Classification of Matter This well-known molecule is a compound because it contains more than one element. A molecule but not a compound Ozone, O 3, is not a compound because it contains only a single element. Ordinary solid salt is a compound but not a molecule. It is built from interpenetrating lattices of sodium and chloride ions that extend indefinitely.

MATTER Can it be physically separated? Homogeneous Mixture (solution) Heterogeneous MixtureCompoundElement MIXTUREPURE SUBSTANCE yesno Can it be chemically decomposed? noyes Is the composition uniform? noyes ColloidsSuspensions Courtesy Christy Johannesson

Elements only one kind of atom; atoms are bonded it the element is diatomic or polyatomic Compounds two or more kinds of atoms that are chemically bonded substance with definite makeup and properties Mixtures two or more substances that are physically mixed two or more kinds of and Both elements and compounds have a definite makeup and definite properties. Packard, Jacobs, Marshall, Chemistry Pearson AGS Globe, page (Figure 2.4.1)

Matter Flowchart Examples: –graphite –pepper –sugar (sucrose) –paint –soda Courtesy Christy Johannesson element hetero. mixture compound solution homo. mixture hetero. mixture

Pure Substances Element –composed of identical atoms –EX: copper wire, aluminum foil Courtesy Christy Johannesson

Pure Substances Compound –composed of 2 or more elements in a fixed ratio –properties differ from those of individual elements –EX: table salt (NaCl) Courtesy Christy Johannesson

Pure Substances Law of Definite Composition –A given compound always contains the same, fixed ratio of elements. Law of Multiple Proportions –Elements can combine in different ratios to form different compounds. Courtesy Christy Johannesson

Pure Substances For example… Two different compounds, each has a definite composition. Carbon, C Oxygen, O Carbon monoxide, CO Carbon, C Oxygen, O Oxygen, O Carbon dioxide, CO 2 Courtesy Christy Johannesson

Mixtures Variable combination of two or more pure substances. HeterogeneousHomogeneous Courtesy Christy Johannesson

Mixtures Solution –homogeneous –very small particles –no Tyndall effect Tyndall Effect –particles don’t settle –EX: rubbing alcohol Courtesy Christy Johannesson

Mixtures Colloid –heterogeneous –medium-sized particles –Tyndall effect –particles don’t settle –EX: milk Courtesy Christy Johannesson

Mixtures Suspension –heterogeneous –large particles –Tyndall effect –particles settle –EX: fresh-squeezed lemonade Courtesy Christy Johannesson

Mixtures Examples: –mayonnaise –muddy water –fog –saltwater –Italian salad dressing Courtesy Christy Johannesson colloid suspension colloid solution suspension

Classification of Matter Materials Homogeneous Heterogeneous mixture Homogeneous mixture Substance ElementCompoundSolutionMixture Specific / General Order / Disorder Smoot, Smith, Price, Chemistry A Modern Course, 1990, page 43

Classification of Matter MATTER (gas. Liquid, solid, plasma) PURE SUBSTANCES MIXTURES HETEROGENEOUS MIXTURE HOMOGENEOUS MIXTURES ELEMENTSCOMPOUNDS Separated by physical means into Separated by chemical means into Kotz & Treichel, Chemistry & Chemical Reactivity, 3 rd Edition, 1996, page 31

Classification of Matter uniform properties? fixed composition? chemically decomposable? no yes hetero- geneous mixture solution element compound

Elements, Compounds, and Mixtures (a) an element (hydrogen) (b) a compound (water) (c) a mixture (hydrogen and oxygen) (d) a mixture (hydrogen and oxygen) Dorin, Demmin, Gabel, Chemistry The Study of Matter, 3 rd Edition, 1990, page 68 hydrogen atoms hydrogen atoms oxygen atoms

Elements, Compounds, and Mixtures (a) an element (hydrogen) (b) a compound (water) (c) a mixture (hydrogen and oxygen) (d) a mixture (hydrogen and oxygen) Dorin, Demmin, Gabel, Chemistry The Study of Matter, 3 rd Edition, 1990, page 68 hydrogen atoms hydrogen atoms oxygen atoms

Mixture vs. Compound Mixture Fixed Composition Bonds between components Can ONLY be separated by chemical means Variable Composition No bonds between components Can be separated by physical means Alike Different Contain two or more elements Can be separated into elements Involve substances Compound Different 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 + Cl 2 Mixtures retain their individual properties. –e.g. Salt water is salty and wet

Classifying Matter Keys Classifying Matter

Diatomic Elements, 1 and 7 H2H2 N2N2 O2O2 F2F2 Cl 2 Br 2 F2F2

Products made from Sulfur

Magazines and printing papers Writing and fine papers Wrapping and bag papers Sanitary and tissue papers Absorbent papers Rayon Cellophane Carbon Tetrachloride Ruber processing chemicals Containers and boxes Newsprint Pulp for rayon and film PULP 3% OTHER 3% NONACID 12% Insecticides Fungicides Rubber vulcanizing Soil sulfur Specialty steels Magnessium Leather processing Photography Dyestuffs Bleaching Soybean extraction Aluminum reduction Paper sizing Water treatment Pharmaceuticals Insecticides Antifreeze Superphosphates Ammonium phosphate Ammonium sulfate Mixed fertilizers Autos Appliances Tin and other containers Galvanized products Explosives Nonferrous metals Synthetic rubber Storage batteries Textile finishing Tire cords Viscose textiles Acetate textiles Blended fabrics Cellophane Photographic film Paints and enamels Linoleum and coated fabrics Paper Printing inks Aviation Gasoline Lubricants Other Refinery products SULFURIC ACID 88% CARBON DISULFIDE 3% GROUND & DEFINED 3% IRON & STEEL 1% PETROLEUM 2% CHEMICAL 17% OTHER INDUSTRIES 6% RAYON & FILM 3% TITANIUM AND OTHER PIGMENTS 5% Synthetic detergents Feed additives Anti-knock gasoline Synthetic resins Protective coating Dyestuffs Oil well acidizing Petroleum catalysts

Rhombic sulfur –“Brimstone” (when molten) –Polyatomic (S 8 ) –Forms SO 2 Amorphous sulfur –(without shape) Sulfur The sudden cooling of  -sulfur produces amorphous sulfur.

Amorphous (Glass) Crystalline

The Haber Process

Matter Substance Definite composition (homogeneous) Substance Definite composition (homogeneous) Element (Examples: iron, sulfur, carbon, hydrogen, oxygen, silver) Element (Examples: iron, sulfur, carbon, hydrogen, oxygen, silver) Mixture of Substances Variable composition Mixture of Substances Variable composition Compound (Examples: water. iron (II) sulfide, methane, Aluminum silicate) Compound (Examples: water. iron (II) sulfide, methane, Aluminum silicate) Homogeneous mixture Uniform throughout, also called a solution (Examples: air, tap water, gold alloy) Homogeneous mixture Uniform throughout, also called a solution (Examples: air, tap water, gold alloy) Heterogeneous mixture Nonuniform distinct phases (Examples: soup, concrete, granite) Heterogeneous mixture Nonuniform distinct phases (Examples: soup, concrete, granite) Chemically separable Physically separable

The Organization of Matter MATTER PURE SUBSTANCES HETEROGENEOUS MIXTURE HOMOGENEOUS MIXTURES ELEMENTSCOMPOUNDS Physical methods Chemical methods Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 41

Top Ten Elements in the Universe Percent Element (by atoms) 1.Hydrogen Helium Oxygen Carbon Neon Iron Nitrogen Silicon Magnesium Sulfur 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 Oxygen Helium Water vapor Water vapor Neon Carbon dioxide Carbon dioxide 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 two hydrogen atoms and one oxygen atom: Argon consists of individual argon atoms: Carbon dioxide consists of molecules consisting of two oxygen atoms and one carbon atom: Neon consists of individual neon atoms: Helium consists of individual helium atoms: N2N2 O2O2 H2OH2O Ar CO 2 Ne He Zumdahl, Zumdahl, DeCoste, World of Chemistry  2002, page 35

Reviewing Concepts Reviewing Concepts Classifying 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?