II III I C. Johannesson I. The Nature of Solutions (p , ) Ch. 13 & 14 - Solutions

C. Johannesson A. Definitions  Solution -  Solution - homogeneous mixture of two or more components Solvent Solvent - present in greater amount Solute Solute - substance being dissolved

C. Johannesson A. Definitions Solute Solute - KMnO 4 Solvent Solvent - H 2 O

C. Johannesson B. Solvation  Solvation –  Solvation – the process of dissolving solute particles are separated and pulled into solution solute particles are surrounded by solvent particles

C. Johannesson B. Solvation Strong Electrolyte Non- Electrolyte solute exists as ions only - + salt - + sugar solute exists as molecules only - + acetic acid Weak Electrolyte solute exists as ions and molecules DISSOCIATIONIONIZATION View animation online.animation

C. Johannesson B. Solvation  Dissociation separation of an ionic solid into aqueous ions NaCl(s)  Na + (aq) + Cl – (aq)

C. Johannesson B. Solvation  Ionization breaking apart of some polar molecules into aqueous ions HNO 3 (aq) + H 2 O(l)  H 3 O + (aq) + NO 3 – (aq)

C. Johannesson B. Solvation  Molecular Solvation molecules stay intact C 6 H 12 O 6 (s)  C 6 H 12 O 6 (aq)

C. Johannesson B. Solvation NONPOLAR POLAR “Like Dissolves Like”

C. Johannesson B. Solvation  Soap/Detergent polar “head” with long nonpolar “tail” dissolves nonpolar grease in polar water

Suspensions  The particles in suspensions are larger than those found in solutions.  Components of a suspension can be evenly distributed by a mechanical means, like by shaking the contents, but the components will settle out.  These are HETEROGENOUS mixtures

Suspensions Flour suspended in water Sand settling out of water

Colloidal Suspensions  Particles intermediate in size between those found in solutions and suspensions can be mixed such that they remain evenly distributed without settling out.  The mixture they form is called a colloidal dispersion.

Colloidal Examples milk paint Jell-O

C. Johannesson C. Solubility SATURATED SOLUTION no more solute dissolves UNSATURATED SOLUTION more solute dissolves SUPERSATURATED SOLUTION becomes unstable, crystals form concentration

C. Johannesson C. Solubility  Solubility maximum grams of solute that will dissolve in 100 g of solvent at a given temperature varies with temp based on a saturated soln

C. Johannesson C. Solubility  Solubility Curve shows the dependence of solubility on temperature

C. Johannesson C. Solubility  Solids are more soluble at... high temperatures.  Gases are more soluble at... low temperatures & high pressures (Henry’s Law). EX: nitrogen narcosis, the “bends,” soda