35 terms

Chemistry Chapter 3: Properties of Matter and Energy

Chemistry Chapter 3: Properties of Matter and Energy
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physical properties
properties that can be observed or measured without changing the substance into another substance
physical state
solid, liquid, or gas
solid
composed of matter whose particles are close together and are relatively fixed in position (definite shape and definite volume)
liquid
particles are close together, but they are able to move past each other (indefinite shape and definite volume)
gas
atoms or molecules that are not close to one another and move independently and in random motion (indefinite volume and indefinite shape)
melting point
the temperature at which a particular element or compound changes from the solid state to the liquid state
freezing point
the temperature at which a particular element or compound changes from the liquid state to the solid state
boiling point
the temperature at which boiling begins
boiling
the point at which gas bubbles begin to escape from liquid
condensation
change from gas to liquid
physical change
does not involve a change in the composition of the substance but is simply a change in physical state or dimensions
intensive properties
(clarity, color, density) properties whose value does not depend on the amount of material present
extensive properties
(mass, volume) properties whose value does depend on the amount of material present
chemical properties
the tendency of a pure substance to undergo chemical changes
chemical changes
transforming one substance into one or more other substances
Law of Conservation of Mass
States that matter is neither created or destroyed in a chemical reaction, it just changes form
density
ratio of mass to volume at a given temperature
density of a pure substance
constant property that can be used to identify the substance
specific gravity
related to density, the ratio of the mass of a substance to the mass of an equal volume of water under the same conditions (density of a substance/density of water)
heterogeneous mixture
a non-uniform mixture containing two or more phases with definite bounderies between the phases
phase
one physical state with distinct bounderies and uniform properties
homogeneous mixture
a mixture is the same throughout and contains only one phase
alloy
a homogeneous mixture of metallic elements with one solid phase
energy
the capacity or ability to do work (nuclear, light or radiant, chemical, heat, electrical, mechanical)
Law of Conservation of Energy
energy cannot be created or destroyed, but only transformed from one form to another. Changes may be accompanied by either the release or absorption of heat energy.
exothermic reaction
releases heat (ex: combustion)
endothermic reaction
absorbs heat (ex: ice melting)
potential energy
available because of position or composition
kinetic energy
energy resulting from motion
Specific Heat Capacity
a physical property of matter, that relates temperature changes to the amount of heat; the amount of heat required to raise the temperature of one gram of a substance one degree Celsius (or Kelvin); (E/m∗∆T)=((J or cal)/ g∗°C)
calorie (cal)
amount of heat required to raise the temperature of one gram of water from 14.5 °C to 15.5 °C
Joule (J)
SI unit of heat energy
Calorie
measure of food energy; determined by burning dried food in such a way that the heat released is used to heat water; its equal to 1000 calories
solution
a homogeneous mixture of two or more substances uniformly dispersed throughout a single phase; frequently liquid
distillation
a process that separates the components of a solution based on their boiling points