HISTORY 1M03 Lecture Notes - Lecture 13: Electronegativity, Micelle, Van Der Waals Force
25 Apr 2021
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Learning outcomes: understand the role of water in our system, analyze different interactions that hold together macromolecules, apple coulomb"s law to describe the force between charged objects. The most abundant substance in living organisms. Makes up >70% of weight of most living organisms. Many non-covalent interactions use water as a solvent (aqueous reactions) Higher melting + boiling point + heat of vaporization than other solvents. Unequal sharing of electrons allow for hydrogen bonding. Composed of one o and two h 2 dipoles. Tetrahedral geometry (4 hydrogen bonds at once) with 104. 5 bond angles (lower than 109. 5 due to the non-bonding orbitals of the oxygen) Covalent bonds are much stronger than non- covalent bonds. They are relatively weak bonds (bde = 23 kj/mol) They can only happen between an electronegative atom like n or o (hydrogen acceptor) and a h attached to another electronegative atom (hydrogen donor)
