Vsepr theory & hybridization

VSEPR Theory & Hybridization

1. VSEPR Theory & Hybridization Made by:- Sauhard Singhal

2. The shape of the molecule is determined by repulsions between all of the electron present in the valance shell. Electron pairs in the valence shell of the central atom repel each other and align themselves to minimize this repulsion. Lone pair electrons takes up more space round the central atom than a bondpair . Lone pair attracted to one nucleus, but bond pair is shared by two nuclei. The minimum repulsions to the state minimum energy and maximum stability of the molecule. VSEPR Theory

3. Lone pair -Lone pair  Lone pair -Bond pair  Bond pair-Bond pair Repulsion strengths

4. Triple bond > double bond > single bond Repulsion strengths

5. Presence of lone pairs on the central atom causes slight distortion of the bond angles from the ideal shape. The magnitude of repulsions between bonding pairs of electrons depends on the electronegativity difference between the central atom &the other atoms .

6. Determine the central atom. Draw the electron dot structure and bar diagram Find arrangement of electron pairs. Find arrangement of bonding pairs. Determine the geometry based on of bonding pairs. Steps in the prediction of geometry

7. BONDED PAIRS OF ELECTRONS ONLY SHAPES OF MOLECULES CONTAINING

8. There are two electron pairs in the valance shell of Beryllium . [1s 2 2s 2 ] Molecular geometry- Linear arrangement Central atom with Two Electron Pairs H H Be

9. Three electron pairs in the valance shell of Boron . [1s 2 2s 2 2p 1 ] Molecular geometry- Trigonal Planar arrangement Central atom with Three Electron Pairs Trigonal Planar B F F F

10. Central atom with Four Electron Pairs Tetrahedral Four electron pairs in the valance shell of Carbon . [1s 2 2s 2 2p 2 ] Molecular geometry- Tetrahedral Bond angle -109.5⁰

11. Central atom with Five Electron Pairs Five electrons in the valance shell of Phosphorus . [1s 2 2s 2 2p 6 3s 2 3p 3 ] Molecular geometry- Trigonalbipyramid Bond angle -120⁰ &90⁰

12. Central atom with Six Electron Pairs Six electrons in the valance shell of Sulphur . [1s 2 2s 2 2p 6 3s 2 3p 4 ] Molecular geometry- Octahetral Bond angle-90⁰

13. BONDED PAIRS AS WELL AS LONE PAIRS OF ELECTRONS SHAPES OF MOLECULES CONTAINING

14. Central atom with Four Electron Pairs Tetrahedral Five electrons in the valance shell of Nitrogen . [1s 2 2s 2 2p 3 ] Molecular geometry- Tetrahedral Electron pairarrangement - Trigonal Pyramidal Presence of lonepair causes slight distortion from 109⁰28′ to 107⁰48′

15. Central atom with Four Electron Pairs Tetrahedral Six electrons in the valance shell of Oxygen atom. [1s 2 2s 2 2p 4 ] Molecular geometry- V-Shaped or Bent shape Electron pairarrangement - Tetrahetral Repulsions between Lonepair - Lonepair , Lonepair - Bondpair is possible. It causes slight distortion from 109⁰28′ to 104⁰27′

16. Central atom with Five Electron Pairs Five electrons in the valance shell of Sulphur . [1s 2 2s 2 2p 6 3s 2 3p 4 ] Molecular geometry- seesaw[or distorted octahedron] Electron pair arrangement- Trigonalbipyramidal Lonepair – bondpair repulsion

17. Central atom with Six Electron Pairs Seven electrons in the valance shell of xenon  : 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 5s 2 5p 6 Molecular geometry- square planar Electron pairarrangement - octahedral Lonepair – bondpair repulsion

18. EFFCT OF ELECTRONEGATIVITY Five electrons in the valance shell of Nitrogen . [1s 2 2s 2 2p 3 ] Molecular geometry- Tetrahedral [ e-pairs arrangement ] or Trigonal Pyramidal [VSEPR] Presence of lonepair causes slight distortion from 109⁰28′ to 107⁰48′to102⁰30′ Repulsion between bonpair-bondpair is less in NF 3 than inNH 3 102⁰30′

19.  It fails to predict the shapes of isoelectronic species [CH 4 &NH 4 + ] and transition metal compounds.  This model does not take relative sizes of substituents . Unable to explain atomic orbitals overlap. Limitations of VSEPR

20. Seven electrons in the valance shell of xenon  : 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 4s 2 4p 6 4d 10 5s 2 5p 6 Molecular geometry- Pentagonalbipyramid [VSEPR], DistortedOctahedral [actual] Lonepair – bondpair repulsion

21. Concise Inorganic chemistry-J.D.LEE[Fifth edition]-Black well publishing. Chemistry-Raymond chang . Pictures from Wikipedia- free encyclopedia-www. Wikipedia.org. Pictures from Google Images. Thanks to my Teachers & friends REFERENCES

22. Hybridization

23. The intermixing of two or more pure atomic orbital's of an atom with almost same energy to give same number of identical and degenerate new type of orbital's is known as hybridization. The new orbital's formed are also known as hybrid orbital's. During hybridization, the atomic orbital's with different characteristics are mixed with each other. Hybridization

24. sp sp2 sp3 sp3d sp3d2 sp3d3 Types of Hybridization

25. Intermixing of one 's' and one 'p' orbital's of almost equal energy to give two identical and degenerate hybrid orbital's is called 'sp' hybridization. These sp-hybrid orbital's are arranged linearly at by making 180 ⁰ of angle. They possess 50% 's' and 50% 'p' character. sp Hybridization

26. Intermixing of one 's' and two 'p' orbital's of almost equal energy to give three identical and degenerate hybrid orbital's is known as sp2 hybridization. The three sp2 hybrid orbital's are oriented in trigonal planar symmetry at angles of 120 ⁰ to each other. The sp2 hybrid orbital's have 33.3% 's' character and 66.6% 'p' character. sp2 hybridization

27. In sp3 hybridization, one 's' and three 'p' orbital's of almost equal energy intermix to give four identical and degenerate hybrid orbital's. These four sp3 hybrid orbital's are oriented in tetrahedral symmetry with 109 ⁰ 28' angle with each other. The sp3 hybrid orbital's have 25% ‘s’ character and 75% 'p' character. sp3 hybridization

28. In sp3d hybridization, one 's', three 'p' and one 'd' orbital's of almost equal energy intermix to give five identical and degenerate hybrid orbital's, which are arranged in trigonal bipyramidal symmetry. Among them, three are arranged in trigonal plane and the remaining two orbital's are present above and below the trigonal plane at right angles. The sp3d hybrid orbital's have 20% 's', 60% 'p' and 20% 'd' characters. sp3d hybridization

29. Intermixing of one 's', three 'p' and two 'd' orbital's of almost same energy by giving six identical and degenerate hybrid orbital's is called sp3d2 hybridization. These six sp3d2 orbital's are arranged in octahedral symmetry by making 90 ⁰ angles to each other. This arrangement can be visualized as four orbital's arranged in a square plane and the remaining two are oriented above and below this plane perpendicularly. sp3d2 hybridization

30. In sp3d3 hybridization, one 's', three 'p' and three 'd' orbital's of almost same energy intermix to give seven sp3d3 hybrid orbital's, which are oriented in pentagonal bipyramidal symmetry. Five among the sp3d3 orbital's are arranged in a pentagonal plane by making 72⁰ of angles. The remaining are arranged perpendicularly above and below this pentagonal plane. sp3d3 hybridization

31. ē Pair Hybridization Shape 2 sp linear 3 sp 2 trigonal planar 4 sp 3 tetrahedral, pyramidal, or bent 5 sp 3 d trigonal bipyramidal, trigonal planar, or linear 6 sp 3 d 2 octahedral, square planar, or linear

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