TOPIC: Intro Solutions and Solubility Do Now: check out test grades

Classification of Matter Pure Substances Mixtures Homogeneous Heterogeneous Elements Compounds VIDEO

Solution Homogenous Mixture (aka SOLUTION): particles too small to see Particles evenly distributed Particles do not settle -translucent – looks clear

Parts of a Solution Solute = dissolved substance Solvent = dispersing medium (often water)

Solubility = the max amount of solute that can be dissolved in a solvent Many solids and gases dissolve in water As you increase the temperature, you can dissolve more solid Does this work the same with gas? To get gases dissolve, decrease temperature and increase pressure

Not everything dissolves in water Likes dissolve Likes Water is polar, so only polar things will dissolve in water Things that dissolve in water Soluble ionic compounds Acids (ex HCl) Bases (ex. NaOH) Polar covalent molecules

Dissolving an Ionic Substance in a Water We say it IONIZES (separates into ions) Example: NaCl(s)  Na+(aq) + Cl-(aq) CaCl2(s)  Ca2+(aq) + 2Cl-(aq) AlCl3(s)  Al3+(aq) + 3Cl-(aq) The ions are spread out among the water molecules.

Dissolving a Covalent Substance in water stays as molecules Ex: sucrose C12H22O11(s)  C12H22O11(aq) The sugar molecules are spread out among the water molecules.

Not everything dissolves in water Water is often used as a solvent Not everything dissolves in water Soluble = dissolves in water = aq Insoluble = doesn’t dissolve in water Miscible = 2 liquids that dissolve Immiscible = 2 liquids that don’t dissolve

Summary: Factors Affecting Solubility Nature of the solvent and the solute: LIKE DISSOLVES LIKE Temperature Pressure (for systems with gases)