February 1st 2017 Chs 11 12 HW due Friday Ch 13 HW Tutoring Exam 1 next Wednesday Non programmable calculator Student ID Pencils Chapter 13 The Properties of Solutions The composition of a mixture can be variable and it retains some of the properties of its components Solution a homogeneous mixture exists as one phase Heterogeneous mixture two or more phases 13 1 Types of Solutions Intermolecular Forces and Solubility A solute dissolves in a solvent most abundant component to form a solution miscible soluble in any proportions The solubility S of a solute is the maximum amount that dissolves in a fixed quantity of solvent at a given temperature NaCl S 39 12 g 100 mL water at 100 C concentrated AgCl S 0 0021 g 100 mL water at 100 C dilute Substances that exhibit similar types of intermolecular force dissolve in each other like dissolves like Intermolecular Forces in Solution Hydration shell What is the principal intermolecular force in a solution of argon gas dissolved in water A Ion dipole B H bonding C Dipole dipole D Dispersion E Dipole induced dipole Liquid Solutions and the Role of Molecular Polarity When a solution forms solute solute attractions and solvent solvent attractions are replaced by solute solvent attractions This can only occur if the forces within the solute and solvent are similar to the forces that replace them Like dissolves Like Salts soluble in water Salts insoluble in hexane Liquid Solutions and the Role of Molecular Polarity Which pair of compounds will demonstrate the greatest solubility A CCl4 in water Nonpolar in polar immiscible B CH3CH2CH2CH2OH in water Long chain alcohol in polar low solubility C KCl in benzene C6H6 Salt in nonpolar solvent not soluble D CH3CH2OH in water Short chain alcohol in polar high solubility E CH3CH2OH in hexane Short chain alcohol in nonpolar low solubility 13 2 Why Substances Dissolve Understanding the Solution Process Heat of Solution Solution Cycles 1 Solute aggregated heat solute separated 2 Solvent aggregated heat solvent separated Hsolute 0 Hsolvent 0 3 Solute separated solvent separated solution heat Hmix 0 DHsoln DHsolute DHsolvent DHmix Heat of Solution Ionic Solids in Water DHsoln DHsolute DHsolvent DHmix DHhydration always 0 M g or X g H2O DHsolute DHlattice always 0 MX s M g X g DHsoln DHlattice DHhydration M aq or X aq Heat of Solution Ionic Solids in Water DHsoln DHlattice DHhydration of ions Use the following data to calculate the combined heat of hydration for the ions in sodium chloride NaCl Hlattice 787 3 kJ mol Hsoln 5 0 kJ mol A 792 3 kJ mol B 782 3 kJ mol C 5 0 kJ mol D 792 3 kJ mol E 787 3 kJ mol DH so ln DH lattice DH hydr of kJ kJ 5 0 787 3 DH hydr of mol mol kJ kJ DH hydr of ions 5 0 787 3 mol mol DH hydr of ions kJ 782 3 mol ions ions