AP Chemistry A. Allan Chapter 4 Notes - Types of Chemical Reactions and Solution Chemistry 4.1 Water, the Common Solvent A. Structure of water 1. Oxygen's electronegativity is high (3.5) and hydrogen's is low (2.1) 2. Water is a bent molecule 3. Water is a polar molecule B. Hydration of Ionic Solute Molecules 1. Positive ions attracted to the oxygen end of water 2. Negative ions attracted to the hydrogen end of water C. Hydration of Polar Solute Molecules 1. Negative end of polar solute molecules are attracted to water's hydrogen 2. Positive end of polar solute molecules are attracted to water's oxygen D. "Like Dissolves Like" 1. Polar and ionic compounds dissolve in polar solvents like water 2. Nonpolar compounds like fats dissolve in nonpolar solvents like ____ ?_____