Ways of expressing concentration, the solution process, factors affecting solubility, colligative properties,. is the main content of the lecture "Chapter 13: Properties of solutions". Invite you to consult the detailed content lectures to capture details. | Copyright 1999, PRENTICE HALL Chapter 13 Properties of Solutions Chapter 13 David P. White University of North Carolina, Wilmington 1 1 1 1 Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process A solution is a homogeneous mixture of solute (present in smallest amount) and solvent (present in largest amount). Solutes and solvent are components of the solution. In the process of making solutions with condensed phases, intermolecular forces become rearranged. Consider NaCl (solute) dissolving in water (solvent): the water H-bonds have to be interrupted, NaCl dissociates into Na+ and Cl-, ion-dipole forces form: Na+ -OH2 and Cl- +H2O. We say the ions are solvated by water. If water is the solvent, we say the ions are hydrated. Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process Energy Changes and Solution Formation There are three energy steps in forming a solution: separation of . | Copyright 1999, PRENTICE HALL Chapter 13 Properties of Solutions Chapter 13 David P. White University of North Carolina, Wilmington 1 1 1 1 Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process A solution is a homogeneous mixture of solute (present in smallest amount) and solvent (present in largest amount). Solutes and solvent are components of the solution. In the process of making solutions with condensed phases, intermolecular forces become rearranged. Consider NaCl (solute) dissolving in water (solvent): the water H-bonds have to be interrupted, NaCl dissociates into Na+ and Cl-, ion-dipole forces form: Na+ -OH2 and Cl- +H2O. We say the ions are solvated by water. If water is the solvent, we say the ions are hydrated. Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process Energy Changes and Solution Formation There are three energy steps in forming a solution: separation of solute molecules ( H1), separation of solvent molecules ( H2), and formation of solute-solvent interactions ( H3). We define the enthalpy change in the solution process as Hsoln = H1 + H2 + H3. Hsoln can either be positive or negative depending on the intermolecular forces. Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process Energy Changes and Solution Formation Copyright 1999, PRENTICE HALL Chapter 13 The Solution Process Energy Changes and Solution Formation Breaking attractive intermolecular forces is always endothermic. Forming attractive intermolecular forces is always exothermic. To determine whether Hsoln is positive or negative, we consider the strengths of all solute-solute and solute-solvent interactions: H1 and H2 are both positive. H3 is always negative. It is possible to have either H3 > ( H1 + H2) or H3 The Solution Process Energy Changes and Solution Formation Copyright 1999, PRENTICE .