Matter chapter 3
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Transcript of Matter chapter 3
MatterMatter
chapter 3chapter 3
MatterMatter
Anything that has massmass and occupies spacespace
–MassMass is measured in gramsgrams or kilogramskilograms
–Space or volumevolume is measured in litersliters or cmcm33
PhasesPhases• SOLIDS• LIQUIDS• GASES
Solid:Solid: •definite volume •definite shape
LiquidLiquid
•definite volume •indefinite shape
•takes the shape of container
GasGas
•indefinite volume •indefinite shape
•takes the shape and volume of container
States of Matter
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1. How are the particles packed in each phase?
2. How do the particles move in each phase?
3. Why do liquids and gases flow?4. Why are gases so easy to compress?
4th Phase of matter
•PlasmaPlasma •exists in stars •electrons are stripped from atoms
Physical PropertiesPhysical Properties•Describe the appearance
and form of matter
Words:Words: • color, texture, luster, odor, solid, liquid, gasMeasurements:Measurements:
• a number and a unit
Intensive propertiesIntensive properties–Physical ConstantsPhysical Constants – independentindependent of sample size
•Density, freezing point, and melting point
•Solubility in water (g/ml)
Extensive PropertiesExtensive Properties
•Mass volume •depends on amountamount of matter in sample
•Extensive propertiesExtensive properties depend on quantity of matter
Chemical PropertiesChemical Properties•Describe how matter behaves
in presence of other matter•Describe how matter changes
into another kind of matter– Flammability– Resistance to corrosion– Ability to neutralize acids or
bases
Properties of CopperProperties of CopperPhysical Prop.
• Reddish brown• Shiny• Malleable• Ductile• Good Conductor• Density = 8.92
g/cm3
• MP = 1085C• BP = 2570C
Chemical Prop.• Reacts to form
green copper carbonate
• Forms a deep blue solution when in contact with NH3
• Forms new substances with HNO3
Physical ChangePhysical Change•The form or appearance of sample
may change but identityidentity remains same– Cutting, crushing, grinding,tearing– Phase changes– Dissolving
Dissolving
•Dissolving is physical change•Think of sugar in water
•still have sugar – you just spread it out with water molecules in between
•C6H12O6(s) C6H12O6(aq)
Phase Changes•Phase changes are physical
changes•No new substance is created
(chemical formula stays the same)•Ex:
• ice melting: H2O(s) H2O(l)
•water boiling: H2O (l) H2O(g)
Chemical ChangeChemical Change•chemical change - identity of
matter is changed•new substance with unique
properties is formed•The chemical formula changes•Ex: 2H2O(l) 2H2(g) + O2(g)
Burning• Common name for oxidation reactionoxidation reaction• Burning means reacting with oxygen• Burning is chemical change, because
original substance is changed into new kinds of matter
Ex: CH4(g) + 2O2(g) CO2(g) + 2H2O(g)
What kinds of matter are there?
Matter
Substances Mixtures
Elements CompoundsHeterogeneousMixtures
HomogeneousMixtures
Mixtures Separated by physical methodsCompounds Separated by chemical methods
ElementElement
•Substance that:•cannot be broken down or
decomposed into simpler substance•only 1 kind of atom•has definite properties
•Formulas have 1 uppercase letter
Element Song
AtomAtom
•smallest particle of element that retains properties of element
•smallest particles of element that can undergo a chemical reaction
CompoundsCompounds• 2 or more elements chemically
combined in a definite ratio• Properties are differentdifferent from those of
elements formed from• Homogeneous• Broken into elements by chemical
decomposition reaction• Formulas have 2 or more uppercase
letters
2Na + Cl2 2NaCl
MixturesMixtures
•Combo of 2 or more pure substances
•Physically combined notnot chemically combined
•Each substance retains its own identity and properties
MixturesMixtures•Variable composition•No unique properties
(Think of sugar and salt mixed together)
•Separated by physical methodsphysical methods•May be homogeneous or
heterogeneous
TypesTypes of Mixtures of Mixtures• Heterogeneous: See a boundary
or regions that look different–Ex: Colloids Suspensions ice water granite
Colloids• particles larger than size of molecule but smaller
than particles seen with naked eye
• colloidal dispersion– consists of colloids in a dispersing medium
• Ex: whipped cream, mayonnaise, milk, butter, gelatin, jelly, colored glass
Aerosols: –solid or liquid particles in gasEx: •Smoke: solid in a gas•Fog: liquid in a gas
Sols: –solid particles in a liquidEx: •Milk of Magnesia (solid magnesium hydroxide in water)
Emulsions: –liquid particles in liquidEx: •Mayonnaise: oil in water
Gels: –liquids in solidEx: •Gelatin: protein in water •Quicksand: sand in water
Suspensions• particles in suspensions are larger
than those in solutions• components of suspension can be
evenly distributed by mechanical means (shaking the contents) but components will settle out
• Homogeneous: constant composition throughout, single phase– Ex: Solutions (all 3 phases) such as air, windex, kool-aid
Hints for MixturesHints for Mixtures• Solutions in gas & liquid phases transmit light
• particles not big enough to scatter light • look translucent
• Suspensions look cloudy • particles big enough to scatter light• settle on standing
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CuSO4(aq)
Particle Diagrams
Atoms of a monatomic element
Molecules of a diatomic element
Particle Diagrams
Molecules of a triatomic compound
Mixture: monatomic element, diatomic element, triatomic compound
Separating MixturesSeparating Mixtures• Physically combined• Separation based on physical properties
– Sorting: size & appearance– Filtration: size solid in liquid– Distillation: different bp’s liquids mixed– Crystallization: solubility solid in liquid– Magnet: magnetization – Chromatography: solubility liquids mixed
– “Travel” ability
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Paper Chromatograhy
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Conservation of MassConservation of Mass
Mass before = Mass after
# of atoms before = # of atoms after