 octahedron square pyramid square pyramid square planar (2 unshared (1 unshared pair) pair) (3 unshared pair) (3 unshared SF pair) T-shapesee saw ICl 5 4 BrF 4 48 NO e- ClO 2 SiF (1 unshared pair) (2 unshared 5 PCl pair) (2 unshared 5 SF 4 11 e- SeCl 4 19 e- pair) square free pyramid radical free radical square planar square planar(1 unshared double pair) bond (1 unshared pair) bent trigonal bipyramid trigonal bipyramid see saw see saw SF 6 octahedron BrF 5 (1 unshared pair) square pyramid BrF 6 + octahedron SF 5 (1 unshared pair) square pyramid XeCl 2 (3 unshared oops pair) XeF 4 XeCl 2 SF 3 tetrahedron BrF 4 IF 2 40 (2 e- unshared pair) (2 unshared pair) + 2 (2 unshared square pair) BrF planar (3 6 unshared SiF pair) 6 square (3 unshared planar pair) T-shape octahedron octahedron BrF 4 INO 3 ClO + SF 2 AsF 6 BrF 6 6 BrF 5 SF 5 XeF 4 NO + AsF NO 6 BrF 5 10 e- ICl 4 BrF 4 CF 3 NO H 26 e- (triple bond) 48 (3 e-unshared pair) (1 unshared pair) 11 e- oops tetrahedron (2 unshared pair) (2 unshared pair) trigonal bipyramid ClF 3 (2 unshared pair) T-shape AsF 6 ClF BF 3 3 octahedron square planar trigonal bipyramid SF 3 SF 3 octahedron (1 unshared pair) see saw BrF 5 24 e- 10 e- (exception) (triple bond) (2 unshared trigonal pair) planar(2 unshared pair) T-shape T-shape I 3 octahedron SF 6 octahedron IF 2 SiF 6 2 XeCl 2 (3 unshared pair) (1 unshared pair) square pyramid SF 5 octahedron SF 5 IF 2 (1 unshared pair) see saw IF 2 (3 unshared pair) SiF 6 2 XeF 4 CF 3 H 26 e- (3 unshared pair) (2 unshared pair) square planar SiF 6 2 octahedron ClO XeF 4 2 (1 unshared pair) 19 e- (2 unshared pair) square pyramidfree radical square pyramid free radical square planar square planar double bond bent SiF 6 2 octahedron BrF 5 (1 unshared pair) square pyramid ICl 4 (2 unshared pair) square planar 32

33 Unit I Chapters 8 & 9 The clicker Review

34 The molecular geometry of SO 3 2 is (Before you decide, draw a Lewis structure.) 1. trigonal pyramid 2. trigonal planar 3. square planar 4. tetrahedron 5. octahedron 6. T-shaped 7. see-saw 8. bent 9. 34

35 The molecular geometry of SO 3 2 is (Before you decide, draw a Lewis structure.) 1. trigonal pyramid 2. trigonal planar 3. square planar 4. tetrahedron 5. octahedron 6. T-shaped 7. see-saw 8. bent 9. 26e O SO O tetrahedron domains, 1 unshared pair trigonal pyramid 35

36 The hybridization around the Si atom in SiS 2 is (Before you decide, draw a Lewis structure.) 1. sp 2. sp 2 3. sp 3 4. sp 3 d 5. sp 3 d 2 36

37 The hybridization around the Si atom in SiS 2 is (Before you decide, draw a Lewis structure.) 1. sp 2. sp 2 3. sp 3 16e S Si S 4. sp 3 d 5. sp 2 d 2 2 domains, sp hybridization 37

38 The hybridization around the S atom in SO 2 is (Before you decide, draw a Lewis structure.) 1. sp 2. sp 2 3. sp 3 4. sp 3 d 5. sp 3 d 2 38

39 The hybridization around the S atom in SO 2 is (Before you decide, draw a Lewis structure.) 1. sp 2. sp 2 3. sp 3 18e O S O 4. sp 3 d 3 domains sp 2 5. sp 3 d 2 39

40 The bond angles in SO 3 are º 2. Less than 109.5º 3. Greater than 109.5º 4. Less than 120º 5. Both greater than and less than 120º 40

41 The bond angles in SO 3 are º 2. Less than 109.5º 3. Greater than 109.5º 4. Less than 120º 5. Both greater than and less than 120º 24e O S O O 3 domains, and the unshared pair bulges and thus takes up more space However, perhaps the resonance that causes equal bond lengths will also blend the bond angles 41

42 Which of the following molecules are polar? A) CF 4 B) CH 3 F C) CH 2 F 2 1. All of them are polar 2. Both B + C are polar 3. Only A is polar 4. Only B is polar 5. Only C is polar 42

43 Which of the following molecules are polar? A) CF 4 B) CH 3 F C) CH 2 F 2 1. All of them are polar 2. Both B + C are polar 3. Only A is polar 4. Only B is polar 5. Only C is polar F F CF F H HCF H Remember the shape is tetrahedron, not a planar cross, so do NOT place the F s opposite in the cross structure and think that the polarity crosses out the polarity is asymetrically arranged. H HCF F 43

44 The IF 2 ion has how many shared electron pairs, and how many unshared electron pairs around the central I atom? 1. 2, , , , , 2 44

45 IF 2 ion has how many shared electron pairs, and how many unshared electron pairs around the central I atom? 1. 2, , , , , 2 22e F I F 45

46 The electron domain geometry on the central atom of this molecule is 1. Trigonal planar 2. Trigonal bipyramid 3. Tetrahedron 4. Trigonal pyramid 5. Linear 46

47 The electron domain geometry on which this molecule is based is 1. Trigonal planar 2. Trigonal bipyramid 3. Tetrahedron 4. Trigonal pyramid 5. Linear The trigonal pyramidal shape must be caused by an unshared pair. 47

48 Select the atom(s) below that could possibly be the central atom of this molecule. Select all that apply. 1. C 2. P 3. O 4. Al 5. There is no way of knowing 48

49 Select the atom below that could possibly be the central atom of this molecule. 1. C 2. P 3. O 4. Al 5. There is no way of knowing The unshared pair and three bonding pair mean that the central atom must have 5 valence electrons. Maybe.it could be C if you consider the unshared pair to be a single electron = free radical 49

50 The shape of the electron domains in this molecule can be Select all that apply. 1. Trigonal planar with no unshared pairs 2. Trigonal bipyramid with 2 unshared pairs 3. Tetrahedron with 1 unshared pair 4. Trigonal pyramid with 1 unshared pairs 5. None of the above 50

51 The shape of the electron domains in this molecule is most likely 1. Trigonal planar with no unshared pairs 2. Trigonal bipyramid with 2 unshared pairs This is not a valid choice because trig bipyr unshared pairs are in the equatorial positions not axial, so 2 unshared pair would be T-shape 3. Tetrahedron with 1 unshared pair 4. Trigonal pyramid with 1 unshared pairs 5. None of the above 51

52 For each molecule, how many unshared pair are on each molecule? 1. 0, 0, , 1, , 0, , 1, , 0, 1 52

53 For each molecule, how many unshared pairs are on each molecule? 1. 0, 0, , 1, , 0, , 1, , 0, 1 53

54 What are the total number of nonbonding pair(s) of electrons on the central Si atom of SiS 2?

55 What are the total number of valence nonbonding pair(s) of electrons on the central Si atom of SiS 2? S Si S 55

56 Chemistry Humor 56

57 In the molecule HCN, how many σ and how many π bonds total? 1. 2 σ, 0 π 2. 1 σ, 1 π 3. 2 σ, 1 π 4. 2 σ, 2 π 5. 2 σ, 3 π 57

58 In the molecule HCN, how many σ and how many π bonds total? 1. 2 σ, 0 π 2. 1 σ, 1 π 3. 2 σ, 1 π 4. 2 σ, 2 π 5. 2 σ, 3 π 2 σ H C N 2 π 58

59 The hybridization of the sulfur in methyl mercaptan is 1. sp 2. sp 2 3. sp 3 4. sp 3 d 5. sp 3 d 2 methyl mercaptan (also known as ethanethiol) is a colorless gas with a smell like rotten cabbage. It is released from animal feces. It occurs naturally in certain foods, such as some nuts and cheese. It is also one of the main chemicals responsible for bad breath and the smell in flatulence. It is added in very small quantities to CH 4, an odorless gas, so that leaks will be detected. 59

60 The hybridization of the sulfur in methyl mercaptan is 1. sp 2. sp 2 3. sp 3 4. sp 3 d 5. sp 3 d 2 There are two unshared pairs on the S 60

61 Draw a valid Lewis structure for butanol. How many isomers can be drawn only making alcohols? Enter a number. 61

62 Draw a valid Lewis structure for butanol. How many isomers can be drawn for this molecule? 4 62

63 Draw a valid Lewis structure for pentane. How many isomers can be drawn for this molecule? Enter a number. 63

Lewis structures show the number and type of bonds between atoms in a molecule or polyatomic ion.

VSEPR & Geometry Lewis structures show the number and type of bonds between atoms in a molecule or polyatomic ion. Lewis structures are not intended to show the 3-dimensional structure (i.e. shape or geometry)