Bond Strength Bond energy D Energy required to break a bond between two atoms

Bond strength bond energy d energy required to break

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Bond Strength Bond energy (D) : Energy required to break a bond between two atoms Values listed are averages As bond energy increases, bond length tends to decrease
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Bond Energy and Enthalpy Bond energies can be used to estimate rxn H = D(bonds broken) – D(bonds formed) Example: CH 4 (g) + Cl 2 (g) CH 3 Cl(g) + HCl(g)
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Molecular Shapes V alence S hell E lectron P air R epulsion Electrons pairs seek to be as far apart as possible Predicts shapes by determining the arrangement which maximizes the distance between electron pairs
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VSEPR Bond Pairs: Any bond between two atoms is a Bond Pair For VSEPR, multiple bonds are considered to be a single Bond Pair Lone Pairs: Nonbonding pairs of electrons around an atom
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VSEPR Electron - pair geometry: Linear (2 pairs) Trigonal planar (3 pairs) Tetrahedral (4 pairs) Trigonal bipyramidal (5 pairs) Octahedral (6 pairs)
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VSEPR Molecular geometry: the shape formed by the atoms in the molecule Nonbonding domains need more room than bonding domains Nonbonding domains can alter bond angles
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Polarity of Molecules For a molecule to be polar: the bonds must be polar the dipole vectors must not cancel each other out Generally, for any molecule AB x : It will be non-polar if all domains are bonding It will be polar if there are nonbonding domains (exceptions = linear, square planar)
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