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Use of Bond Equations in Solving Problems. Ray A. Gross Jr Prince George’s Community College. How many bonds are present in benzene, C 6 H 6 ?. Consider Water, H 2 O. For C 6 H 6. B = ½[(6 x 4) + (6 x 1)] B = ½(24 + 6) B = 15. Alternative Solution Hydrocarbons.
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Use of Bond Equations in Solving Problems Ray A. Gross Jr Prince George’s Community College
For C6H6 • B = ½[(6 x 4) + (6 x 1)] • B = ½(24 + 6) • B = 15
Alternative Solution Hydrocarbons • Total Bonds = Bonds (corresponding saturated, acyclic compound) minus number of p bonds and rings in the structure.
BD for All Compounds BD = 1 – ½(X – N – 2C – 3P – 4S) X = number of monovalent atoms N = number of trivalent atoms C = number of tetravalent atoms P = number of pentavalent atoms S = number of hexavalent atoms
Taxol, C47H51NO14 , has 7 rings.How many s bonds does it have? • + r = 1 – ½(X – N – 2C – 3P – 4S) p + r = 1 – ½[(51 – 1 – 2(47)] = 23 p = 23 – 7 = 16 B = ½[47(4) + 51 + 3 + 14(2)] = 135 s = 135 – 16 = 119
How many bonds are in HPO4-2? B = ½[1 + 5 + 4(2) – 2] = 6
What’s all of this good for? • Increases students knowledge of structure and bonding. • Possibly use DB to classify reactions.
Derive an Eqn for Btot in an Alkyne. B = Bsat – BD B = 3n + 1 – 2 B = 3n - 1