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How I would study: • Look over exams • Look over review sheets • Difficulties? Work HW problems, examples from the text • Start early: where are your problem spots? Chapter 1: Introduction • Dimensional analysis – Change among units (eg. feet vs. meters) – Prefixes (1 kilogram/1000 grams) • Density (d = m/v) • Scientific notation – Don’t worry about sig. figs Chapter 2: Atomic Theory • Chemical formulas – Molecular formula vs. empirical formula – Naming compounds • Ionic (Table 2.3) vs. molecular – Atomic number Table 2.3 Chapter 3: Stoichiometry • Atomic mass, molecular mass • Molar mass • Percent composition/determining empirical formulas • Chemical equations – What do coefficients tell you? Chapter 3: Stoichiometry • Limiting reagents – Assume each reagent is limiting, calculate theoretical yields. Lower result? – Actual, theoretical, percent yields Chapter 4: Reactions in aqueous solutions • Electrolytes • Precipitation reactions – Solubility – Molecular/ionic/net ionic equations • Acid/base reactions • Oxidation-reduction reactions – Writing half-reactions – Oxidation numbers Table 4.2 Chapter 4: Reactions in aqueous solutions • Molarity • Gravimetric analysis – Essentially limiting reagent problems • Acid-base titrations – #mol acid = #mol base Chapter 5: Gases • Ideal gas equation (PV = nRT) • Partial pressures – eg. if a gas is collected “over water,” the total pressure comes from the gas and water’s vapor pressure • Mole fraction Px = nxPT Chapter 6: Energy relationships in chemical reactions • Endothermic vs exothermic • DE = q + w – q = heat (thermal energy) – w = work (w = -PDV) • Enthalpy/thermochemical equations – DH = H9products) – H(reactants) – DH of formation • Indirect vs. direct methods Chapter 6: Energy relationships in chemical reactions • Calorimetry: find the energy change in a reaction (or process) qcal + qrxn = 0 qrxn = -qcal q = msDt = CDt Ch 7: Electronic structure of atoms • Atomic orbitals – s, p • Electron configurations – Quantum numbers – 1s2 2s2 2p6 … • Pauli exclusion principle • Hund’s rule Fig. 7.21 Ch 8: The Periodic Table • Isoelectronic • Effective nuclear charge – Atomic/ionic radius – Ionization energy – Electron affinity Ch 9: The Covalent Bond • • • • Lewis structures Formal charge Resonance Electronegativities – Covalent/polar covalent/ionic • Bond energies DH = BE(reactants) – BE(products) Ch 10: Molecular Geometry & Hybridization of Atomic Orbitals • Geometries (VSEPR model) • Hybridization • Sigma (s) vs. pi (p) bonds Table 10.1 No lone pairs Table 10.2 With one pairs Table 10.4 Hybridization Ch 12: Intermolecular forces • Boiling, melting points • Dipole: molecule must be polar – Electronegativity AND geometry • Ionic • Ion/dipole • Dipole/dipole – Hydrogen bond • Induced dipole • Dispersion Ch 14: Chemical Kinetics • Rate of reaction – Decrease of reactant/increase of product – Depends on coefficients • Rate laws Rate = k[A]x[B]y • Half-life (first order) • Rate vs. temperature – Collision frequency – Activation energy – Arrhenius equation Ch 15: Chemical Equilibrium • Equilibrium constant • Direction of a reaction – Q vs. Kc • Le Châtlier – Concentration (adding reactant or product) – Pressure – Temperature Ch 16: Acids and Bases Ch 17: Buffers • Conjugate acid/base pairs • Water: both an acid and a base – Kw = 10-14 • Strong vs. weak acids • Ka & Kb • Calculate pH, given pKa and concentration of a weak acid • Calculate concentration of a weak acid to give a pH (given pKa) Ch 18: Thermodynamics • Entropy (S): disorder – Increased S (more disorder) favorable – Decreased H (less thermal energy) favorable DG = DH - TDS