Chapter 3 Matter- Properties & Changes

Chapter 3 Learning Targets 3.1  Describe the three states of matter in terms of shape, volume & compressibility. Differentiate between a gas & vapor  Identify the characteristics of a substance Compound, element  Distinguish between physical & chemical properties Physical: extensive & intensive properties 3.2  Describe physical and chemical changes and list examples (indicators) of each.  Apply the Law of the Conservation of Mass to chemical reactions 3.3  Classify mixtures as homogenous or heterogeneous

Ch 3 Homework : #1-3 pg : #1-3 pg : #6-13 pg : #15-16 pg. 83 Chapter Review 3.1: #33-34, & 41 pg : #43 & 46 pg : #60-61 pg. 95 Mixed Review: #82, pg. 96

Matter- Properties & Changes P.O.E. In your notebook write the following headings with a few lines in between: Predict Observe Explain Predict what will happen as the temperature increases from 0 o C to 100 o C. Observe Explain the phase changes of water

3.1 Properties of Matter A.Substances (pure) 1.Substance – material with constant (unchanging) composition a.2 kinds 1)Element – one kind of atom 2)Compound – more than one kind a)Table salt – its always sodium chloride, its composition will never change b)Pure water – always composed of hydrogen & oxygen

3.1 Properties of Matter B.States of Matter: Can distinguish by the way it fills a container 1.Solids (s) – definite shape & volume,when heated a solid expands only slightly, incompressible

3.1 Properties of Matter 2.Liquids (l) – matter that flows, has constant volume & takes the shape of its container, tend to expand when heated, incompressible

3.1 Properties of Matter 3.Gases (g) – flows & takes the shape of its container, but fills entire volume of its container (no definite volume), easily compressed

3.1 Properties of Matter SIDE NOTE – gas & vapor do not mean the same thing… gas – a substance that is naturally room temp. vapor – gaseous state of a substance that is a solid or liquid at room temp.

3.1 Properties of Matter C.Physical Properties of Matter 1.Can be observed or measured w/o changing the sample’s composition. Refers to only that substance

3.1 Properties of Matter 2.Extensive properties - are dependent on the amount of substance present, such as mass, length, or volume. 3.Intensive properties – depends on the nature of the material: a.Malleability b.Ductility c.Density d.Color e.Melting point f. Boiling point g. Crystalline shape h. Refractive index i. Conductivity (heat, light electricity)

3.1 Properties of Matter D.Chemical Properties - the ability of a substance to combine with or change into one or more other substances 1.Iron forming rust 2.Copper turning green in the air

QOD 1.Density is what kind of property? A. atomic B. intensive C. extensive D. dependent 2.What defines a gas? A. Gases have a definite volume and shape B. Gases have a definite volume but take the shape of their container C. Gases have no definite volume or shape D. Gases have a definite shape but no definite volume. A. Gases have a definite volume and shape B. Gases have a definite volume but take the shape of their container C. Gases have no definite volume or shape D. Gases have a definite shape but no definite volume.

3.2 Changes in Matter – Physical Changes A.A change that alters a substance without changing its composition is known as a physical change.physical change 1.Examples: A phase change is a transition of matter from one state to another Boiling, freezing, melting, and condensing all describe phase changes in chemistry.phase change Other examples (or processes) of physical change: Distillation, crystallization

3.2 Changes in Matter – Chemical Changes B.A change that involves one or more substances turning into new substances is called a chemical change (or chemical reaction).chemical change 1.Examples: Decomposing, rusting, exploding, burning, or oxidizing, digesting, fermentation are all terms that describe chemical changes. 2.Always produces a change in properties a.When iron rusts, rust is not attracted to a magnet, but iron is

3.2 Changes in Matter – Conservation of Mass C.The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction, it is conserved.law of conservation of mass 1.The mass of the reactants equals the mass of the products. a. mass reactants = mass products Starting substances New substances formed

3.2 Changes in Matter - Application In a catalytic converter – found in car exhaust systems – carbon monoxide gas (CO) reacts with 16g of oxygen gas (O 2 ) to form 44 g of carbon dioxide gas (CO 2 ). What is the mass of the CO in the catalytic converter? Analyze the problem; known vs. unknown Known: mO 2 = 16 gUnknown: mCO = ? mCO 2 = 44g Solve for unknown: mass reactants = mass products

QOD 1. When one substances turns into another, what kind of change has taken place? A. chemical reaction B. physical reaction C. extensive reaction D. nuclear reaction 2. The law of conservation of mass states that: A.Matter can be created and destroyed. B.Matter can be created but not destroyed. C.The products of a reaction always have a greater mass than the reactants. D.The products of a reaction must have the same mass as the reactants.

3.3 Mixtures of Matter A.A mixture is a combination of two or more pure substances in which each pure substance retains its individual chemical properties.mixture 1.Example: alloy fillings & salad dressing

3.3 Mixtures of Matter – Types of Mixtures B.Heterogeneous Mixtures: a mixture where the individual substances remain distinct. (ex. Salad dressing, wood, granite, concrete, t-bone steak)

3.3 Mixtures of Matter – Types of Mixtures C.Homogeneous Mixtures: a mixture where the composition is constant throughout. 1.Always has a single phase 2.Some are mixtures of more than one material (ex. Fillings) a.Solutions are mixtures. 1)Variable composition (ex. Salt + water) 2)Solute – dissolvee (salt – least) 3)Solvent – dissolver (water – most)

3.3 Mixtures of Matter – Types of Mixtures (table 3.3 pg. 81)

3.3 Mixtures of Matter – Separating Mixtures (pure substances) D.Filtration is a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture.Filtration E.Distillation is a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances. F.Crystallization is a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance.Crystallization

3.3 Mixtures of Matter – Separating Mixtures (pure substances) G.Sublimation - is the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not. H.Chromatography - is a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material.