more about matter. physical vs. chemical properties physical properties physical properties observed...
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More About MatterMore About Matter
Physical vs. Chemical Physical vs. Chemical PropertiesProperties
Physical PropertiesPhysical Properties Observed without changing identity of substance.Observed without changing identity of substance.
Ex: color, hardness, density, odor, malleability, ductility, MP temp.Ex: color, hardness, density, odor, malleability, ductility, MP temp.
Chemical PropertiesChemical Properties Observed during chemical changesObserved during chemical changes
Ex: flammable, explosive, corrosive, rusts, decomposesEx: flammable, explosive, corrosive, rusts, decomposes
Chemical vs. Physical Changes Chemical vs. Physical Changes
Physical ChangePhysical Change Does not alter chemical composition. Does not alter chemical composition. Substance still has same chemical formula.Substance still has same chemical formula.
Ex: bend, cut, grind, dissolve, undergo a phase changeEx: bend, cut, grind, dissolve, undergo a phase change
Chemical ChangeChemical Change Chemical composition changes as a reaction occurs.Chemical composition changes as a reaction occurs. New products formed.New products formed.
Ex: cook food, sour milk, burn wood, explode dynamiteEx: cook food, sour milk, burn wood, explode dynamite
What Type of Change? What Type of Change?
What Type of Change?What Type of Change?
HH22O(s) O(s) → H→ H22O(l)O(l)
2H2H22O (l) → 2HO (l) → 2H22(g) + O(g) + O22(g)(g)
NaCl(s) → NaCl(aq)NaCl(s) → NaCl(aq)
CHCH44(g) + O(g) + O22(g) → CO(g) → CO22(g) + H(g) + H22O(g)O(g)
Is it Chemical or Physical?Is it Chemical or Physical? Sometimes it is possible to determine a Sometimes it is possible to determine a
chemical change using the naked eye.chemical change using the naked eye.
Things to look for:Things to look for: Gas bubbles produced, unusual color change, Gas bubbles produced, unusual color change,
new odor produced, precipitate formsnew odor produced, precipitate forms
PrecipitatePrecipitate: an insoluble solid that forms : an insoluble solid that forms when two solutions are mixed.when two solutions are mixed.
Types of MatterTypes of Matter
Pure Substance vs. MixturesPure Substance vs. Mixtures
Pure SubstancesPure Substances
ElementsElements
• Made up of atoms of one specific typeMade up of atoms of one specific type
• Have specific physical and chemical properties.Have specific physical and chemical properties.
• Cannot be brokenCannot be broken down by chemical reactions down by chemical reactions
• Ex: Fe, K, Na, SiEx: Fe, K, Na, Si
CompoundsCompounds
Two or more different elements chemicallybonded together.
Have different chemical and physical propertiesthan elements that make them up.
Definite fixed proportions by mass.
• Ex: CEx: C66HH1212OO66, MgCl, MgCl22, CO, CO22, NaCl, NaCl
MixturesMixtures
MixturesMixtures
Two or more pure substances Two or more pure substances physically combinedphysically combined..
Mixtures can be solid, liquid or gaseous.Mixtures can be solid, liquid or gaseous.
Composition Not FixedComposition Not Fixed
Composition of a mixture is NOT FIXEDComposition of a mixture is NOT FIXED..Can vary depending on how much of each Can vary depending on how much of each component is added.component is added.
Retaining Their PropertiesRetaining Their Properties
Substances in Substances in mixtures mixtures retain their retain their own propertiesown properties..
Ex: Iron filings (Fe) Ex: Iron filings (Fe) and sand (SiOand sand (SiO22))
Even if mixed the iron Even if mixed the iron retains its magnetic retains its magnetic propertiesproperties
ClipsClips
Mixtures vs. Pure SubstancesMixtures vs. Pure Substances
https://www.youtube.com/watch?v=88MBCyiaPSM
Types of MixturesTypes of Mixtures
Homogeneous MixturesHomogeneous Mixtures
Components are Components are distributed uniformlydistributed uniformly at the molecular at the molecular level.level.
All true All true solutionssolutions are are homogeneous.homogeneous.
Aqueous = Aqueous = (aq)(aq)
dissolved in water or dissolved in water or “in solution”“in solution”
If you see If you see (aq)(aq) it is a it is a homogeneous mixturehomogeneous mixture
Ex: NaCl (aq) Ex: NaCl (aq)
Heterogeneous MixturesHeterogeneous Mixtures
Components are Components are not uniformly not uniformly distributeddistributed at the at the molecular level.molecular level.
Colloids and Colloids and suspensions are suspensions are included in this included in this category.category.
How to Tell if a True SolutionHow to Tell if a True Solution
Tyndall EffectTyndall Effect Suspensions and colloids have larger particles that Suspensions and colloids have larger particles that
will scatter a beam of light. In a true solution the light will scatter a beam of light. In a true solution the light will not be scatteredwill not be scattered
Techniques to Separate Techniques to Separate MixturesMixtures
Separating MixturesSeparating Mixtures
Components Components retain their own propertiesretain their own properties, , so use these properties to separate them.so use these properties to separate them.
Ex: density, particle size differences, solubility Ex: density, particle size differences, solubility differences, BP temperature, magnetic propertiesdifferences, BP temperature, magnetic properties
FiltrationFiltration
Ex: Separate water & sandEx: Separate water & sand
Can be used to separate Can be used to separate heterogeneous mixturesheterogeneous mixtures
Technique Technique cannotcannot be used be used to separate components of to separate components of solutionssolutions
Separatory FunnelSeparatory Funnel
Ex: Separate oil and Ex: Separate oil and waterwater
What type of mixture?What type of mixture?
EvaporationEvaporation
Ex: Separate sugar Ex: Separate sugar from waterfrom water
What type of mixture?What type of mixture?
ChromatographyChromatography
Solvent runs up paper and Solvent runs up paper and components separate out components separate out along length of paper along length of paper depending on level of depending on level of attraction to solvent.attraction to solvent.
Ex: Separate different types Ex: Separate different types of chlorophyllof chlorophyll
DistillationDistillation
Separates two or more Separates two or more liquids, due to liquids, due to differences in boiling differences in boiling point temppoint temp. .
Ex: Separate alcohol Ex: Separate alcohol and waterand water
What type of mixture?What type of mixture?
ClipsClips
Separating MixturesSeparating Mixtureshttp://youtu.be/fJXBlfwB_Nwhttp://youtu.be/fJXBlfwB_NwDistillationDistillationhttp://youtu.be/tcJXGIJA9Wohttp://youtu.be/tcJXGIJA9Wo
Density CalculatingDensity Calculating
DensityDensity Because all matter has mass and volume, all Because all matter has mass and volume, all
matter has density.matter has density.
No matter the size of the sample, the density No matter the size of the sample, the density doesn’t change.doesn’t change.
It is a physical property.It is a physical property.
See Reference Table S for the density of elements.See Reference Table S for the density of elements.
D D = = MMVV https://www.youtube.com/https://www.youtube.com/
watch?v=GnBQ6vIutDMwatch?v=GnBQ6vIutDM
Density of WaterDensity of Water
Density of Pure Water = 1.0 g/mlDensity of Pure Water = 1.0 g/ml
If a substance has a density greater than water it If a substance has a density greater than water it will sink, if not it will float.will sink, if not it will float.
When you dissolve a substance in water it When you dissolve a substance in water it makes it more dense.makes it more dense.
http://youtu.be/7xGo-HPGKmYhttp://youtu.be/7xGo-HPGKmY
Measuring Density (D = M/V)Measuring Density (D = M/V)
MassMass Measured on a Measured on a
scale, often you scale, often you need to use a need to use a weighing dish or a weighing dish or a beaker.beaker.
VolumeVolume Can be measured Can be measured
in different ways.in different ways. For solids the For solids the
method of method of water water displacementdisplacement is is often used.often used.
Density columnDensity columnhttp://youtu.be/-CDkJuo_LYshttp://youtu.be/-CDkJuo_LYsCoke vs Diet cokeCoke vs Diet cokehttp://youtu.be/5HCmRCGv37shttp://youtu.be/5HCmRCGv37s
Cool ClipsCool Clips
Chemical Reactions (Bill Nye)Chemical Reactions (Bill Nye)http://youtu.be/1MiVyBHQmJkhttp://youtu.be/1MiVyBHQmJkhttp://youtu.be/66kuhJkQCVMhttp://youtu.be/66kuhJkQCVMSteve Spangler (clock reactions)Steve Spangler (clock reactions)http://youtu.be/BqeWpywDuiYhttp://youtu.be/BqeWpywDuiYDiet Coke and MentosDiet Coke and Mentoshttp://youtu.be/9vk4_2xboOEhttp://youtu.be/9vk4_2xboOE