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Matter and Change Matter and Change
What is chemistry? What is chemistry? The study of what The study of what thingsthings are made of are made of
and the changes they undergo.and the changes they undergo.
Please do now!Please do now!
Work independently.Work independently.
Write two professions (not teaching) that Write two professions (not teaching) that use chemistry knowledge every day.use chemistry knowledge every day.
Think about your daily routine. List two Think about your daily routine. List two things that you do each day that involves things that you do each day that involves chemistry.chemistry.
Name one thing in your life that has Name one thing in your life that has nothing to do with chemistry.nothing to do with chemistry.
There are five major divisions of There are five major divisions of chemistry:chemistry:
organicorganic=containing carbon =containing carbon CC (mostly living (mostly living things) things)
inorganicinorganic=NOT containing carbon (nonliving =NOT containing carbon (nonliving things)things)
analyticalanalytical=composition of substances (what =composition of substances (what they are made of)they are made of)
physicalphysical=how things behave; reasons why=how things behave; reasons why
biochemistrybiochemistry=living organisms (animal body =living organisms (animal body functions)functions)
So what are their jobs?So what are their jobs?
Pharmacists researching Pharmacists researching new cancer drugsnew cancer drugsCrime scene investigators Crime scene investigators (CSI) = forensics(CSI) = forensicsAnthropologists – how Anthropologists – how were the mummies were the mummies preserved?preserved?Doctors investigate the Doctors investigate the processes that lead to processes that lead to liver diseaseliver diseaseChefs creating new Chefs creating new recipesrecipes
Pure vs. AppliedPure vs. Applied
PUREPURE
UncontaminatedUncontaminated
Knowledge for knowledge sake Knowledge for knowledge sake
Objective – just the factsObjective – just the facts
Pure vs. AppliedPure vs. Applied
APPLIEDAPPLIED
Takes the scientific knowledge of Takes the scientific knowledge of pure chemistry and uses it to pure chemistry and uses it to effect people or the environment.effect people or the environment.
ThingsThings=matter=anything that =matter=anything that has has massmass or takes up space or takes up space
Classifying MatterClassifying Matter
States of matter: solid, liquid, gasStates of matter: solid, liquid, gas
ChangesChanges
These are also called These are also called “phases”“phases”
Phases of matter are solid, Phases of matter are solid, liquid, gas.liquid, gas.
States of matterStates of matter
Organized according to how Organized according to how particles in that matter behave particles in that matter behave (or move around).(or move around).
How does it move?How does it move? Does it have shape?Does it have shape? Does it have definite volume?Does it have definite volume?
SOLIDSOLID
Does not flow.Does not flow. Definite shape.Definite shape. Definite volume.Definite volume.
LIQUIDLIQUID
It flows.It flows. Takes on the shape of its container.Takes on the shape of its container. Has a definite volume.Has a definite volume.
GASGAS
It flows.It flows. Takes on the shape of its containerTakes on the shape of its container Has NO definite volume-takes on Has NO definite volume-takes on
the volume of its container.the volume of its container.
Why do they behave this way?Why do they behave this way?
Amount of Amount of
space between the particles.space between the particles.
Physical properties
alters a substance w/o changing its composition
Types of physical properties
Extensive property: depends on the AMOUNT of matter in a substance
Mass, volume
Intensive property: depends on the TYPE of matter in a substanceHardness, luster, odor
Examples of physical properties
color density tastesolubility or dissolve – abilityANY PHASE CHANGE
Phase changesPhase changes
Are changes in state of matterAre changes in state of matterTypes of phase changes: Types of phase changes:
boil boil melt melt
freeze, solidify, crystallizefreeze, solidify, crystallizeevaporateevaporate
distilldistillsublimesublime
More phase changes:More phase changes:
distillationdistillation-a liquid is boiled to -a liquid is boiled to produce a vapor which is then produce a vapor which is then condensed again to a liquidcondensed again to a liquid
sublimationsublimation-skips a phase-goes from -skips a phase-goes from solid to gas or vapor without solid to gas or vapor without becoming a liquidbecoming a liquid
(moth balls, dry ice, air fresheners)(moth balls, dry ice, air fresheners)
Chemical properties
how a substance how a substance reactsreacts with with something elsesomething else
Chemical equation: Chemical equation: REACTANTS REACTANTS PRODUCTS PRODUCTS
means “yields”means “yields”
Examples ofChemical properties
flammability flammability
combustioncombustion
neutralization neutralization
REACTS WITHREACTS WITH
Physical change
the original substance still exists, it the original substance still exists, it has only changed in form (size, has only changed in form (size, shape, phase)shape, phase)
the original the original chemical formulachemical formula is still is still in tact!in tact!
Physical changes: in the labPhysical changes: in the labWords that indicate that aWords that indicate that a PHYSICAL CHANGEPHYSICAL CHANGE
has taken place:has taken place:
dissolvedissolve melt melttear tear freeze freezegrind grind evaporate evaporatecutcut (ALL phase (ALL phase
changes)changes)
Examples of a physical change:Examples of a physical change:
– Iron is more dense than aluminumIron is more dense than aluminum
– Mercury melts at -39Mercury melts at -39ooCC
– Oil and water do not mixOil and water do not mix
– Sugar dissolves in waterSugar dissolves in water
– Water boils and becomes steamWater boils and becomes steam
– A tire is inflated with airA tire is inflated with air
Chemical change
a new substance is produced
results in the rearrangement of atoms so that new substance has a new set ofproperties eg: H2O
The original chemical formula comes apart!
Examples of a chemical change
– Iron and oxygen form rust
– Magnesium burns brightly when ignited
– Milk sours
– HCl reacts with KOH to produce salt, water and heat
Chemical changes: in the labChemical changes: in the lab
– precipitateprecipitate forms forms– gas released (bubbles) gas released (bubbles) – color changecolor change– odor odor – energy transfer occurs energy transfer occurs
((exothermicexothermic or or endothermicendothermic))
Concept of irreversibilityConcept of irreversibility
Chemical changes: in the labChemical changes: in the labWords that indicate that aWords that indicate that a
CHEMICAL CHANGECHEMICAL CHANGEhas taken place: has taken place:
rotrot rustrustdecomposedecompose fermentferment
growgrow decaydecaycorrodecorrode sprout sprout
Energy and chemical changesEnergy and chemical changes
some chemical reactions absorb or give off energy in the form of heat or light
Energy and chemical changesEnergy and chemical changes
SYSTEM: focus of our attention
SURROUNDINGS: everything outside of the system
Energy and chemical changesEnergy and chemical changes
Exothermic – energy is given off by the system to the surroundings
SYSTEM SURROUNDINGS (you feel heat)
Endothermic – energy is taken into the system from the surroundings
SYSTEM SURROUNDINGS (you feel cold)energy
energy
Real life exampleReal life example
When baking soda (NaHCO3) is mixed with some types of cookie dough, the dough is baked in a hot oven; the baking soda absorbs energy and breaksapart into CO2, H2O, and Na2CO3. The CO2 (a gas) and H2O (in the form of steam, a
gas) puff up the cookies.
Law of Conservation of EnergyLaw of Conservation of Energy•During any chemical or physical change, the total amount of energy remains THE SAME
•Energy can not be created or destroyed
•Energy is transferred but never lost
HeatHeat
•energy that is transferred between objects that are at different temperatures
•heat always moves from warm to cold
•heat is a form of kinetic energy
How do we measure heat?How do we measure heat?
Use a thermometer to measure Use a thermometer to measure temperaturetemperature which tells us about the which tells us about the average kinetic energyaverage kinetic energy of the molecules in of the molecules in the substancethe substance
Speaking of conservation…Speaking of conservation…
Remember the Remember the law of conservation of____law of conservation of____
Mass, matter, energyMass, matter, energy
Each is conserved Each is conserved or equalor equal on both sides on both sides of the arrow in a chemical equationof the arrow in a chemical equation
Total g on LEFT is equal to total g on RIGHTTotal g on LEFT is equal to total g on RIGHT
Classification of MatterClassification of Matter
Matter can be...Matter can be...
ELEMENTELEMENT: located on : located on PT; cannot be PT; cannot be separated into simpler separated into simpler substances (Fe)substances (Fe)
COMPOUNDCOMPOUND: 2 or more : 2 or more different elements different elements chemically combined; chemically combined; present in same ratio present in same ratio (H(H220 and H0 and H22OO22))
SUBSTANCESUBSTANCE
– you can write a you can write a chemical formula chemical formula for them (from for them (from the PT)the PT)
– cannot be easily cannot be easily separated (NaCl separated (NaCl or Hor H22O)O)
Matter can be...Matter can be...
HOMOGENEOUSHOMOGENEOUS: : same throughout same throughout (Hershey Bar)(Hershey Bar)
HETEROGENEOUSHETEROGENEOUS: : different throughout different throughout (Snickers Bar)(Snickers Bar)
MIXTUREMIXTURE– physical blend of 2 or physical blend of 2 or
more substancesmore substances– easily separated easily separated
(salad)(salad)
– Classified by Classified by how how well mixedwell mixed they are! they are!
RememberRemember
All All solutionssolutions are mixtures are mixtures
Common solutions:Common solutions:
Air
carbon dioxide and oxygen in nitrogen
gas-gas
Soda water
carbon dioxide in water
gas-liquid
Vinegar
acetic acid in water
liquid-liquid
Please do now!Please do now!
Work independently.Work independently.
Handout “Matter-Substance vs. Mixture” Handout “Matter-Substance vs. Mixture” p. 17p. 17
Is the type of matter listed a Is the type of matter listed a substancesubstance or or a a mixturemixture? ?
substancesubstance ==> element or compound ==> element or compound
mixturemixture ==> hetero or homogeneous ==> hetero or homogeneous
Mixtures are easy to separateMixtures are easy to separate
Methods of separation:Methods of separation:
–DecantDecant (pour off) – oil and water (pour off) – oil and water
–FiltrationFiltration – separates a solid from a – separates a solid from a liquid - muddy waterliquid - muddy water
–DistillationDistillation – salt water – salt water
–ChromatographyChromatography – separation of – separation of liquidsliquids
Please do now!Please do now!1. Find 3 elements whose symbol is 1. Find 3 elements whose symbol is oneone letter. letter.
What do you notice?What do you notice?
2. Find 3 elements whose symbol is 2. Find 3 elements whose symbol is twotwo letters. letters. What do you notice?What do you notice?
3. Name 3 elements whose symbol is the first two 3. Name 3 elements whose symbol is the first two letters of its name.letters of its name.
4. Name 3 elements whose symbol is different from 4. Name 3 elements whose symbol is different from the first two letters of its name.the first two letters of its name.
5. Find 2 you know are metals and 2 you know are 5. Find 2 you know are metals and 2 you know are gases.gases.
Did you notice...Did you notice...
1. All elements with single letter symbols are 1. All elements with single letter symbols are capitalizedcapitalized
2. Two letter symbols are CAPITAL then 2. Two letter symbols are CAPITAL then smallsmall
3. Aluminum = Al (symbol relates to name)3. Aluminum = Al (symbol relates to name)
4. Some symbols are named after Greek or 4. Some symbols are named after Greek or Latin roots (p. 17 in your book) Latin roots (p. 17 in your book) and next slideand next slide
5. Where are these located on your periodic 5. Where are these located on your periodic table? table?
Some examples:Some examples:
Tin: Sn from the Latin stannumTin: Sn from the Latin stannum
Tungsten: W from the Latin wolframTungsten: W from the Latin wolfram
Lead: Pb from the Latin plumbumLead: Pb from the Latin plumbum
Iron: Fe from the Latin ferrumIron: Fe from the Latin ferrum
Metals, nonmetals, metalloidsMetals, nonmetals, metalloids
METALSMETALS to the left to the left
NONMETALSNONMETALS to the right to the right
METALLOIDSMETALLOIDS the steps (middle) the steps (middle)
Make your own PTMake your own PT
TransitionsTransitions
Inner transitions = Inner transitions = Lanthanides/ActiLanthanides/Actinidesnides
Alkali MetalsAlkali Metals
Alkaline Earth MetalsAlkaline Earth Metals
HalogensHalogens
Noble GasesNoble Gases
BlocksBlocks
GroupsGroups
MetalsMetals
NonmetalsNonmetals
MetalloidsMetalloids
Please do now!Please do now!http://www.chemistry.org/portal/a/c/s/1/acsdisplay.html?DOC=sitetools%5Cperiodic_table.html#
Color all metals Color all metals blueblue..
Color all nonmetals Color all nonmetals greengreen
Trace the “steps” in Trace the “steps” in redred then color all then color all metalloids yellow (use the PT in the back metalloids yellow (use the PT in the back of your text to find the “steps”)of your text to find the “steps”)
Types of atoms:Types of atoms:
MonatomicMonatomic: stand alone, one type of atom: stand alone, one type of atom
DiatomicDiatomic: exist as a double (two); never : exist as a double (two); never found alone in naturefound alone in nature
N, O, F, Cl, Br, I, HN, O, F, Cl, Br, I, H
““The magic 7 plus one”The magic 7 plus one”
What is an What is an alloyalloy??
Metallic mixture of Metallic mixture of two or more two or more elements (at least elements (at least one is a metal)one is a metal)
made by melting made by melting the elements then the elements then mixing and cooling mixing and cooling themthem
HOMOGENEOUSHOMOGENEOUS
What is an What is an alloyalloy??
Some examples:Some examples:
– Brass = copper + zincBrass = copper + zinc
– Bronze = copper + tinBronze = copper + tin
– Steel = several different elementsSteel = several different elements
What is an What is an alloyalloy??
Advantages:Advantages:– properties of alloys are often superior to properties of alloys are often superior to
those properties of their component those properties of their component elementselements
STERLING SILVER-harder and more durable STERLING SILVER-harder and more durable than pure silver but still soft enough to be than pure silver but still soft enough to be made into jewelry and flatwaremade into jewelry and flatware
BRONZE-more easily cast than its part and BRONZE-more easily cast than its part and harder than copperharder than copper
