2-1 Chemical & Physical Properties

Warm-UpWarm-UpWhat is matter?What is matter?– Matter is anything that has mass and takes up Matter is anything that has mass and takes up

space.space.

Which of the following sets of measurements Which of the following sets of measurements are more precise?are more precise?– 2.74 cm2.74 cm 2.743 cm2.743 cm– 102.3 g102.3 g 102 g102 g– 0.012 L0.012 L 0.0002 L0.0002 L

2-1: Chemical & Physical Properties2-1: Chemical & Physical PropertiesDistinguishDistinguish between physical & chemical between physical & chemical properties.properties.

IdentifyIdentify the characteristics of a substance. the characteristics of a substance.

DifferenctiateDifferenctiate among physical states of among physical states of matter.matter.

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

Law of Conservation of Law of Conservation of Mass/MatterMass/Matter

- Matter cannot be - Matter cannot be createdcreated or or destroyeddestroyed in an ordinary chemical in an ordinary chemical

reaction just reaction just rearrangedrearranged to form to form different different substancessubstances

Matter can be Matter can be describeddescribed using using propertiesproperties..

EXTENSIVE

PHYSICAL CHEMICAL

INTENSIVE

PROPERTIES

Characteristics of MatterCharacteristics of MatterPhysical PropertiesPhysical Properties– CharacteristicsCharacteristics of a substance that can be of a substance that can be

observedobserved without the production of a without the production of a newnew substance.substance.

Examples:Examples:– colorcolor– smellsmell– tastetaste– hardnesshardness– densitydensity– texturetexture– solubilitysolubility

– melting pointmelting point– boiling pointboiling point– freezing pointfreezing point– magnetic attractionmagnetic attraction– electrical electrical

conductivityconductivity– temperaturetemperature– state or phasestate or phase

Two types of Physical Two types of Physical PropertiesProperties

1.1. ExtensiveExtensiveDepends on the Depends on the particular sampleparticular sample

for example: volume, mass, weight, for example: volume, mass, weight, shape, etc…shape, etc…

2.2. IntensiveIntensiveDepends on the type of Depends on the type of mattermatter NOT NOT how muchhow much there is there is

For example: color, melting point, specific For example: color, melting point, specific heat, density, appearance, etc…heat, density, appearance, etc…

Chemical PropertiesChemical Properties– describes how a substance describes how a substance reactsreacts or or

fails to fails to reactreact with other with other substancessubstances to to produce produce newnew substances. substances.

Examples:Examples:– OxidationOxidation– CorrosionCorrosion– HydrolysisHydrolysis

– CombustionCombustion– FlammabilityFlammability– Reaction to Acid or Base.Reaction to Acid or Base.

Two Types of ChangesTwo Types of Changes1.1. PhysicalPhysical Change Change

an an alterationalteration of a substance that of a substance that onlyonly changes the physical changes the physical propertiesproperties of the of the substance.substance.

**DoesDoes notnot changechange the the chemical chemical composition composition of the matter!!of the matter!!

2.2. ChemicalChemical Change Change

a a changechange of the chemical of the chemical compositioncomposition of a of a substance that results in the formation of a substance that results in the formation of a new substancenew substance

– ALWAYS forms a ALWAYS forms a new substancenew substance that that has has differentdifferent physical and chemical properties than physical and chemical properties than the original substance. the original substance.

*Also known as a chemical reaction. *Also known as a chemical reaction.

Recognizing Chemical ChangeRecognizing Chemical ChangeChange in ColorChange in Color– Copper turns green.Copper turns green.

Production of GasProduction of Gas– Baking soda in vinegar Baking soda in vinegar

produce COproduce CO22..

Formation of PrecipitateFormation of Precipitate– Any formation of a solid that Any formation of a solid that

separates from liquid. separates from liquid.

Energy releaseEnergy release– Heat or light given off.Heat or light given off.

KineticKinetic Theory of MatterTheory of MatterAll matter is made of All matter is made of tinytiny particlesparticles in in constant motion.constant motion.

Potential Energy (PE)Potential Energy (PE)– energy due to the position or conditionenergy due to the position or condition– at the atomic level: at the atomic level: the distance between the distance between

the particlesthe particles

closer= closer= lower PElower PE farther = farther = higher PEhigher PE

Kinetic Energy (KE)Kinetic Energy (KE)energy due to motionenergy due to motion

Faster=Faster=higher KEhigher KE Slower= Slower= lower KElower KE

State State or or PhasePhase

Particle Particle level level picturepicture

Particles Particles descriptiondescription

Keep Keep VolumeVolume

??

Keep Keep shapeshape

??

SolidSolid

LiquidLiquid

GasGas

Arranged in orderly pattern

Yes Yes

Touching, but not tightly packed

Yes No

Far apart and rarely touching

No No

State State or or PhasePhase

Particle Particle MovementMovement

Amount PEAmount PE Amount KEAmount KE ExampleExample

SolidSolid

LiquidLiquid

GasGas

Very Low

Ice

Low Water

High Vapor

Vibrational only

Vibrational & translational

Move freely

Low

Medium

High

PlasmaPlasma– extraordinaryextraordinary state of matter state of matter – consists of consists of highhigh energy particles energy particles– electrons are stripped from their nucleielectrons are stripped from their nuclei

examplesexamples: : – fluorescent lightsfluorescent lights– stars stars – lightninglightning

*Most Abundant State of Matter in *Most Abundant State of Matter in the the Universe!*Universe!*

Phase Changes – Changes of StatePhase Changes – Changes of StateAdding or removing energy (heat) to a Adding or removing energy (heat) to a substance causes phase changessubstance causes phase changes

The particles potential energy is increased The particles potential energy is increased or decreased.or decreased.

During a phase change, temperature does During a phase change, temperature does NOTNOT change change

Phase changesPhase changesMelting S ΔMelting S Δ L L (adding energy)(adding energy)

Freezing L Freezing L ΔΔ S S (removing energy)(removing energy)

*Melting point & freezing point of a substance *Melting point & freezing point of a substance occur at the same temperature.occur at the same temperature.

Phase changesPhase changesBoilingBoiling L L ΔΔ G G (adding energy)(adding energy)

Condensation Condensation G G ΔΔ L L (removing (removing energy)energy)

Evaporation L Evaporation L ΔΔ G G (adding energy)(adding energy)

*Difference between boiling & evaporation:*Difference between boiling & evaporation:– Boiling Boiling a specific temp. below the surface a specific temp. below the surface– Evaporation Evaporation any temp. at the surfaceany temp. at the surface

Phase changesPhase changesDeposition G Deposition G ΔΔ S (removing energy) S (removing energy)

-Examples: -Examples:

snowsnow

frostfrost

Sublimation S Sublimation S ΔΔ G (adding energy) G (adding energy)

-Examples: -Examples:

solid COsolid CO22 (dry ice) (dry ice)

solid air freshenerssolid air fresheners