topic: intro solutions and solubility do now: check out test grades

TOPIC: Intro Solutions and Solubility

Do Now: check out test grades

Classification of Matter

Matter

PureSubstances Mixtures

HomogeneousMixtures

HeterogeneousMixturesElements 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 WaterWe 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 waterstays as molecules

• Ex: sucrose• C12H22O11(s) C12H22O11(aq)• The sugar molecules are spread out

among the water molecules.

Water is often used as a solvent

• Soluble = dissolves in water = aq• Insoluble = doesn’t dissolve in water• Miscible = 2 liquids that dissolve• Immiscible = 2 liquids that don’t dissolve

Not everything dissolves in water

Summary: Factors Affecting Solubility

• Nature of the solvent and the solute:LIKE DISSOLVES LIKE

• Temperature

• Pressure (for systems with gases)