matter: properties & changes chapter 3. 3.1 properties of matter matter is very diverse—we...
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Matter: Matter: Properties & Properties & Changes Changes
Chapter 3Chapter 3
3.1 Properties of Matter3.1 Properties of Matter
Matter is very diverse—we must begin to Matter is very diverse—we must begin to organize and describe it.organize and describe it.
What is a substance?What is a substance?
pure; has an unchanging compositionpure; has an unchanging composition
Examples of a substance include…Examples of a substance include…
WaterWater table table saltsalt
& gasoline& gasoline
What is not a substance?What is not a substance?
Sea waterSea water
AirAir
What is a physical property?What is a physical property? A characteristic that can be A characteristic that can be
observed/measured without changing the observed/measured without changing the compositioncomposition
Examples…Examples…
Examples… shape, weight, color, Examples… shape, weight, color, density, odor, taste, hardness, density, odor, taste, hardness, melting/boiling point.melting/boiling point.
(If they have consistent composition= (If they have consistent composition= they have consistent phys property.)they have consistent phys property.)
2 types of phys 2 types of phys propertiesproperties
Extensive property-Extensive property- dependent on the dependent on the
amount of subamount of sub Ex.Ex.
Intensive property-Intensive property- independent of the independent of the
amount of subamount of sub Ex.Ex.
Gold miners… gold vs. fools goldGold miners… gold vs. fools gold
What is a chemical property?What is a chemical property? Ability of a substance to combine with of Ability of a substance to combine with of
change into one or more other substances.change into one or more other substances.
Examples…Examples…
ironiron
1. iron forming rust when combined with 1. iron forming rust when combined with air.air.
2. iron has no reaction with nitrogen gas.2. iron has no reaction with nitrogen gas.
What are some physical properties of copper?What are some physical properties of copper?
What are some chemical properties of copper?What are some chemical properties of copper?
What are some phys/chem What are some phys/chem properties of water?properties of water?
Phys. prop.Phys. prop. Chem. prop.Chem. prop. Reacts with metalsReacts with metals Good solventGood solvent pHpH
States of MatterStates of Matter
States of MatterStates of Matter
Solid- Solid- will not conform to a will not conform to a containercontainer
Definite shape? Definite shape? yesyes
Definite volume? Definite volume? yesyes
Examples… Examples… How are particles How are particles
arranged? arranged? Tightly packedTightly packed
Particle movement?Particle movement? No (very little)No (very little)
States of MatterStates of Matter
Liquids- Liquids- matter that flowsmatter that flows
Definite shape? Definite shape? nono
Definite volume? Definite volume? yesyes
Examples…Examples…How are particles How are particles
arranged? arranged? They are less closely packedThey are less closely packed
Particle movement?Particle movement?yesyes
States of MatterStates of Matter
GasesGases- - matter that flowsmatter that flows Definite shape? Definite shape?
nono Definite volume? Definite volume?
nono Examples…Examples… How are particles arranged? How are particles arranged?
Very far apart Very far apart Particle movement? Particle movement?
yesyes Fills entire container? Fills entire container?
yesyes Compressed? Compressed?
Very compressible Very compressible
Gas versus VaporGas versus Vapor
GASGAS Naturally gaseousNaturally gaseous
Ex. Ex.
Oxygen gasOxygen gas
VAPORVAPOR A gaseous STATE of A gaseous STATE of
a substancea substance Normally solid/liquid Normally solid/liquid
at room temperatureat room temperature Ex. Ex.
steamsteam
3.2 Changes in Matter3.2 Changes in Matter
Physical changes- changes that do not Physical changes- changes that do not alter the composition of a substance. alter the composition of a substance.
Ex… Ex…
Physical changesPhysical changes
Keywords…Keywords… bend bend grindgrind crush crush MeltMelt freezefreeze boilboil vaporizevaporize condensescondenses
Chemical changes- one or more Chemical changes- one or more substances changes into other substances changes into other substances; aka CHEMICAL REACTIONsubstances; aka CHEMICAL REACTION
Examples… HgO Examples… HgO Hg + O Hg + O22
Chemical changeChemical change
Keywords…Keywords… ExplodesExplodes RustsRusts OxidizesOxidizes CorrodesCorrodes TarnishTarnish FermentFerment Burn Burn RotRot
Chemical changeChemical change
Evidence of chem rxn… pg 63Evidence of chem rxn… pg 63 color changecolor change puts off heat puts off heat odor changeodor change Solid is formedSolid is formed Forms gases.Forms gases.
Conservation of massConservation of mass
Conservation of mass-Conservation of mass- Mass is neither created nor destroyed in any Mass is neither created nor destroyed in any
process, it is conserved. (Mass is recycled.)process, it is conserved. (Mass is recycled.)
Antoine LavoisierAntoine Lavoisier
(1743-1794) (1743-1794)
Conservation of MassConservation of Mass
Mass reactants = Mass products
Ex. HgO (s)Ex. HgO (s) Hg (l) + O Hg (l) + O2 2 (g)(g)
216 g 216 g 200 g + ? 200 g + ?
Reactant Products
(before rxn) (after rxn)
Ex. In an experiment, 10.00 g red mercury (II) Ex. In an experiment, 10.00 g red mercury (II) oxide powder is heated in a test tube where it oxide powder is heated in a test tube where it forms liquid mercury & oxygen gas. 9.26 g of forms liquid mercury & oxygen gas. 9.26 g of liquid mercury was recovered. What is the liquid mercury was recovered. What is the mass of oxygen formed?mass of oxygen formed?
** practice problems 6-9** practice problems 6-9
3.3 Mixtures of Matter 3.3 Mixtures of Matter
What are two broad categories of matter?What are two broad categories of matter? Substance & mixturesSubstance & mixtures
What is a mixture? What is a mixture? Combination of multiple subCombination of multiple sub
2 types of mixtures:2 types of mixtures:
1. Heterogeneous mixture- (not blended 1. Heterogeneous mixture- (not blended smoothly)(can be sep. by phys. means)smoothly)(can be sep. by phys. means)
Ex…Ex… Sand & waterSand & water KetchupKetchup Oil & waterOil & water Others?Others?
2 types of mixtures:2 types of mixtures:
2. Homogeneous mixtures- (blended 2. Homogeneous mixtures- (blended smoothly)(can be sep. by phys.means)smoothly)(can be sep. by phys.means)
A.k.a. “Solutions”A.k.a. “Solutions” Ex…Ex…
Ex…Ex…Type of solutionType of solution Example:Example:
gas- gasgas- gas
gas- liquidgas- liquid
liquid- gasliquid- gas
liquid- liquidliquid- liquid
solid- liquidsolid- liquid
solid- solidsolid- solid
List 4 ways to separate mixtures.List 4 ways to separate mixtures.1. Filtration- separates solid from liquid1. Filtration- separates solid from liquid
Ex. Ex. 2. Distillation- sep. solution of 2 liquids b/c of 2. Distillation- sep. solution of 2 liquids b/c of
different boiling pt.different boiling pt.Ex.Ex.
3. Crystallization- sep of dissolved solid from 3. Crystallization- sep of dissolved solid from solutionsolutionEx.Ex.
4.4. Chromatography- sep. components of a Chromatography- sep. components of a mixture by travellingmixture by travellingEx.Ex.
3.43.4 Elements & Elements & CompoundsCompounds
What is an element?What is an element? A pure sub that cannot be further broken downA pure sub that cannot be further broken down Ex… Na, N, Ca, O etcEx… Na, N, Ca, O etc
What is a chemical symbol?What is a chemical symbol?
How many naturally occuring element are How many naturally occuring element are there? there? 9191 H>FrH>Fr
3.43.4 Elements & Elements & CompoundsCompounds
What was Dmitri Mendeleev’s most significant What was Dmitri Mendeleev’s most significant contribution to chemistry?contribution to chemistry? Chart that organized elements into rows & columns Chart that organized elements into rows & columns
based on similarities.based on similarities.
Horizontal rows are called “periods” Horizontal rows are called “periods” Vertical rows are called “groups” or “family”Vertical rows are called “groups” or “family” Elements of the same group have similar Elements of the same group have similar
physical & chemical properties.physical & chemical properties.
3.43.4 Elements & Elements & CompoundsCompounds
What was so amazing about What was so amazing about Mendeleev’s table?Mendeleev’s table? He left blanks b/c he predicted that there He left blanks b/c he predicted that there
were more elements that haven’t been were more elements that haven’t been discovered yet.discovered yet.
3.43.4 Elements & Elements & CompoundsCompounds
What is a compound?What is a compound? A substance consisting of 2 or more A substance consisting of 2 or more
elements.elements.
Ex… HEx… H22O, NaCl, COO, NaCl, CO22
Compounds can be broken down by Compounds can be broken down by chemical means.chemical means.
3.43.4 Elements & Elements & CompoundsCompounds
Can water be decomposed?Can water be decomposed? Yes, electrolysisYes, electrolysis
Are the properties of a compound the Are the properties of a compound the same as the elements of which it is same as the elements of which it is composed?composed?
NONO Ex.Ex. Sodium- metal solid, soft, highly reactive Sodium- metal solid, soft, highly reactive
with waterwith water Chlorine- gas, yellowish, poisonousChlorine- gas, yellowish, poisonous Salt- crystal solid, hard, white, harmless Salt- crystal solid, hard, white, harmless
Ex.Ex. Oxygen- flammable, for respirationOxygen- flammable, for respiration Hydrogen- flammableHydrogen- flammable Water- not flammableWater- not flammable
What is the Law of Definite Proportion?What is the Law of Definite Proportion? Regardless of mass, a comp. will always Regardless of mass, a comp. will always
have the same proportion.have the same proportion.
Formula for calculating percent by mass:Formula for calculating percent by mass:
mass of elementmass of element X 100% = % by mass X 100% = % by mass
mass of compoundmass of compound
% by mass example% by mass example
Ex. 1Ex. 1 The mass of carbon in a 20.0g sample of The mass of carbon in a 20.0g sample of
sucrose (sugar) is 8.4g. What % by mass is sucrose (sugar) is 8.4g. What % by mass is carbon?carbon?
% by mass example% by mass example
Ex. 2 Ex. 2 You have a 500. g sample of sucrose. You have a 500. g sample of sucrose.
Carbon in this sample has a mass of 210.5g. Carbon in this sample has a mass of 210.5g. What percent by mass is carbon?What percent by mass is carbon?
** Practice problems p. 76 #20-23** Practice problems p. 76 #20-23
What is the law of Multiple proportions?What is the law of Multiple proportions? Chemicals with different ratios of elements Chemicals with different ratios of elements
are different compounds.are different compounds. Can compounds composed of the same Can compounds composed of the same
element be different compounds?element be different compounds? Yes. If they have different mass ratiosYes. If they have different mass ratios Ex. HEx. H220- water0- water
HH22OO22 – hydrogen peroxide – hydrogen peroxide
STOPSTOP
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