4.6 Acids and Bases: General Principles FIGURE 4.5 Hydrogen bonding between molecules 8 CH3(CH2)6CH,F CH3(CH2)CH,CI CH3 (CH2).CH, Br CH3(CH2)CH, Density 0.80g/mL 0. 89 g/mL 1.12g/mL 34 g/mL Because alkyl halides are insoluble in water, a mixture of an alkyl halide and water sep arates into two layers. When the alkyl halide is a fluoride or chloride, it is the upper layer and water is the lower. The situation is reversed when the alkyl halide is a bro- mide or an iodide. In these cases the alkyl halide is the lower layer. Polyhalogenation increases the density. The compounds CH_Cl2, CHCl3, and CCl4, for example, are all more dense than water All liquid alcohols have densities of approximately 0.8 g/mL and are, therefore, less dense than water 4.6 ACIDS AND BASES: GENERAL PRINCIPLES A solid understanding of acid-base chemistry is a big help in understanding chemical reactivity. This and the next section review some principles and properties of acids and bases and examine how these principles apply to alcohols According to the theory proposed by Svante Arrhenius, a Swedish chemist and winner of the 1903 Nobel Prize in chemistry, an acid ionizes in aqueous solution to lib Rre protons(H, hydrogen ions), whereas bases ionize to liberate hydroxide ions lO). A more general theory of acids and bases was devised independently by Johannes Bronsted(Denmark) and Thomas M. Lowry(England) in 1923. In the Bronsted-Lowry approach, an acid is a proton donor, and a base is a proton acceptor. B/+HA、-H used to show the electron air of the base abstracting a m the acid. The Base Acid of electrons in the h-a air in the arrows track electron ment, not atomic movement. Back Forward Main Menu Study Guide ToC Student OLC MHHE WebsiteBecause alkyl halides are insoluble in water, a mixture of an alkyl halide and water sep￾arates into two layers. When the alkyl halide is a fluoride or chloride, it is the upper layer and water is the lower. The situation is reversed when the alkyl halide is a bro￾mide or an iodide. In these cases the alkyl halide is the lower layer. Polyhalogenation increases the density. The compounds CH2Cl2, CHCl3, and CCl4, for example, are all more dense than water. All liquid alcohols have densities of approximately 0.8 g/mL and are, therefore, less dense than water. 4.6 ACIDS AND BASES: GENERAL PRINCIPLES A solid understanding of acid–base chemistry is a big help in understanding chemical reactivity. This and the next section review some principles and properties of acids and bases and examine how these principles apply to alcohols. According to the theory proposed by Svante Arrhenius, a Swedish chemist and winner of the 1903 Nobel Prize in chemistry, an acid ionizes in aqueous solution to lib￾erate protons (H, hydrogen ions), whereas bases ionize to liberate hydroxide ions (HO). A more general theory of acids and bases was devised independently by Johannes Brønsted (Denmark) and Thomas M. Lowry (England) in 1923. In the Brønsted–Lowry approach, an acid is a proton donor, and a base is a proton acceptor. B Base B H Conjugate acid A Conjugate base Acid H A 4.6 Acids and Bases: General Principles 133 0.89 g/mL CH3(CH2)6CH2Cl 1.12 g/mL CH3(CH2)6CH2Br 1.34 g/mL CH3(CH2)6CH2I 0.80 g/mL CH3(CH2)6CH2F Density (20°C): FIGURE 4.5 Hydrogen bonding between molecules of ethanol and water. Curved arrow notation is used to show the electron pair of the base abstracting a proton from the acid. The pair of electrons in the H±A bond becomes an unshared pair in the anion :A. Curved arrows track electron move￾ment, not atomic movement. Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website