Matter: Properties & Change
description
Transcript of Matter: Properties & Change
Matter: Properties & ChangeMatter: Properties & ChangeChapter 3
MatterMatter
Matter – anything that has mass and takes up space
Everything around us
Chemistry – the study of matter and the changes it undergoes
Four States of MatterFour States of Matter
Solidsparticles vibrate but can’t move
aroundfixed shape fixed volumeincompressible
Four States of MatterFour States of Matter
Liquidsparticles can move
around but are still close together
variable shapefixed volumeVirtually incompressible
Four States of MatterFour States of Matter
Gasesparticles can separate and
move throughout containervariable shapevariable volumeEasily compressedVapor = gaseous state of a
substance that is a liquid or solid at room temperature
Four States of MatterFour States of Matter
Plasmaparticles collide with enough energy
to break into charged particles (+/-)gas-like, variable
shape & volumestars, fluorescent
light bulbs, TV tubes
Physical PropertiesPhysical Properties
Physical Propertycan be observed without changing the
identity of the substance
Physical PropertiesPhysical Properties
Physical properties can be described as one of 2 types:
Extensive Propertydepends on the amount of matter
present (example: length)
Intensive Propertydepends on the identity of substance, not
the amount (example: scent)
Extensive vs. IntensiveExtensive vs. Intensive
Examples:boiling point
volume
mass
density
conductivity
Density – a physical propertyDensity – a physical property
Derived units = Combination of base units
Volume (m3 or cm3 or mL) length length length Or measured using a
graduated cylinder
D = MV
1 cm3 = 1 mL1 dm3 = 1 L
Density (kg/m3 or g/cm3 or g/mL)mass per volume
DensityDensity An object has a volume of 825 cm3 and a
density of 13.6 g/cm3. Find its mass.
GIVEN:
V =
D =
M = ?
WORK:
V
MD
DensityDensity A liquid has a density of 0.87 g/mL. What
volume is occupied by 25 g of the liquid?
GIVEN:
D =
V =
M =
WORK:
V
MD
DensityDensityM
ass
(g)
Volume (cm3)
Δx
Δyslope D
V
M
= g/cm3units of yunits of x
Units of the slope
ProportionsProportions
Direct Proportion
Inverse Proportion
xy
xy
1
y
x
y
x
Percent ErrorPercent Error
Indicates accuracy of a measurement
100literature
literaturealexperimenterror %
your value
accepted value
Percent ErrorPercent Error
A student determines the density of a substance to be 1.40 g/mL. Find the % error if the accepted value of the density is 1.36 g/mL.
100g/mL 1.36
g/mL 1.36g/mL 1.40error %
% error = 0.04/1.36 = 3 %
Chemical PropertiesChemical Properties
Chemical Propertydescribes the ability of a substance to
undergo changes in identity
Physical vs. Chemical PropertiesPhysical vs. Chemical Properties
Examples:melting point
flammable
density
magnetic
tarnishes in air
Physical ChangesPhysical Changes
Physical Changechanges the form of a substance without
changing its identity
properties remain the same
Examples: change in shape or size, dissolving, change in color by dying, all phase changes,
Phase Changes – PhysicalPhase Changes – Physical
Evaporation =
Condensation =
Melting =
Freezing =
Sublimation =
Chemical ChangesChemical Changes
Process that involves one or more substances changing into a new substanceCommonly referred to as a chemical
reactionNew substances have different
compositions and properties from original substances
Chemical ChangesChemical Changes
Signs of a Chemical Changechange in color or odor (not by dying)
formation of a gas (bubbling)
formation of a precipitate (solid)
change in light or heat
Physical vs. Chemical ChangesPhysical vs. Chemical Changes
Examples:rusting iron
dissolving in water
burning a log
melting ice
grinding spices
What Type of Change?What Type of Change?
Matter FlowchartMatter Flowchart
MATTER
Can it be physically separated?
yes no
Can it be chemically decomposed?
noyesIs the composition uniform?
noyes
Pure SubstancesPure Substances
Elementcomposed of identical atomsEX: copper wire, aluminum foil
Pure SubstancesPure Substances
Compoundcomposed of 2 or more
elements in a fixed ratio
properties differ from those of individual elements
EX: table salt (NaCl)
MixturesMixtures
Variable combination of 2 or more pure substances.
Heterogeneous Homogeneous
MixturesMixtures
Solutionhomogeneousvery small particlesparticles don’t settleEX: rubbing alcohol
MixturesMixtures
Heterogeneousmedium-sized to
large-sized particles
particles may or may not settle
EX: milk, fresh-squeezed
lemonade
MixturesMixtures
Examples:tea
muddy water
fog
saltwater
Italian salad dressing