CHM136H1 Lecture : Tutorial 1.pdf

• School: UTSG
• Department: Chemistry
• Course: CHM136H1
• Professor: C.Scott Browning

Document Summary

2 models for describing covalent bonding: valence bond theory and molecular orbital theory. Valence bond theory: covalent bond forms when two atoms approach each other closely and a single occupied orbital on one atom overlaps a single occupied orbital on the other atom. Electrons now paired in the overlapping orbitals and attracted to nuclei of both atoms, bonding the atoms together. Overlapping orbitals in h2 have elongated egg shape. The h - h bond is cylindrically symmetrical. Product has 436 kj/mol less so is more stable than reactants. The h-h bond has a bond strength of 436 kj/mol. If hs are too close, will repel each other because both are positively charged, if too far, can"t share electrons - optimum distance called bond length. 1. 6 sp3 hybrid orbitals and the structure of methane. In 1931, linus pauling showed that an s orbital and three p orbitals can hybridize to form four equivalent atomic orbitals of tetrahedral orientation - sp3 hybrids.