8 CHEMICAL BONDING (e) Oxygen is more electronegative than carbon and attracts electrons from it. Formaldehyde has H f nd dipole Direction of molecular maldehyde dipole moment (f) Nitrogen is more electronegative than carbon Hydrogen cyanide has a dipole moment Direction of bond dipole 1.20 The orbital diagram for sp-hybridized nitrogen is the same as for sp-hybridized carbon, except nitrogen has one more electron 2++ 2y++千 Ground electroni sp hybrid state of nitrogen state of nitrogen The unshared electron pair in ammonia(: NH, )occupies an sp-hybridized orbital of nitrogen. Each N-H bond corresponds to overlap of a half-filled sp hybrid orbital of nitrogen and a ls orbital of h 1.21 Silicon lies below carbon in the periodic table, and it is reasonable to assume that both carbon and silicon are sp-hybridized in H3CSiHy The C-Si bond and all of the C-H and Si-H bonds are o bonds C(2sp)-Si(sp )o bond C(2sp)-H(ls)o bond H- H-C-Si-H Si(3sp)-H(Is)o bond The principal quantum number of the carbon orbitals that are hybridized is 2; the principal quantum number for the silicon orbitals is 3 1. 22 (b) Carbon in formaldehyde(h,c=O)is directly bonded to three other atoms(two hydrogens and one oxygen). It is sp--hybridized (c) Ketene has two carbons in different hybridization states. One is sp-hybridized; the other is sp-hybridized. HC=C=O Bonded to Bonded to three atoms. wo atoms:罗p Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE Website(e) Oxygen is more electronegative than carbon and attracts electrons from it. Formaldehyde has a dipole moment. ( f ) Nitrogen is more electronegative than carbon. Hydrogen cyanide has a dipole moment. 1.20 The orbital diagram for sp3 -hybridized nitrogen is the same as for sp3 -hybridized carbon, except nitrogen has one more electron. The unshared electron pair in ammonia (• •NH3) occupies an sp3 -hybridized orbital of nitrogen. Each N@H bond corresponds to overlap of a half-filled sp3 hybrid orbital of nitrogen and a 1s orbital of hydrogen. 1.21 Silicon lies below carbon in the periodic table, and it is reasonable to assume that both carbon and silicon are sp3 -hybridized in H3CSiH3. The C@Si bond and all of the C@H and Si@H bonds are bonds. The principal quantum number of the carbon orbitals that are hybridized is 2; the principal quantum number for the silicon orbitals is 3. 1.22 (b) Carbon in formaldehyde (H2C?O) is directly bonded to three other atoms (two hydrogens and one oxygen). It is sp2 -hybridized. (c) Ketene has two carbons in different hybridization states. One is sp2 -hybridized; the other is sp-hybridized. H2C C O Bonded to three atoms: sp2 Bonded to two atoms: sp C H H H H H Si H Si(3sp3 C(2sp ) bond 3 ) C(2sp H(1s) bond 3 ) Si(3sp3 ) H(1s) bond Ground electronic state of nitrogen sp3 hybrid state of nitrogen (a) (b) Energy 2s 2p 2sp3 H C N Direction of bond dipole moments in HCN H C N Direction of molecular dipole moment Direction of bond dipole moments in formaldehyde Direction of molecular dipole moment C O H H C O H H 8 CHEMICAL BONDING Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website