Types of Mixtures The saga continues….

Mixtures Combination of more than one pure substance but not bonded chemically Can be separated physically or chemically! Salads, Kool-Aid, Pizza.

Types of Mixtures: Homogeneous “Homogeneous” means: appears the same throughout. Kool Aid contains water, sugar & coloring, but is not a pure substance because each of the ingredients can vary each time it is made. It is a homogeneous mixture because it is the same throughout and can be separated! We say they are “miscible” (they dissolve completely).

Types of Mixtures: Heterogeneous “Heterogeneous” Mixture: Mixtures in which differences can be seen easily…oil & water, sand & water, flour & water.

Mixtures also come in Different Forms There are THREE Forms of mixtures: Solutions Suspensions Colloids

Solutions A solution is a mixture that appears to be a single substance, but it is actually composed of 2 or more substances that are distributed evenly amongst each other. SOLUTIONS ARE HOMOGENEOUS carbon dioxide is dissolved in water sugar & Kool-Aid powder are dissolved in water salt is dissolved in water

Suspensions A suspension is a mixture in which particles of a material are dispersed throughout a liquid or gas, but are large enough that they settle out. SUSPENSIONS ARE HETEROGENEOUS Snow globe muddy water Italian dressing

Colloids A colloid is a mixture in which the particles are dispersed throughout but are not heavy enough to settle out. COLLOIDS ARE HOMOGENEOUS Colloids have properties of both solutions & suspensions. milk mayonnaise

Separating Mixtures Substances in a mixture are physically combined, so processes bases on differences in physical properties are used to separate component Numerous techniques have been developed to separate mixtures to study components

Filtration Sieving Dissolving Centrifuging Evaporating Distillation Magnet

Filtration Used to separate heterogeneous mixtures composed of solids and liquids Uses a porous barrier to separate the solid from the liquid Liquid passes through leaving the solid in the filter paper

Sieving a porous material is used to separate particles of different sizes. method is most commonly used to effect gross separations, as of liquids from suspended crystals or other solids.

Dissolving Used to separate two solids when one is soluble in water and the other is not Put the solids in a solvent(water) and then use a filter to separate the insoluable solid

Evaporation Evaporation can be used to separate a solute from the solvent in a solution Review the terms; solution, solute and solvent.

Distillation Used to separate homogeneous mixtures Based on differences in boiling points of substances involved

Centrifuges rotate containers of liquids to separate suspended materials with different densities. Centrifuges separate different components of human blood or milk and to clarify solutions. A high speed separator can rotate at great speed to separate fat (cream) from milk. The spin drier in washing machines is a type of centrifuge that throws out the liquid by the "centrifugal force" of the rotation.

A magnet Can be used to separate a magnetic substance from a non-magnetic substance Magnets are used in the re-cycling industry to separate ferrous and non ferrous metals.

What is it? Cheerios

Homogeneous

What is it? Trail Mix

Heterogeneous

What is it? Kool - Aid

Homogeneous

What is it? Italian Salad Dressing

Heterogeneous

Try these……….. Raisin Bran

Orange Juice

Air

Cake Batter