-
heterogeneous
contain more than one visible phase and are not uniform throughout
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homogeneous
also contain more than one kind of material and can be separated easily
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mixtures (solutions)
materials are so evenly distributed that the appear to be one phase
-
pure substances
always have the same somposition
-
2 types of pure substances
-
elements
contain only one kind of atom
-
compounds
contain more than one kind of atom
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phase
part of a material that has a uniform set of properties
-
interface
area where two phases meet
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physical properties
- can be observed or measured
- length
- mass
- shape
- color
- texture
- MP
- BP
- ductility
- density
- malleability
- solubility
- volume
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physical change
the identity of the substance is not changed after the conditions change
-
distillation
difference in boiling point
-
chemical property
explains how it reacts with another substance
-
Chemical change
- New substance is formed with new properties after conditions change
- color change
- gas given off
- change in temp
- precipitate forms
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Endothermic
energy absorbed, and the have a higher energy (cold)
-
exothermic
energy released, and the products have less energy (hot)
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activitaion energy
energy required to start the reaction
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What do you need to raise the temperature of water 1 degree?
4.184 j
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1 kilocalorie (C) =
1,000 calories (c)
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specific heat
the amount of heat needed to raise the temperature of one gram of a substance
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heat gained formula
q=m x T x Cp
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When the system loses heat, use
Ti-Tf
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When a substance gains heat, use
Tf-Ti
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