Chemistry

Chemistry 1210: Introduction to General Chemistry Dr. Gina M. Florio 15 Nov. 2012 Jespersen, Brady, Hyslop Chapter 9 Chemical Bonding: General Concepts Ionic Bonds Ch. 9.2 Ionic bonds are the attraction between positive and negative ions in an ionic compound. e.g. NaCl An electron is transferred from the metal (Na) to the nonmetal (Cl): Ionic compounds form when metals and nonmetals react and they are held together by ionic bonds. Compounds (ionic and molecular) are formed due to a decrease (lowering) of the potential energy of system. Net energy change associated with the electron transfer reaction. So, why does NaCl (s) form at all? 2 Lattice Energy of Ionic Compounds Ch. 9.2 The energy needed to produce separated gaseous ions from one mole of the solid is the lattice energy:

Chemistry 1210: Introduction to General Chemistry Dr. Gina M. Florio 18 October 2012 Brady, Jespersen, Hyslop Chapter 7 Energy & Chemical Change Thermochemistry: the study of energy flow during a chemical reaction Ch. 7.1 Energy: the ability to do work; often measured as heat Kinetic Energy: the energy of motion; KE = ?mv2 Potential Energy: stored or positional energy; chemical energy (no simple eqn.) Conservation of Energy: 1. Energy cannot be created or destroyed 2. Energy is only converted from one form to another (KE ? PE) 3. Total energy of the universe (or an isolated system) is constant Thermochemistry: Basic Definitions Units of Energy 1 Joule (J) ? the KE possessed by a 2 kg object moving at a velocity of 1 m/s 1 cal = 4.184 J (exactly) 1 kcal = 4.184 kJ

Chemistry 1210: Introduction to General Chemistry Dr. Gina M. Florio 27 Sept. 2012 Jespersen, Brady, Hyslop Chapter 5B Molecular View of Reactions in Aqueous Solution Properties of Solutions: Quantitative Composition The molar concentration or molarity (M) is defined as: units of M = mol/L (mol L-1) Example: How many grams of AgNO3 are needed to prepare 250 mL of a 0.0125 M AgNO3 solution? NOTE: You can also solve this for concentration OR liters of solution CH. 5 Properties of Solutions: Quantitative Composition Solutions of high concentration can be diluted to make solutions of lower concentration. Dilution: CH. 5 Example: How much 1.0 M CuSO4 (aq) solution is required to prepare 250 mL of a 0.10 M CuSO4 (aq) solution? How much water is required? Solution Stoichiometry CH. 5

Chemistry 1210: General Chemistry Dr. Gina M. Florio 13 September 2012 Jespersen, Brady, Hyslop, Chapter 4 The Mole and Stoichiometry CHE 1210 Lecture Slides G.M. Florio 1 Conversion Factors Conversion Factor ? relates one quantity to another ? used to convert between two units in chemistry What is my height in centimeters (cm) if I am 5 feet 4 inches tall? 1. How many inches are in a foot? 2. How many inches are in a centimeter? 12 inches = 1 foot 1 inch = 2.54 cm Factor Label Method The factor-label method, or dimensional analysis lets us treat a numerical problem as one involving a conversion from one kind of units to another using conversion factors.