vi the information collected and discussed in this volume may help toward the achievement of such an objective. I should like to express my debt of gratitude to the authors who have contributed to this volume. Editing a work of this nature can strain long­ established personal relationships and I thank my various colleagues for bearing with me and responding (sooner or later) to one or several letters or telephone calls. My special thanks once again go to Mrs. Joyce Johnson, who bore the main brunt of this seemingly endless correspondence and without whose help the editorial and referencing work would have taken several years. F. FRANKS Biophysics Division Unilever Research Laboratory Colworth/ Welwyn Colworth House, Sharnbrook, Bedford January, 1973 Contents Contents of Volume 1 ............................. . . . . . .. . . .. xv Contents of Volume 3 ........................ '. . . . . . . . . . . . xvi . . . . Contents of Volume 4 . . . . . . . . . . . . . . . . . . . . . . . . .. . . . xvii . . . . . . . . . . . Chapter 1 The Solvent Properties of Water F. Franks 1. Water, the Universal Solvent-the Study of Aqueous Solutions 2. Aqueous Solutions of Nonelectrolytes ................. . 5 2.1. Apolar Solutes ................................. . 6 2.2. Polar Solutes .................................. . 19 2.3. Ionic Solutes Containing Alkyl Residues-"Apolar Electrolytes" ................................... . 38 3. Aqueous Solutions of Electrolytes .................... . 42 3.1. Single Ion Properties ............................ . 42 3.2. Ion-Water Interactions ......................... . 43 3.3. Interionic Effects ............................... . 47 4. Complex Aqueous Mixtures 48 Chapter 2 Water in Stoichiometric Hydrates M. Falk and O. Knop 1. Introduction. . . . . .. . . . . . . . . . . . . . . . . . . . . . . 55 . . . . . . . . . . . . . 2. Symmetry and Types of Environment of the H0 Molecule 2 in Crystals .......................................... 57 vii Contents viii 2.1. Site Symmetry. . . . . . . . . . . . . . . . . . . . . . . . . 57 . . . . . . . . . .