tailieunhanh - Ebook General chemistry - The essential concepts (6th edition): Part 2

(BQ) Part 2 book "General chemistry - The essential concepts" has contents: Energy relationships in chemical reactions; the electronic structure of atoms; the periodic table; introduction to organic chemistry; intermolecular forces and liquids and solids; intermolecular forces and liquids and solids; chemical kinetics; chemical kinetics,. and other contents. | Page 176 10/24/09 4:26:28 PM user-s180 /Volumes/MHDQ-New/MHDQ144/MHDQ144-06 CHAPTER 6 Energy Relationships in Chemical Reactions Explosives such as dynamite and TNT undergo decomposition when detonated and release heat in exothermic reactions. CHAPTER OUTLINE ESSENTIAL CONCEPTS Energy The many different forms of energy are, at least in principle, interconvertible. First Law of Thermodynamics The first law of thermodynamics, which is based on the law of conservation of energy, relates the internal energy change of a system to the heat change and the work done. It can also be expressed to show the relationship between the internal energy change and enthalpy change of a process. Thermochemistry Most chemical reactions involve the absorption or release of heat. At constant pressure, the heat change is equal to the enthalpy change. The heat change is measured by a calorimeter. Constant-pressure and constant-volume calorimeters are devices for measuring heat changes under the stated conditions. Standard Enthalpy of Reaction Standard enthalpy of reaction is the enthalpy change when the reaction is carried out at 1 atm pressure. It can be calculated from the standard enthalpies of formation of reactants and products. Hess’s law enables us to measure the standard enthalpy of formation of a compound in an indirect way. The Nature of Energy and Types of Energy 177 Energy Changes in Chemical Reactions 178 Introduction to Thermodynamics 179 The First Law of Thermodynamics • Work and Heat Enthalpy of Chemical Reactions 185 Enthalpy • Enthalpy of Reactions • Thermochemical Equations • A Comparison of DH and DU Calorimetry 191 Specific Heat and Heat Capacity • Constant-Volume Calorimetry • Constant-Pressure Calorimetry Standard Enthalpy of Formation and Reaction 196 The Direct Method • The Indirect Method STUDENT INTERACTIVE ACTIVITIES Animations Heat Flow () Electronic Homework Example Practice Problems End of Chapter Problems