Classification of matter

Cla s s ific a tio n o f Ma tte r

Theoretical Chemistry

Ma te ria lsSpecific types of matterDescribed according to phase (solid, liquid, gas)

Pure Subs ta nc e sContain only one type of matterCannot be separated physically

Pure Subs ta nc e sElements - simplest pure substances made of only one type of atom (Periodic Table)

Pure Subs ta nc e sCompounds - – two or more elements chemically combined (H2O, CuSO4)

Mixture sPhysical combination of two or more substancesCan be separated physically

He te ro g e ne o us Mix ture sSubstances can be easily distinguished and separatedEx: sand and salt, iron and sugar, sand and gravel

Ho m o g e ne o us Mix ture sSubstances are well mixed and appear the same throughoutEx: Solution

So lutio nsSolute dissolves in solvent to form solution.Concentrated solution contains more solute than dilute solution.Ex: Kool-Aid, iced tea, coffee

Exte ns ive Pro p e rtie sDepend on sample sizeSpecific to a single objectEx: length, mass, diameter

Inte ns ive Pro p e rtie sDo not depend on sample sizeUsed to identify types of matterAll physical and chemical properties are intensive

Phys ic a l Pro p e rtie sDescribe substances undergoing physical changesEx: density, color, texture, conductivity, malleability, ductility, boiling point, melting point

Che m ic a l Pro p e rtie sDescribe substances undergoing chemical changesEx: flammability, corrosiveness, volatility

Phys ic a l Cha ng e sSame substance remains after changeUsed to separate mixturesEx: pounding, tearing, cutting, dissolving, evaporating, melting, boiling, pulling

Che m ic a l Cha ng e sResults in new substance with new propertiesAlso known as a chemical reactionEx: burning, digesting, fermenting, decomposing

Che m ic a l Cha ng e Evid e nc e1. Precipitate forms (solid)2. Gas evolves (bubbles)3. Color change4. Energy change

• Exothermic = releases energy• Endothermic = absorbs energy

5. Odor produced (sometimes)

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