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Substances have a fixed composition
Elements and Compounds are pure substances
• Elements can’t be broken down to simpler substances
• Compounds are difficult to break down to simpler
substances-separated through chemical reactions
Mixtures and Solutions are not pure substances and
can be easily separated without chemical reactions
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Color, shape, size, density, melting point,
boiling point
Appearance and behavior
Think of appearance as being descriptive
Behavior is like magnetism or being ductile or
malleable
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The identity of the substance does not
change
Changing the state of matter does not change
the chemical make up of the substance
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The identity of the substance changes
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New substance(s) formed
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Extensive properties depend on how much of
a substance is present-size, weight, mass,
volume
Intensive properties do not depend on how
much of substance is present-color, density,
odor, luster, ductility, malleability, hardness,
conductivity, boiling point, melting/freezing
point
Silver Nitrate and Copper-Single replacement
reaction
Cu + Ag(NO3)2 → Cu(NO3)2 + Ag
One element replaces another in a compound
Silver precipitate and copper nitrate produced
2HCl + Zn → ZnCl2 + H2
Single replacement reaction
Hydrogen gas produced
Zinc replaces hydrogen
Temp change
Exothermic-feels hot but the reaction is
actually losing heat
CuSO4 + Fe → FeSO4 + Cu
Single replacement reaction
Solidifies
Iron replaces copper
Temp change
Exothermic-feels hot but the reaction is
actually losing heat
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Decomposition reaction
2H2O2 → 2H2O + O2
Exothermic
Gas is released
Liquid and yeast remain
What is yeast’s role in the reaction?
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CH3COOH + NaH3CO3 → CO2 + H2O + CH3OONa
Gas is released
Na actually separates and is dissolved
Feels cold which would mean endothermic but it
really isn’t-CO2 cools rapidly causing the cold
Not a chemical reaction
 Chromatography
 Solid black ink separated into blue/brown/yellow
so it is a solution
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Sugar simply dissolves in the water
 Sugar does not become something new, still a
solid just mixes between the water particles
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Ground in to a powder
Still chalk, still solid