Atomic Orbital Hybridization of carbon.pptx
- 2. What is the difference between a petrol car and a hybrid car? Why are such vehicles called hybrid? What other examples of any hybrid substances do you know?
- 3. Introduction to Bond Formation • A bond is formed by the overlapping of valence shell half filled orbitals. • The valency of an atom is equal to the number of unpaired electrons. • The equivalent bonds are the bonds of same energy and same length. • Only equivalent orbitals can form equivalent bonds. • Draw displayed structure of methane.
- 4. Atomic Orbital Hybridization Methane (CH4) It is confirmed experimentally that the carbon atom in methane (CH4) and other alkanes has a tetrahedral geometry, and all the four bonds have identical lengths. Configuration of C 1s2 2s2 2p2 Can Carbon form four covalent bond with this configuration?
- 5. Atomic Orbital Hybridization • To form four bonds, carbon must have four unpaired electrons. For that carbon excites one of its electron from 2s to 2pz. • This configuration of carbon can form its tetravalency, but the bond formed will be different. • To form equivalent bond, carbon must have four equivalent bonds.
- 6. Atomic Orbital Hybridization • In carbon one s and three p orbitals of the excited state of carbon are mixed to form four identical orbitals of same size, shape, and energy orbitals. • “The phenomenon of mixing atomic orbitals of different shapes and slightly different energies to give a set of hybrid orbitals having same energy and same shape. • These newly formed orbitals are called sp3 hybrid orbitals. • These four sp3 hybrid orbitals arranged themselves tetrahedrally.
- 7. Atomic Orbital Hybridization • These four sp3 -hybridized orbitals arrange in a tetrahedral geometry and make bonds by overlapping with the s orbitals of four hydrogens. • The bonds are formed by the head-on overlap of orbitals (sp3 orbitals of the carbon and s orbital of each hydrogen.) are called σ (sigma) bonds because the electron density is concentrated on the axis connecting the C and H atoms.
- 8. Summery of sp3 Hybridization Alkanes are always sp3 hybridized. sp3 hybridized atom have four degenerate orbitals. Molecules with sp3 hybridization possess tetrahedral (e-pair geometry).
- 9. Atomic Orbital Hybridization • Ammonia is another example of sp3 hybridization. • Nitrogen mix its 2s with 2px,2py and 2pz to form four (4) sp3 hybridized orbitals. • Three of these hybrid orbitals have an unpaired electron while fourth contain a pair of electron. • In NH3 three H-atoms overlapped with half filled sp3 orbitals whereas the fourth contain a lone pair of electrons.
- 10. Try yourself…. • In the molecule of Ethane (C2H6), the carbon atoms undergo A. sp hybridization C. sp2 hybridization B. sp3 hybridization D. d2 sp3 hybridization • The bond angles in a molecule with sp3 hybridization are: A. 90° B. 109.5° C. 120° D. 180° • Which molecule does NOT exhibit sp3 hybridization? A. CH4 B. NH3 C. H2O D. CO2 00:01
- 11. Let’s take the example of BF3. sp2 hybridization
- 13. Atomic Orbital Hybridization Let’s take the example of ethene, which contains sigma as well as pi bond between two carbon atoms.
- 14. Atomic Orbital Hybridization • In ethene sigma() bonds are formed by • sp2 -sp2 overlapping of two carbon atoms. • sp2 -s overlapping of carbon and hydrogen atom. • Pi( bond is formed by the side wise overlapping of two unhybrid p orbitals. • The bond angle in ethene is 120 with triangular planer geometry.
- 15. Let’s consider the example of ethyne (Acetylene), in which carbon atoms have two pi bonds. sp hybridization
- 16. The molecule with trigonal planer geometry have sp3 d hybridization. These molecules have 5 electron pairs around the central atom. The first thing to mention here is that the elements capable of adopting trigonal bipyramidal or octahedral geometry must be in period 3 or higher. It form by the mixing of one s, three p and a d orbitals. sp3 d hybridization
- 17. sp3 d2 hybridization Let’s consider the structure of sulfur hexafluoride, SF6. The central atom has six atoms connected, and therefore, it needs six equivalent orbitals, which is achieved by the sp3 d2 hybridization. S 1s2 2s2 2p6 3s2 3p4
- 18. Hydrogen Bonding and Water • Hydrogen bonding have great impact on the properties of HF, H2O and NH3. • Water is more affected by hydrogen bonding. • Water has exceptionally high boiling point than other hydrides. GROUP IV GROUP V GROUP VI GROUP VII M r BOILING POINT / C° 10 0 0 - 16 0 14 0 50 10 0 H2O HF NH3 CH4
- 19. Hydrogen Bonding and Water • Ice has less density than water. • This is because of the presence of 9% empty spaces in ice as compared to the liquid water. • These spaces are generated because of H-bonding during the ice formation
- 20. Practice Problems • In which of the following molecules is the central atom's hybridization sp? A. CH4 B. SO2 C. BeCl2 D. NH3 • The importance of hybridization in chemistry is: A. It explains the shapes of molecules. B. It predicts the reactivity of molecules. C. It determines the polarity of molecules. D. All of the above. • Which type of hybridization results in a tetrahedral molecular geometry? A. sp B. sp2 C. sp3 D. d2 sp3
- 21. Practice Problems • Which type of hybridization is occurring in the carbon atoms of Benzene? A. sp3 d2 B. sp3 C. sp3 d D. sp2 • The importance of hybridization in chemistry is: A. It explains the shapes of molecules. B. It predicts the reactivity of molecules. C. It determines the polarity of molecules. D. All of the above. • Which type of hybridization results in a tetrahedral molecular geometry? A. sp B. sp2 C. sp3 D. d2 sp3