? THUS FAR WE HAVE REVIEWED MATTER AS PURE SUBSTANCES. NOW LETS DISCOVER MATTER AS MIXTURES MATTER PURE SUBSTANCE ELEMENT COMPOUND Carbon (C) H2O MIXTURE ?

Classification Matter Has mass and takes up space Mixture Variable Composition Substance Define composition Compound Two or more kinds of atoms Homogeneous Evenly mixed Heterogeneous Unevenly mixed Element One kind of atom

Solution Process A mixture is formed by two or more elements or compounds that are physically mixed together but not chemically joined. example: salt and pepper Mixture can be: Homogeneous Evenly mixed Heterogeneous Unevenly mixed

The two types of Mixtures : Classifying mixtures Mixture is formed by two or more elements or compounds that are physically mixed together but not chemically joined. example: salt and pepper The two types of Mixtures : 1) HOMOGENEOUS 2) HETEROGENEOUS Homogeneous Evenly mixed Heterogeneous Unevenly mixed

The Two Types of Mixture 1. Solution is a homogeneous mixture in which one substances is dissolved in another substance. It consists of a solute and solvent. Solute is the substance dissolved in the solution. Solvent is the substance in which the solute is dissolved When sugar, a solute and water a solvent are mixed, a water sugar solution is formed.

The Two Types of Mixture (Cont.) 2. Suspension is a mixture of water with non-dissolve material Example sand and water

Solute is the substance dissolved in the solution Particles may be ions, atoms, or molecules Solvent is the substance in which the solute is dissolved

Heterogeneous Mixture (Suspension) Homogeneous Mixture (Solution) Mixtures Summary Heterogeneous Mixture (Suspension) Homogeneous Mixture (Solution) Not evenly mixed Evenly mixed Individual components retain their own properties Properties of combined components are usually different than those of each component Individual components can be easily seen Individual components can not be easily seen Can be easily separated Not as easily separated Ex.: salt & pepper mix, rocks, cereal, bag of assorted candy Ex. salt-water solution, tea, kool-Aid drink

Solubility Solubility is the amount of a substance that can dissolve in 100 grams of solvent at a given time. The ability of a solvent to dissolve a solute depends on temperature and molecular structure. Like dissolve like: When the temperature of a liquid increases, The solubility of the solvent increases.

Classifying Matter Matter Pure Substances Mixtures Tea, kool-aid He, O Review: How matter is classified Matter Pure Substances Mixtures Homogeneous Heterogeneous Elements Compounds Rocky Road ice cream, muddy water Tea, kool-aid He, O H2O, NaCl 10

Practice Problems Tossed salad Salt water Kool-aid Muddy water Determine whether each is a heterogeneous or homogeneous mixture: Tossed salad Salt water Kool-aid Muddy water OJ with pulp 6. Tea 7. Banana nut bread 8. Pizza 9. Blood 10. Brass Answers: 1. He 2. Ho 3. Ho 4. He 5. He 6. Ho 7. He 8. He 9. He 10. Ho Return to index

More review Classify the following substances as: Pure substance, heterogeneous mixture, or homogeneous mixture Gatorade Homogenous mixture Fruit Loops Heterogeneous mixture Pure substance Gasoline Dirt Sugar Crystals Pure Substance Air Homogeneous mixture Granite Return to index

REVIEW We are studying CHEMISTRY, the study of ________and how it ________. Matter is anything that has___ and takes up ___. ___ are the basic building blocks of matter. Matter can be classified as either a ___ or a ___. Substances are either ___ or ___. Answers: 1. matter, changes 2. mass, space 3. atoms 4. pure substance, mixture 5. elements, compounds Return to index

MATTER AS MIXTURES Mixtures are combinations of 2 or more substances where each substance retains its individual properties. HOW ARE MIXTURES LIKE COMPOUNDS? THEY ARE MADE FROM TWO OR MORE SUBSTANCES HOW ARE MIXTURES DIFFERENT FROM COMPOUNDS? MIXTURES DO NOT FORM CHEMICAL BONDS.

is HOMOGENEOUS …a mixture that is the same throughout. A homogeneous mixture has a composition and properties that are identical regardless of the sample is Ways to identify a homogeneous mixture: HOMOGENEOUS one phase uniformly mixed won’t settle out small particles A SOLUTION is another name for a homogeneous mixture

HETEROGENEOUS is … a mixture that is visibly different throughout. Heterogenous mixtures have a composition and properties that differ in any given sample. not uniformly mixed more than one phase will settle out larger particles Ways to identify a heterogeneous mixture: HETEROGENEOUS

HETEROGENEOUS MIXTURES There are special types of heterogeneous mixtures: Suspensions-appear uniform when mixed but settle out. Chocolate Quik Muddy water Pulpy oj Oil & Vinegar dressing Colloids-appear uniform but they do not settle out. However, their particles are too large to be classified as a homogeneous solution. Gelatin Smoke Fog mayonnaise

Now, lets put it all together and determine how to tell substances (compounds and elements) from mixtures. Pure Substances Made of either elements or compounds that are chemically bonded. Cannot be separated by physical means. When combined they take on new properties different from the original elements. Examples: Glucose: C6H12O6 Table Salt: NaCl Oxygen Gas: O2 Carbon Dioxide CO2 Mixtures: Two or more substances mixed together but not chemically combined. Tea = Crushed Leaf + H2O Rocks = minerals + sediments + organic matter Sugar Water = Sugar + H2O Each component retains its own identity; it does not change into something else. Can be separated by physical means Examples: Sweet tea Trail mix Air (O2, N2, CO2, Ar)

Elements, Compounds, and Mixtures Two types of atoms evenly mixed Two types of atoms chemically combined One type of atom Two types of atoms mixed An element A solution A compound A mixture Two of the descriptions to the right apply to each bottle below. Determine the appropriate descriptions. hydrogen atoms oxygen atoms hydrogen atoms d & h b & g c & e a & f 1_______ 2_______ 3_______ 4_______ Return to Index