wade英文原版有机化学课件—01

Chapter 1Introduction and Review,Organic Chemistry, 5th EditionL. G. Wade, Jr.,Jo BlackburnRichland College, Dallas, TXDallas County Community College District 2003, Prentice Hall,Chapter 1,2,Definitions,Old: “derived from living organisms”New: “chemistry of carbon compounds”From inorganic to organic, Whler, 1828,=,Chapter 1,3,Atomic Structure,protons, neutrons, and electronsisotopes,=,Chapter 1,4,Atomic Orbitals,2s orbital (spherical),Chapter 1,5,Electronic Configurations,Aufbau principle: Place electrons in lowest energy orbital first.Hunds rule: Equal energy orbitals are half-filled, then filled.,Chapter 1,6,Table 1-1,=,Chapter 1,7,Bond Formation,Ionic bonding: electrons are transferred.Covalent bonding: electron pair is shared.,=,Chapter 1,8,Lewis Structures,Bonding electronsNonbonding electrons or lone pairs,Satisfy the octet rule! =,Chapter 1,9,Multiple Bonding,=,Chapter 1,10,Dipole Moment,Amount of electrical charge x bond length.Charge separation shown by electrostatic potential map (EPM).Red indicates a partially negative region and blue indicates a partially positive region.,=,Chapter 1,11,Electronegativity and Bond Polarity,Greater EN means greater polarity,=,Chapter 1,12,Calculating Formal Charge,For each atom in a valid Lewis structure:Count the number of valence electronsSubtract all its nonbonding electronsSubtract half of its bonding electrons,=,Chapter 1,13,Ionic Structures,Chapter 1,14,Resonance,Only electrons can be moved (usually lone pairs or pi electrons).Nuclei positions and bond angles remain the same.The number of unpaired electrons remains the same.Resonance causes a delocalization of electrical charge.,Example=,Chapter 1,15,Resonance Example,The real structure is a resonance hybrid.All the bond lengths are the same.Each oxygen has a -1/3 electrical charge. =,Chapter 1,16,Major Resonance Form,has as many octets as possible.has as many bonds as possible.has the negative charge on the most electronegative atom.has as little charge separation as possible.,Example=,Chapter 1,17,Major Contributor?,Chapter 1,18,Chemical Formulas,Full structural formula (no lone pairs shown)Line-angle formulaCondensed structural formulaMolecular formulaEmpirical formula,CH3COOHC2H4O2CH2O =,Chapter 1,19,Calculating Empirical Formulas,Given % composition for each element, assume 100 grams.Convert the grams of each element to moles.Divide by the smallest moles to get ratio.Molecular formula may be a multiple of the empirical formula. =,Chapter 1,20,Arrhenius Acids and Bases,Acids dissociate in water to give H3O+ ions.Bases dissociate in water to give OH- ions.Kw = H3O+ OH- = 1.0 x 10-14 at 24CpH = -log H3O+ Strong acids and bases are 100% dissociated.,=,Chapter 1,21,Brnsted-Lowry Acids and Bases,Acids can donate a proton.Bases can accept a proton.Conjugate acid-base pairs.,Chapter 1,22,Acid and Base Strength,Acid dissociation constant, KaBase dissociation constant, KbFor conjugate pairs, (Ka)(Kb) = KwSpontaneous acid-base reactions proceed from stronger to weaker.,Chapter 1,23,Determining Relative Acidity,Electronegativity Size Resonance stabilization of conjugate base =,Chapter 1,24,Electronegativity,As the bond to H becomes more polarized, H becomes more positive and the bond is easier to break.,=,Chapter 1,25,Size,As size increases, the H is more loosely held and the bond is easier to break.A larger size also stabilizes the anion.,=,Chapter 1,26,Resonance,Delocalization of the negative charge on the conjugate base will stabilize the anion, so the substance is a stronger acid.More resonance structures us