Unit 1 Unit 1 Matter: Properties and Matter: Properties and

ChangeChange

Matter: Properties and Matter: Properties and ChangeChangeObjectivesObjectives Students should be able to:Students should be able to:• Distinguish between chemical and physical propertiesDistinguish between chemical and physical properties

• Apply the Law of Conservation of Mass to chemical Apply the Law of Conservation of Mass to chemical reactionsreactions

• Classify matter as elements, compounds, or mixturesClassify matter as elements, compounds, or mixtures

• Contrast homogenous and heterogeneous mixturesContrast homogenous and heterogeneous mixtures

• Describe techniques used to separate mixturesDescribe techniques used to separate mixtures

What is matter?What is matter?

• MatterMatter – anything that takes up – anything that takes up space and has mass.space and has mass.

• MassMass – a measure of the amount of – a measure of the amount of matter in an objectmatter in an object

• Weight is due to gravity; it changes Weight is due to gravity; it changes from location to location; mass is from location to location; mass is always constant.always constant.

States of MatterStates of MatterDefinitDefinite e ShapeShape

DefinitDefinite e VolumVolumee

TemperaturTemperature increasee increase

CompressibCompressiblele

SolidSolid Yes Yes Yes Yes Small Small expansion expansion

No No

LiquiLiquidd

No No Yes Yes Small/Small/moderate moderate expansionexpansion

No No

Gas/Gas/

VapoVaporr

No No No No Large Large expansion expansion

Yes Yes

•VaporVapor – gas form of a substance – gas form of a substance that is normally a liquid at room that is normally a liquid at room temperature.temperature.

Types of MatterTypes of Matter

I. I. PurePure SubstanceSubstance- one particular kind of - one particular kind of matter; is uniform (all the same) and has matter; is uniform (all the same) and has a definite composition a definite composition

A. A. ElementsElements – simplest kind of matter – simplest kind of matter

• cannot be broken down any simplercannot be broken down any simpler

• composed of only composed of only oneone kind of atom. kind of atom.

• written shorthand w/ chemical symbols written shorthand w/ chemical symbols

ex: carbon = C, iron = Fe, mercury = Hgex: carbon = C, iron = Fe, mercury = Hg

B. B. CompoundsCompounds – made of – made of two or moretwo or more elements, elements, chemically combined chemically combined

• broken down broken down onlyonly by chemical change by chemical change

• when broken down, pieces have different when broken down, pieces have different properties than original compound.properties than original compound.

• adhere to adhere to Law of Definite ProportionsLaw of Definite Proportions – – compound is always made of the same compound is always made of the same elements in the same proportions by masselements in the same proportions by mass

ex: water = Hex: water = H22O, 2:1 ratio H to OO, 2:1 ratio H to O

methane = CHmethane = CH44, 4:1 ratio H to C, 4:1 ratio H to C

II. II. MixtureMixture- more than one kind of - more than one kind of matter physically combined matter physically combined

– has a variable compositionhas a variable composition– each part keeps its own propertieseach part keeps its own properties– can be separated by physical means can be separated by physical means

A. A. HeterogeneousHeterogeneous- mixture is not - mixture is not uniform in composition, (visibly uniform in composition, (visibly different parts)different parts)

ex: chocolate chip cookie, soilex: chocolate chip cookie, soil

B. B. HomogeneousHomogeneous- same composition - same composition throughout; (all looks the same); throughout; (all looks the same);

Aka - Aka - solutionssolutions

ex: Gatorade, air, salt waterex: Gatorade, air, salt water

Separating MixturesSeparating Mixtures• DistillationDistillation – separates components of – separates components of

solution w/ different boiling points solution w/ different boiling points

• FiltrationFiltration – separates solid from a liquid – separates solid from a liquid using porous barrierusing porous barrier

• Crystallization Crystallization – forms pure solid – forms pure solid particles from a saturated solution of particles from a saturated solution of dissolved particlesdissolved particles

• ChromatographyChromatography – separates – separates components (mobile phase) across a components (mobile phase) across a piece of paper (stationary phase)piece of paper (stationary phase)

Properties of MatterProperties of MatterI.I. Physical Properties Physical Properties – can be – can be

observed and measured without observed and measured without changing the composition.changing the composition.

• color, odor, texture, hardness, density, color, odor, texture, hardness, density, melting and boiling pts.melting and boiling pts.

Physical changePhysical change – change in – change in appearance without changing the appearance without changing the composition.composition.

ex: boil, freeze, dissolve, melt, ex: boil, freeze, dissolve, melt, condense, cut, bend, split, crackcondense, cut, bend, split, crack

II. Chemical Properties II. Chemical Properties – can only – can only be observed by changing the be observed by changing the composition of the material. composition of the material.

• Chemical changeChemical change – a change where a – a change where a new kind of matter is formed.new kind of matter is formed.

ex: rust, rot, explode, burn, ex: rust, rot, explode, burn, decompose, fermentdecompose, ferment

Indications of a Chemical Indications of a Chemical ChangeChange

• EnergyEnergy absorbed or released – absorbed or released – temperature gets hotter/coldertemperature gets hotter/colder

• ColorColor change (sometimes) change (sometimes)

• GasGas production – bubbling, fizzing, or production – bubbling, fizzing, or odor changeodor change

• PrecipitatePrecipitate formed – solid that formed – solid that separates from solution and won’t re-separates from solution and won’t re-dissolvedissolve

Law of Conservation of Law of Conservation of MassMass• matter can not be created or destroyed matter can not be created or destroyed

in chemical reactions – it is conservedin chemical reactions – it is conserved

Example: 2Na + ClExample: 2Na + Cl22 2 NaCl 2 NaCl

reactantsreactants products products

200 g + 15 g = 215 g200 g + 15 g = 215 g

mass of reactants = mass of mass of reactants = mass of productsproducts

A. Extensive vs. IntensiveA. Extensive vs. Intensive

• Extensive PropertyExtensive Property

– depends on the amount of matter depends on the amount of matter presentpresent

• Intensive PropertyIntensive Property

– depends on the identity of substance, depends on the identity of substance, not the amountnot the amount

A. Extensive vs. IntensiveA. Extensive vs. Intensive

• Examples:Examples:

– boiling pointboiling point

– volumevolume

– massmass

– densitydensity

– conductivityconductivity

intensiveintensive

extensiveextensive

extensiveextensive

intensiveintensive

intensiveintensive

B. Physical vs. ChemicalB. Physical vs. Chemical

• Physical PropertyPhysical Property

– can be observed without changing the can be observed without changing the identity of the substanceidentity of the substance

• Chemical PropertyChemical Property

– describes the ability of a substance to describes the ability of a substance to undergo changes in identityundergo changes in identity

B. Physical vs. ChemicalB. Physical vs. Chemical

• Examples:Examples:

– melting pointmelting point

– flammableflammable

– densitydensity

– magneticmagnetic

– tarnishes in airtarnishes in air

physicalphysical

chemicalchemical

physicalphysical

physicalphysical

chemicalchemical

B. Physical vs. ChemicalB. Physical vs. Chemical

• Physical ChangePhysical Change

– changes the form of a substance without changes the form of a substance without changing its identitychanging its identity

– properties remain the sameproperties remain the same

• Chemical ChangeChemical Change

– changes the identity of a substancechanges the identity of a substance

– products have different propertiesproducts have different properties

B. Physical vs. ChemicalB. Physical vs. Chemical

• Signs of a Chemical ChangeSigns of a Chemical Change

– change in color or odorchange in color or odor

– formation of a gasformation of a gas

– formation of a precipitate (solid)formation of a precipitate (solid)

– change in light or heatchange in light or heat

B. Physical vs. ChemicalB. Physical vs. Chemical

• Examples:Examples:

– rusting ironrusting iron

– dissolving in waterdissolving in water

– burning a logburning a log

– melting icemelting ice

– grinding spicesgrinding spices

chemicalchemical

physicalphysical

chemicalchemical

physicalphysical

physicalphysical