Summary - Final Exam Review PDF

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Final Review Equations - Relationships of moles, mass, and volume - PV = nRT - E = hv & c = v - “products minus reactants” - G = G – TS - K = A ^ (-Ea/RT) Stoichiometry - Atoms, molecules, moles - Formulas, molecular weights - Reactions, equations, yields - Limiting reagents - Solutions, concentrations, etc Gases - Molecular picture of gases - Gas law - Gas mixtures, partial pressures - Kinetic energy, speed, temperature - Stoichiometry & Gases Atoms & Light - Waves & Particles - Photons, photoelectric effect

- Energy levels - Orbitals Periodic Properties - Electron configurations - IE, EA, atomic radii, trends Chemical Bonding - Ionic vs. Covalent bonding: electronegativity - Lewis structures - Molecular geometry: Steric # - Sigma & Pi bonds Problem - NCl3 & PCl3 both exist - But only one of these elements (N & P) forms a pentachloride (XCL5). Which one? What shape are these molecules? Chemical Bonding - Orbital overlap model: Hybridization - Delocalized orbital picture leads to band diagrams for solid materials Thermodynamics - State functions - Heat flow, final T’s - First Law - Calorimetry o Measuring E & H - Heat of formations, Hess’s Law, finding H from tabulated data - Second Law - Entropy: molecular disorder

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- Free energy & Spontaneity - Calculating S & G from tabulated data - G = H - TS Example - CaCO3(s) + 2 HCL(aq) -> CaCl2(aq) + CO2(g) + H2O(l) - H = -14.5 kJ - 25 g CaCO3 & 475 mL of .750 M HCL react. How much heat has released? - 25 g. CaCO3 x (1 mol/ 100 g) = .25 CaCO3 - (.475 L) x (.750 mol/L) = .356 mol HCL - .356 mol HCL x (14.5 kJ/2 mol HCL) = 2.58 kJ Kinetics - Rate law, order of reaction - Mechanisms & rate laws - Activation energy, Arrhenius equation - Kinetics vs. thermo Equilibrium - Idea of dynamic equilibrium, forward and back rates equal - Equilibrium constants, calculation of final amounts - Q vs. K - LeChatelier’s Principle Problem - C2H6(g) + 3 CO (g)  C5H6O3(g) - Put 5.63 g. C5H6O3 in a 2.5 L flask, heat to 200 C - At equilibrium, concentration of CO is 1.80 time concentration of C5H6O3

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- Find Keq for reaction - Keq = [C5H6O5]/[C2H6]*[CO]^3 - Make ice chart - [CO] = 1.8[C5H6O3] - 3x = 1.8(.01974-x) o 4.8x = 0.03533

x = .0074

- (0.01234)/(.0074)(.0222)^3 = 1.5 * 10^5

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