Ch. 2 Matter and Change Objective: To understand how matter is broken down and the properties we use to classify matter Why: Everything around us is made up of matter. The vocab terms and concepts discussed will be able to be applied in the most common of situations

Describing Matter Extensive Properties: A property that depends on the amount of matter in a sample. – Mass- measure of the amount of matter the object contains – Volume- measure of the space occupied by an object Intensive Properties: A property that depends on the type of matter in a sample Examples?????

States of Matter Solid- form of matter that has a definite shape and volume Liquid- form of matter with a definite volume but no definite shape. Shape of container Gas- form of matter with no definite shape and no definite volume Why have you never heard someone say “water gas”, instead they say “water vapor”? Vapor- describes the gaseous state of a substance that is generally a liquid or a solid at room temp.

DETERMING STATE OF MATTER KINETIC-MOLECULAR THEORY – ALL MATTER IS MADE UP OF TINY PARTICLES THAT ARE IN CONSTANT MOTION – THE PARTICLES IN A SOLID ARE MOVING SLOWER THAN THE PARTICLES IN A GAS. How do the particles “move”?

TEMPERATURE MEASURE OF THE AVERAGE KINETIC ENERGY OF PARTICLES IN MATTER. – FAHRENHEIT, CELSIUS, AND KELVIN SCALES – FAHRENHEIT AND CELSIUS ARE BASED ON THE BOILING AND FREEZING POINT OF WATER. (Fahrenheit is more precise) – KELVIN IS BASED ON ABSOLUTE ZERO (THE THEORETICAL POINT AT WHICH ALL MOLECULAR MOTION CEASES)

CHEMISTRY ALSO STUDIES ENERGY ENERGY IS THE CAPACITY TO DO WORK OR TO PRODUCE HEAT FORMS OF ENERGY – KINETIC ENERGY: ENERGY OF MOTION – POTENTIAL ENERGY: ENERGY OF POSITION (STORED ENERGY)

ENERGY MEASURING ENERGY – CALORIE : UNIT OF ENERGY ONE CALORIE IS THE AMOUNT OF HEAT NECESSARY TO RAISE ONE GRAM OF WATER ONE DEGREE CELSIUS (1cal = 1g HOH X 1 o C ) Big “C” and Little “c” calories – The energy stored in food is given a value in BIG “C” calories (written “Calorie” as opposed to “calorie”) – BIG “C” Calorie = 1000 little ”c” calories (kilocalories) CALORIMETER

Joule – THE SI UNIT OF ENERGY IS THE …… Joule (J) Joule (J) – A JOULE IS EQUIVALENT TO THE ENERGY REQUIRED TO LIFT AN APPLE THROUGH ONE METER. – 1 cal = J

Conservation of Mass During any chemical reaction, the mass of the products is always equal to the mass of the reactants – Mass is neither created nor destroyed

Identifying Substances Substance-matter that has a uniform and definite composition – Every sample of a given substance has identical intensive properties Same composition Pure

Compound vs. Element Element- simplest form of matter that has a unique set of properties Examples???? Compound-Substance that contains two or more elements chemically combined in a fixed proportion Examples???? Compounds can be broken down into simpler substances by chemical means, but elements cannot

Properties of Compounds A compounds properties are different from their component elements – Example: H 2 O - liquid that puts out fire, – Oxygen is a gas that supports fire – Hydrogen is a gas that will burn in the presence of Oxygen NaCl- white solid – Sodium - soft gray metal – Chlorine - pale yellow green poisonous gas

Classifying Mixtures Mixture- a physical blend of two or more components – Examples?????? Heterogeneous Mixture- composition is not uniform throughout mixture – Chicken Noodle Soup, Salad, concrete Homogeneous Mixture- composition is uniform throughout mixture Solution – Solute- dissolved particles in a solution – Solvent- the dissolving medium in a solution – - Vinegar, stainless steal Phase- any part of a sample with uniform composition and properties

Lets Play…….Name That Mixture With your team, tell me If the following are heterogeneous or homogeneous mixtures….

LOOK AROUND YOU

Separating Mixtures Mixtures can be separated based on differences in physical properties Filtration-process to separate a solid from the liquid in a heterogeneous mixture Distillation- a liquid is boiled to produce a vapor that is then condensed into a liquid – Evaporation- a liquid is boiled to produce a vapor that escapes into the atmosphere and leaves behind the dissolved solid

Physical vs. Chemical properties of a substance Physical Property- Quality or condition of a substance that can be observed or measured w/o changing the substances composition – Ex. Hardness, conductivity, malleability Chemical Property - The ability of a substance to undergo a specific chemical change – Ex, reactivity, enthalpy of formation With you team put the following properties into the correct category. When you believe your team is finished put your answers on the board. Hardness Ability to form Rust Boiling Point Conductivity State Density Reactivity Toxicity Flammability Color Melting Point Malleability

Chemical vs. Physical Change Physical Change- some properties of a material change, but the composition of the material does not change – Reversible or irreversible Chemical Change - change that produces matter with a different composition than the original matter – Chemical reaction- 1 or more substances changes into 1 or more new substances. – Reactant and Product

4 Clues to Chem. Change 1. Transfer of Energy 2. Change in color 3. Production of a Gas 4. Formation of a Precipitate – A solid that is formed and settles out from two liquid solutions