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Ebook Chemistry (7th edition): Part 2

(BQ) Part 2 book "Chemistry" has contents: Chemical kinetics, chemical equilibrium; acids and bases; applications of aqueous equilibria; spontaneity, entropy, and free energy; electrochemistry; the nucleus - a chemist’s view; the representative elements: groups 1a through 4a; organic and biological molecules,.and other contents. | 12 Chemical Kinetics Contents 12.1 12.2 • 12.3 • 12.4 • • • • • 12.5 12.6 12.7 12.8 • • Reaction Rates Rate Laws: An Introduction Types of Rate Laws Determining the Form of the Rate Law Method of Initial Rates The Integrated Rate Law First-Order Rate Laws Half-Life of a First-Order Reaction Second-Order Rate Laws Zero-Order Rate Laws Integrated Rate Laws for Reactions with More Than One Reactant Rate Laws: A Summary Reaction Mechanisms A Model for Chemical Kinetics Catalysis Heterogeneous Catalysis Homogeneous Catalysis The kinetic energy of these world championship runners is evident in the 800-meter race at Saint-Denis, France. 526 T he applications of chemistry focus largely on chemical reactions, and the commercial use of a reaction requires knowledge of several of its characteristics, including its stoichiometry, energetics, and rate. A reaction is defined by its reactants and products, whose identity must be learned by experiment. Once the reactants and products are known, the equation for the reaction can be written and balanced, and stoichiometric calculations can be carried out. Another very important characteristic of a reaction is its spontaneity. Spontaneity refers to the inherent tendency for the process to occur; however, it implies nothing about speed. Spontaneous does not mean fast. There are many spontaneous reactions that are so slow that no apparent reaction occurs over a period of weeks or years at normal temperatures. For example, there is a strong inherent tendency for gaseous hydrogen and oxygen to combine, that is, 2H2 1g2 ϩ O2 1g2 ¡ 2H2O1l2 but in fact the two gases can coexist indefinitely at 25°C. Similarly, the gaseous reactions H2 1g2 ϩ Cl2 1g2 ¡ 2HCl1g2 N2 1g2 ϩ 3H2 1g2 ¡ 2NH3 1g2 Visualization: Coffee Creamer Flammability are both highly likely to occur from a thermodynamic standpoint, but we observe no reactions under normal conditions. In addition, the process of changing diamond to graphite is spontaneous but is so slow that .