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Matter & Its Properties

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1 Matter & Its Properties
Ch 1: Lesson 3 Honors Chemistry K. Davis

2 Matter Matter – anything that has mass and takes up space
Everything around us Chemistry – the study of matter and the changes it undergoes

3 Substances Atoms: the building blocks of all matter
Ions: atoms that become negatively or positively charged Element: matter containing only one type of atom; ex. hydrogen and oxygen

4 Four States of Matter Solids particles vibrate but can’t move around
fixed shape fixed volume incompressible

5 Four States of Matter Liquids
particles can move around but are still close together variable shape fixed volume Virtually incompressible

6 Four States of Matter Gases
particles can separate and move throughout container variable shape variable volume Easily compressed Vapor = gaseous state of a substance that is a liquid or solid at room temperature

7 Four States of Matter Plasma
particles collide with enough energy to break into charged particles (+/-) gas-like, variable shape & volume stars, fluorescent light bulbs, TV tubes

8 Four States of Matter

9 Physical Properties Physical Property
can be observed without changing the identity of the substance

10 Physical Properties Physical properties can be described as one of 2 types: Extensive Property depends on the amount of matter present (example: length) Intensive Property depends on the identity of substance, not the amount (example: scent)

11 Intensive Physical Properties
The intensive physical properties for a sample of a pure substance remain constant. ex. pure water- always a colorless liquid that boils at 100ºC at sea level; doesn’t matter if you have 10 mL or 1 L Melting and boiling point are examples of these constant physical properties. can be used to help identify a substance

12 Extensive vs. Intensive
Examples: boiling point volume mass density conductivity intensive extensive

13 Density – a physical property
Derived units = Combination of base units Volume (m3 or cm3 or mL) length  length  length Or measured using a graduated cylinder 1 cm3 = 1 mL 1 dm3 = 1 L Density (kg/m3 or g/cm3 or g/mL) mass per volume D = M V

14 Density Mass (g) Volume (cm3)

15 Density V = 825 cm3 M = DV D = 13.6 g/cm3 M = (13.6 g/cm3)(825cm3)
An object has a volume of 825 cm3 and a density of 13.6 g/cm3. Find its mass. GIVEN: V = 825 cm3 D = 13.6 g/cm3 M = ? WORK: M = DV M = (13.6 g/cm3)(825cm3) M = 11,220 g M = 11,200 g

16 Density D = 0.87 g/mL V = M V = ? M = 25 g V = 25 g 0.87 g/mL
A liquid has a density of 0.87 g/mL. What volume is occupied by 25 g of the liquid? GIVEN: D = 0.87 g/mL V = ? M = 25 g WORK: V = M D V = 25 g 0.87 g/mL = mL V = 29 mL

17 Chemical Properties Chemical Property
describes the ability of a substance to undergo changes in identity

18 Physical vs. Chemical Properties
Examples: melting point flammable density magnetic tarnishes in air physical chemical

19 Physical Changes Physical Change
changes the form of a substance without changing its identity properties remain the same Ex: cutting a sheet of paper, breaking a crystal, all phase changes

20 Some Physical Changes Boiling Condensation Dissolving Evaporation
Freezing Melting Sublimation

21 Phase Changes – Physical
Evaporation = Condensation = Melting = Freezing = Sublimation = Liquid -> Gas Gas -> Liquid Solid -> Liquid Liquid -> Solid Solid -> Gas

22 Chemical Changes Process that involves one or more substances changing into a new substance Commonly referred to as a chemical reaction New substances have different compositions and properties from original substances

23 Chemical Changes Signs of a Chemical Change change in color or odor
formation of a gas formation of a precipitate (solid) change in light or heat

24 Change of Energy All physical & chemical changes involve a change of energy. Endothermic – energy absorbed a positive number (+) means endothermic feel cold to the touch Exothermic – energy released a negative number (-) means exothermic feel warm or hot to the touch Do demo bleach and sodium sulfite and ammonium nitrate and water.

25 Some Chemical Changes Combustion Corrosion Electrolysis Fermentation
Metabolism Photosynthesis Bubble formation Temperature change Smell Rust

26 Tip for Distinguishing
Is the change permanent? Can I get the original substance back after the change?” If so, it is a physical change. If not, it is a chemical change.

27 Physical vs. Chemical Changes
Examples: rusting iron dissolving in water burning a log melting ice grinding spices chemical physical

28 What Type of Change?

29 What Type of Change?

30 Law of Conservation of Mass
Although chemical changes occur, mass is neither created nor destroyed in a chemical reaction Mass of reactants equals mass of products massreactants = massproducts A + B  C

31 Conservation of Mass GIVEN: WORK: 10.00 g = 9.86 g + moxygen
In an experiment, g of red mercury (II) oxide powder is placed in an open flask and heated until it is converted to liquid mercury and oxygen gas. The liquid mercury has a mass of 9.26 g. What is the mass of the oxygen formed in the reaction? GIVEN: Mercury (II) oxide  mercury + oxygen Mmercury(II) oxide = g Mmercury = 9.86 g Moxygen = ? WORK: 10.00 g = 9.86 g + moxygen Moxygen = (10.00 g – 9.86 g) Moxygen = 0.74 g Mercury (II) oxide  mercury + oxygen Mmercury(II) oxide = g Mmercury = 9.26 Moxygen = ? massreactants = massproducts

32 Can it be physically separated?
Matter Flowchart MATTER yes no Can it be physically separated? MIXTURE PURE SUBSTANCE Is the composition uniform? no yes Can it be chemically decomposed? no yes Homogeneous Mixture (solution) Heterogeneous Mixture Compound Element

33 Matter Flowchart Examples: graphite pepper sugar (sucrose) paint soda
element hetero. mixture compound solution

34 Pure Substances Element composed of identical atoms
EX: copper wire, aluminum foil

35 Pure Substances Compound- ex. table salt (NaCl) Molecule
composed of 2 or more elements in a fixed ratio properties differ from those of individual elements Molecule smallest particle of a compound

36 Mixtures Variable combination of 2 or more pure substances that is physically combined. There is no particular ratio and each part of the mixture keeps its own properties. Ex. Perfume, potting soil, salad dressings, and tea. Heterogeneous Homogeneous

37 Mixtures Solution Homogeneous mixture very small particles
substances are in the same amount in all parts of the mixture particles don’t settle ex. rubbing alcohol, perfume

38 Mixtures Heterogeneous medium-sized to large-sized particles
substances in the mixture are not evenly mixed particles may or may not settle ex. milk, fresh-squeezed lemonade, salad dressing, potting soil

39 Heterogeneous Mixtures
Colloid: a heterogeneous mixture with larger particles that never settle; scatter light in the Tyndall effect. Ex. Milk Suspension: a heterogeneous mixture containing a liquid in which visible particles settle

40 Mixtures Examples: Answers: tea Solution muddy water Heterogeneous fog
saltwater Italian salad dressing Answers: Solution Heterogeneous

41 Separating Mixtures Substances in a mixture are physically combined, so processes based on differences in physical properties are used to separate component Numerous techniques have been developed to separate mixtures to study components Filtration Distillation Crystallization Chromatography

42 Filtration Used to separate heterogeneous mixtures composed of solids and liquids Uses a porous barrier to separate the solid from the liquid Liquid passes through leaving the solid in the filter paper

43 Distillation Used to separate homogeneous mixtures
Based on differences in boiling points of substances involved

44 Crystallization Separation technique resulting in the formation of pure solid particles from a solution containing the dissolved substance As one substance evaporates, the dissolved substance comes out of solution and collects as crystals Produces highly pure solids Ex. Rocky candy

45 Chromatography Separates components of a mixture based on ability of each component to be drawn across the surface of another material Mixture is usually liquid and is usually drawn across chromatography paper Separation occurs because various components travel at different rates Components with strongest attraction for paper travel the slowest


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