MIXTURES & SOLUTIONS 1

Mixtures Variable combination of 2 or more pure substances. Heterogeneous Homogeneous

HETEROGENEOUS MIXTURES 3

Heterogeneous Mixtures medium-large particles exhibits Tyndall effect particles may settle example: milk, lemonade

Suspensions Suspensions are NOT solutions; they are heterogeneous mixtures. The particles are so large that they settle out of the solvent if not constantly stirred. They can be separated by filtration.

Colloids Colloids are NOT solutions; they are heterogeneous mixtures. The particles are intermediate in size between those of a suspension and those of a solution. They are made up of a dispersed phase and a dispersing medium. They cannot be separated by filtration- particles will not settle out. 6

The Tyndall Effect Colloids scatter light, making a beam visible. Solutions do not scatter light. Which glass contains a colloid? colloid solution 7

Types of Colloids Examples Dispersing Medium Dispersed Substance Colloid Type Fog, aerosol sprays Gas Liquid Aerosol Smoke, airborne bacteria Solid Whipped cream, soap suds Foam Milk, mayonnaise Emulsion Paint, clays, gelatin Sol Marshmallow, Styrofoam Solid foam Butter, cheese Solid emulsion Ruby glass Solid sol

SEPARATING MIXTURES 9

Separating Mixtures Filtration Distillation

Separating Mixtures Crystallization Chromatography

HOMOGENEOUS MIXTURES 12

Solutions Homogeneous mixtures TWO or more substances in a single phase Has the same composition and properties throughout Very small particles Dissolved atoms, ions, or molecules 13

Properties of Solutions Usually clear and transparent-not necessarily colorless No Tyndall effect Particles do not settle over time Can not be separated by filtration Can be solids, liquids, or gases 14

Alloys: mixture made of 2 or more metals- a solid solution Ex. Steel, brass (Cu and Zn), bronze, 14-karat gold, sterling silver BRONZE KARATS of GOLD STEEL BRASS 15

Solute Solvent A solute is the dissolved substance in a solution. Salt in salt water Sugar in soda drinks Carbon dioxide in soda drinks Solvent A solvent is the dissolving medium in a solution. Water in salt water Water in soda

Terms to Know Soluble vs. Insoluble Miscible vs. Immiscible Solvation & Hydration Electrolyte vs. Nonelectrolyte

Solution Types Saturated Unsaturated Supersaturated

POGIL Time!

Factors affecting the RATE of solvation: Temperature of the solvent … ↑temperature, ↑rate Stirring/agitation … ↑solute/solvent contact, ↑ rate Size of the solute particles … ↑surface area, ↑ rate Amount of solute already in solution …increase solute, ↓ rate 20

Solubility - The amount of a substance required to form a saturated solution with a specific amount of solvent at a specified temperature and pressure.

Solute/Solvent Interactions General Rule : “like dissolves like” Polar solutes dissolve in polar solvents Non-polar solutes dissolve in non-polar solvents

Temperature and Solubility 1. Gas solubility decreases with increases in temperature. 2. Solubility of MOST solids increases with temperature. 23

Pressure and Solubility Solid/Liquid: very little effect Gas: ↑P…↑solubility …obeys Henry’s Law 24

Pressure and Solubility Gas: ↓P… ↓solubility …Effervescence 25

POGIL Time!

Solution Concentration The concentration of a solution is a measure of how much solute is dissolved in a specific amount of solvent or solution. 27

Molarity Molarity (M): moles of solute per liter solution Referred to as Molar...ex. 5.5 M NaCl 28

Dilutions Stock solutions are concentrated with standard molarities can be diluted by adding solvent ↑ solvent particles… ↓ solution concentration number of solute particles is UNchanged 29