Classification of Matter
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Transcript of Classification of Matter
Classification of Matter
Use to make foldableThe terms in red are your voc.
terms.
Pure Substances
• Pure Substance that cannot be broken down into any other substances by chemical or physical means
Gold - element Manganese Dioxide - compound
Pure Substance• Element
– composed of identical atoms– EX: copper wire, aluminum foil
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Pure Substances
• Compound– composed of 2 or more elements
in a fixed ratio
– properties differ from those of individual elements
– Chemical bonds hold the elements together
– EX: table salt (NaCl)
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Pure Substances - FYILaw of Definite CompositionLaw of Definite Composition
– A given compound always contains the same, fixed ratio of elements.
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Two different compounds, each has a definite composition
Molecules
• Groups of two or more atoms bound by chemical bonds
• Can be two of the same element
Chemical Formula-Extra Info
• Shows the compound and the ratio of atoms
Diatomic Elements, 1 and 7H2
N2 O2 F2
Cl2
Br2
F2
Matter Flowchart
Examples:– graphite
– pepper
– sugar (sucrose)
– paint
– soda
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element
hetero. mixture
compound
solution homo. mixture
hetero. mixture
Classification of Matter
uniformproperties?
fixedcomposition?
chemicallydecomposable?
no
no
no
yes
hetero-geneousmixture
solution
element
compound
http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld003.htm
Elements
only one kindof atom; atomsare bonded itthe element
is diatomic orpolyatomic
Compounds
two ormore kindsof atomsthat arebonded
substancewith
definitemakeup
andproperties
Mixtures
two or moresubstances
that arephysically
mixed
two ormore
kinds ofand
Both elements and compounds have a definite makeup and definite properties.
Packard, Jacobs, Marshall, Chemistry Pearson AGS Globe, page (Figure 2.4.1)
Mixtures Variable combination of two or more
pure substances. Each keep individual properties
Homogeneous- Evenly Mixed cannot see different parts. (Same)
Heterogeneous – Can see different parts (different)
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Tyndall Effect• The scattering of light by particlesin a mixture
• http://www.youtube.com/watch?v=gheuYqQ6phE&feature=related
Mixtures
Solution– homogeneous– very small particles– no Tyndall effect– particles don’t settle
– EX: – rubbing alcohol (ethyl alcohol
and water)– Air (nitrogen and oxygen)
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MixturesColloid
– heterogeneous– medium-sized particles– Tyndall effect– particles don’t settle– Particles scatter light– EX:
• Milk• Clouds• Smoke• mayo
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Mixtures
Suspension– heterogeneous– large particles– Tyndall effect– particles settle– EX:
• fresh-squeezed lemonade
• Sand in water
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Mixtures
Examples:– mayonnaise
– muddy water
– fog
– saltwater
– Italian salad dressing
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colloidsuspensioncolloid
solution
suspension
Elements, Compounds, and Mixtures
(a)an element(hydrogen)
(b)a compound(water)
(c)a mixture(hydrogen and oxygen)
(d)a mixture(hydrogenand oxygen)
Dorin, Demmin, Gabel, Chemistry The Study of Matter , 3rd Edition, 1990, page 68
hydrogenatoms hydrogen
atoms
oxygen atoms
MATTERCan it be physically
separated?
Homogeneous Mixture
(solution)
Heterogeneous Mixture Compound Element
MIXTURE PURE SUBSTANCE
yes no
Can it be chemically decomposed?
noyesIs the composition uniform?
noyes
Colloids Suspensions
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Classification of Matter
MATTER(gas. Liquid,
solid, plasma)
PURESUBSTANCES MIXTURES
HETEROGENEOUSMIXTURE
HOMOGENEOUSMIXTURESELEMENTSCOMPOUNDS
Separated by
physical means into
Separated by
chemical means into
Kotz & Treichel, Chemistry & Chemical Reactivity, 3rd Edition , 1996, page 31
Matter
SubstanceDefinite composition
(homogeneous)
Element(Examples: iron, sulfur,
carbon, hydrogen,oxygen, silver)
Mixture ofSubstances
Variable composition
Compound(Examples: water.
iron (II) sulfide, methane,Aluminum silicate)
Homogeneous mixtureUniform throughout,also called a solution
(Examples: air, tap water,gold alloy)
Heterogeneous mixtureNonuniform
distinct phases(Examples: soup, concrete, granite)
Chemicallyseparable
Physicallyseparable
Classification of Matter
Mixture vs. Compound
Mixture
FixedComposition
Bonds between
components
Can ONLY beseparated by
chemical means
VariableComposition
No bondsbetween
components
Can beseparated by
physical means
Alike Different
Contain two or more
elements
Can beseparated
intoelements
Involvesubstances
Compound
Different
Topic Topic
Compounds vs. Mixtures
• Compounds have properties that are uniquely different from the elements from which they are made. – A formula can always be written for a compound– e.g. NaCl Na + Cl2
• Mixtures retain their individual properties.– e.g. Salt water is salty and wet
Top Ten Elements in the Universe
Percent
Element (by atoms) 1. Hydrogen 73.92. Helium 24.03. Oxygen 1.14. Carbon
0.465. Neon 0.136. Iron 0.117. Nitrogen
0.0978. Silicon 0.0659. Magnesium 0.05810.Sulfur 0.044
A typical spiral galaxy(Milky Way is a spiral galaxy)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 26
The Composition of Air
Air
Nitrogen
OxygenHelium
Watervapor
Neon
Carbondioxide Argon
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 34
Chart Examining Some Components of Air
Nitrogen consists of molecules consisting of two atoms of nitrogen:
Oxygen consists of molecules consisting of two atoms of oxygen:
Water consists of molecules consisting of twohydrogen atoms and one oxygen atom:
Argon consists of individual argon atoms:
Carbon dioxide consists of molecules consistingof two oxygen atoms and one carbon atom:
Neon consists of individual neon atoms:
Helium consists of individual helium atoms:
N2
O2
H2O
Ar
CO2
Ne
HeZumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 35
Reviewing ConceptsReviewing ConceptsClassifying Matter
• Why does every sample of a given substance have the same properties?
• Explain why the composition of an element is fixed.
• Describe the composition of a compound.• Why can the properties of a mixture vary?• On what basis can mixtures be classified as
solutions, suspensions, or colloids?
Separating a Mixture
Separating a Mixture
• Chromatography - To separate different colored dyes. The dyes travel up the chromatography paper at different distances before they cannot remain in solution. The more soluble dyes move further up than the less soluble ones, hence separating from each other.
Separating a Mixture
• Distillation - to separate and collect a liquid from a solution of a soluble solid. The solution is heated in a flask until the liquid boils. The vapor produced passes into the condenser where it is cooled and condenses to a liquid. The pure liquid (distillate) is collected in a beaker.
Separating a Mixture
Evaporation – This method is suitable to separate a soluble solid from a liquid. If the solution is heated, the liquid evaporates leaving the solid behind.
Separating a Mixture
Fractional Distillation - This is a special type of distillation used to separate a mixture of liquids. Different liquids boil at different temperatures. When heated, they boil off and condense at different times. The apparatus features a fractionating column, which ensures that only the liquid boils at its boiling point will pass into the condenser.
Separating a Mixture
Filtration – To separate an insoluble solid from a liquid. The solid remains in the filter paper and the liquid goes through the paper into the beaker.
Separating a Mixture
• Click for link – Setup for each type