Chemistry

Chemistry 1210: General Chemistry Dr. Gina M. Florio 06 September 2012 Lecture Notes Jespersen, Brady, Hyslop, CH 3 Elements, Compounds, and the Periodic Table Structure of the Atom Atom consists of smaller (subatomic) particles: Protons (positively charged) Neutrons (no charge) Electrons (negatively charged) Found in the atomic nucleus e ?1 0 Electrons H+ 1 1 p 1 1 , Protons and n 0 1 Neutrons Matter is typically neutral ? equal number protons and electrons per atom Size: If diameter of nucleus = 1 foot, then diameter of atom ~ 1.9 miles! Ch. 3.1 2 Chapter 1.6 Identification of Atoms Each atom has two ID numbers: 1. Atomic Number (Z) Z = Number of protons Element ? a substance whose atoms contain the same number of protons ? a substance with a unique atomic number, Z Isotope

Kinetic Theory Of Gases Postulates of the Kinetic Theory of Gases: A gas consists of a large number of tiny particles that are in constant, random motion The gas particles occupy a net volume so small in relation to the volume of their container that their contribution to the total volume can be ignored The collisions between particles and the walls of the container are perfectly elastic (no energy transfer) Kinetic Theory of Gases relates temperature to average kinetic energy Kinetic Theory of Gases (aka Kinetic Molecular Theory) can be used to explain the Gas Laws: Pressure-Volume Relationship (Boyle?s Law) P? 1/V or V ? 1/P (at constant n, T) Pressure-Temperature Relationship (Guy-Lussac?s Law) ?T, ?v ?v, ?P Volume-Temperature Relationship (Charles?s Law)

Chemistry 1210: Introduction to General Chemistry Dr. Gina M. Florio 06 Dec. 2012 Brady, Jespersen, & Hyslop Chapter 11 Properties of Gases Properties of Gases Compressible Low Density Exert Pressure (temperature dependence) Expand Mixable Some common properties of gases: While bulk properties, these intimate a molecular level foundation. Properties of Gases Recall that our understanding of kinetic energy in molecular systems relies on a molecular-level picture of gases. Kinetic Theory of Gases (CH 7) Example: Pressure Units of Pressure Standard atmosphere (atm): the pressure needed to support a column of mercury 760 mm high measures at 0 ?C The SI unit of pressure is the pascal (Pa): Pressure Measurements Open-ended Mercury Manometer: