2The Phases (States) of Matter Solid (s)* definite shape & definite volume* particles are in a regular, geometric pattern or crystalline shape* particles vibrate in fixed positionsLiquid (l)* take shape of container, definite volume* particles can flowGas (g)* expand to completely fill container* no definite shape or volumeNote - Vapor refers to a substance that is not normally a gas.(aq) = Aqueous = the substance is dissolved in water.
3Phases – con’t 4. The phases differ due to differences in the: a) arrangement or distance between their particlesb) attraction between their particles.Solid Liquid Gas
4The Three Classes of Matter: ElementsCompoundsMixturesMatterSubstance Mixtures of Substances(fixed composition) (composition varies)Elements Compounds Heterogeneous Homogeneous(these are homogeneous)Suspensions Solutions
5Models Elements (made of a single kind of atom) Monatomic Element or Diatomic ElementHe H2Compounds(hook different atoms together to show they are chemically combined)Water is a compound (H2O)Mixtures(the different substances aren’t hooked – shows they are physically combined)Mixture ofWater (H2O) & Oxygen (O2)
6Elements 1. Elements are substances composed of atoms that cannot be broken down any further.A particular element contains atoms having the same atomic number.Some examples: Iron (Fe) or Hydrogen (H2)
7Elements – con’tSome elements exist in several different forms.They have different structures & differentproperties. (Allotropes)Example: Forms of solid Carbon
8Elements – con’tExample: Forms of Oxygen gas Most oxygen in the air is O2. This is the odorless gas that sustains life. Ozone is O3. Ozone gas has a sharp odor and damages respiratory tissue.
9Compounds1. Compounds are substances composed of atoms from 2 or more different elements chemically combined in a fixed or definite ratio.2. The compound’s properties are not the same as its component’s original properties.Examples: Water (H2O)Sodium Chloride (NaCl)
10MixturesMixtures are composed of 2 or more different substances physically combined in any ratio.The composition of a mixture is not fixed. For example grape juice may be really sweet or tart.The components of a mixture keep (or retain) their original individual properties.Examples:Raisin Bran, Chex Mix, Koolaid, Italian SaladDressing
11E, C, or M? NH3(g) Br2(l) H2SO4(aq) Cu(s) NaCl(s) NaCl(aq) Answers: C, E, M, E, C, M
12Homogeneous MixturesYou cannot see the different parts because the particles are uniformly or evenly mixed resulting in constant properties throughout that sample. Examples: Kool-Aid, Air, Milk, Saltwater.
13Heterogeneous Mixture You can see visibly different parts because the particles are NOT uniformly mixed.Examples: Soil, Vegetable soup, Trail mix, Lucky charms
14Miscible vs Immiscible Miscible refers to mixtures of liquids that dissolve in each otherExample: water & vinegarImmiscible refers to mixtures of liquids that separate (don’t dissolve)Example: water & oil
15SolutionsA solution is a homogeneous mixture containing a solute dissolved in a solvent.Example: sugar water C12H22O11 (aq)(aq) = aqueous = dissolved in water2. The solute (sugar) is the substance dissolved.3. The solvent (water) does the dissolving.They cannot be separated by filtration.Note: If a solid dissolves, we say it is soluble.
16SuspensionsA suspension is a heterogeneous mixture of an insoluble solid suspended in a liquid.The insoluble solid doesn’t dissolve, it will settle on standing.An example is cornstarch mixed in water.They can be separated by filtration.
17Separation of Mixtures The components in a mixtures can be separated physically - based on differences in properties such as color, density, solubility, etc.Some examples: (see pictures)Filtration (particle size)Chromatography (absorption)Distillation (boiling point)
18FiltrationIn filtration, larger solid particles are separated from smaller liquid particles by passing the mixture through a filter.
19DistillationDistillation uses differences in the boiling points to separate a homogeneous mixture into its components.
20ChromatographySeparation of components of black inkChromatography separates substances in a mixture based on differences in absorption up a strip of paper dipped in a solvent.
21Separation of Compounds Occurs only by chemical reactionExample: Decomposition of water into hydrogen and oxygen gas