Chemistry 3: Mixtures and Solutions

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Chemistry 3: Mixtures & Solutions

ppt. by Robin D. Seamon

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Pure Substance: all of the particles are the same

Element: all the atoms are the same• Lots of the same atom

Compound: elements are the same and chemically combined- in a repeating pattern• Lots of the same molecule

mixture

Can be physically separated

compound

Chemically bound

element

Chemically bound

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S T I C K I N G T O G E T H E R :

• Cohesion- force that holds molecules of a material together

• Adhesion- force that holds different substances together

Water drop and water drop

Water drop and paper

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D I S S O L V I N G

• Water is a solvent- it dissolves solutes of solids, liquids & gases

• Solute- substance that dissolves• Solution- mixture of solvent and solute

http://www.chem4kids.com/files/matter_solution.html

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W A T E R• universal solvent- most substances will dissolve

in itWHY?

• Polar- have two areas that have opposite charges

negative near the oxygen b/c of unshared electrons

positive near hydrogens fully shared electrons

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S O L U T I O N SSolubility: ability of a solute to dissolve in a solvent at a certain temperature-Looks like a single substance; particles spread out evenly until the point of saturation

• Concentration: amount of solute dissolved in a solvent• Dilute: less solute• Concentrated: lots of solute

• Saturation: no more solute can be dissolved in the solvent

9Borax snowflakes or Rock candy

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M I X T U R E S

Combination of two or more substances that are NOT chemically combined• No chemical change• Can be separated

1. Filter: use a sieve to separate liquid from larger particles

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2. Evaporation: heat water; water evaporates, solute remains in the container

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3. Distillation: separates based upon boiling points (crude oil into gasoline & kerosene)

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4. Magnet: separates iron & aluminum

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5. Centrifuge: spinning machine separates parts of blood

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S U S P E N S I O N S

Suspension-Mixture in which particles of a material are dispersed throughout a liquid or gas but are large enough that they settle out

muddy water

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C O L L O I D

Colloid-mixture in which particles are dispersed throughout but are not heavy enough to settle out

milk, mayonaise, gelatin, whipped cream

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Pure Substance

Element Compound

Mixture

Homogeneous Mixture

Heterogeneous Mixture

Carbon COxygen O

Salt NaClSugar C H OWater H O

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2 12 22 11 Solution Alloy

SaltwaterNaCl + H O

Brass Cu + ZnBronze Cu + SnSteel Fe + C

SaladConglomerate

CLASSIFICATION OF MATTER

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