I. The Nature of Solutions Solutions

A. Definitions  Solution - homogeneous mixture Solvent - present in greater amount Solute - substance being dissolved

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

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

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

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

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)

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

B. Solvation NONPOLAR POLAR “Like Dissolves Like”

“like dissolves like”  rule used to determine if substance will dissolve in another  based on attractive forces between solute and solvent

“like dissolves like”  polar solvents – dissolve polar molecular compounds and ionic compounds ex: salt and water, alcohol and vinegar  nonpolar solvents – dissolve nonpolar compounds ex: oil and gasoline

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

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. Solubility  Solubility Curve –shows the dependence of solubility on temperature

C. Solubility  Solids are more soluble at... –high temperatures.  Gases are more soluble at... –low temperatures & high pressures EX: soda