Fall Final Exam

Wavelength/Frequency Calculations Given on formula sheet E=hv and c=λv Know relationship between wavelength, frequency, and energy Ex: longer wavelength means lower energy Practice: Two waves of light have different frequencies: 34 hertz and 74 hertz. Which has more energy? Which has a shorter wavelength?

Hybridization Know the shapes and bonds that correspond to: Practice: Give the hybridization of each carbon atom. Label all sigma and pi bonds.

Lewis Structures Count electrons Check structure and octet rule Move electrons into multiple bonds if needed Check formal charge Include brackets and charge for ions Practice: N2, CO32-

Periodic Trends Know the trends for Ionization energy Electronegativity Atomic size Ionic size Know the reasons for trends in terms of Coulombic attraction (between outer electrons and nucleus) Remember the variables of coulombs law are radius (distance between charges) & magnitude of charge Effective nuclear charge (“actual” charge felt by outer electrons; protons-inner electrons= Zeff) Atoms in the same group have the same Zeff so their trends are best explained using Coulomb’s Law Practice: Which has a greater electronegativity: Ca or Ba? Which has a smaller ionization energy: Al or S? Also, be able to explain why there are exceptions when given.

Types of Solids Know Ionic solids Molecular solids Nonbonding solids Metallic solids Network covalent solids Practice: Describe each type of solid: a) Ne, b) quartz, c) water, d) calcium chloride

Photoelectron Spectrums Be able to identify electron configurations from PES spectra Height of peak corresponds to number of electrons Location of peak corresponds to energy level Sketch a PES spectrum for silicon

Intermolecular Forces Know Ionic/Covalent/metallic London Dispersion Dipole-Dipole Hydrogen Bonding Ion-dipole Practice: List all the IM forces in a) cesium, b) ammonia, c) methane, d) carbon tetrachloride

Energy Calculations Know when to use Q=mcΔT or Q=Hm Describe energy flow for reactions, solutions, or phase changes Know that all systems adjust until they reach “thermal equilibrium”

General Skills that you should be an EXPERT in Stoichiometry Dimensional Analysis Periodic Table Charges of ions Symbols Metal/non-metal Transition metals, halogens, alkali metals, etc. Manipulating algebraic equations Molar relationships (in a reaction, compound, etc.) Understand that all processes tend toward lower potential energy (bonding, solutions, reactions)

General Advice When in doubt… Highlight variables Look at equations sheet for possible relationships, constants, etc. Always focus on the WHY Ask yourself, does my answer make sense??? If you know the relationship between two variables, make sure your answer aligns with that relationship Sometimes the answer isn’t the only explanation, but it’s always the best explanation