Properties of Matter: States, Substances, and Mixtures

1. Chapter 1“Matter and Change”

2. Section 1.3Properties of Matter • OBJECTIVES: • Define physical property, and list several common physical properties of substances. • Distinguish between matter and substances

3. Section 1.4Properties of Matter • OBJECTIVES: • Differentiate among three states of matter.

4. Section 1.5Properties of Matter • OBJECTIVES: • Describe a physical change.

5. Matter • Matter is anything that: a) has mass, and b) takes up space • Mass = a measure of the amount of “stuff” (or material) the object contains (don’t confuse this with weight, a measure of gravity) • Volume = a measure of the space occupied by the object

6. Substances • Matter that has a uniform and definite composition. • Either a pure element or a compund • Salt is a substance • Every sample of NaCl tastes the same, melts at the same temp., and is 39.3% Na and 60.7% Cl by mass. • What about a cup of coffee? • No, each cup can have different strengths or different amounts of sugar.

7. Properties are… • Words that describe matter (adjectives) • Physical Properties- a property that can be observed and measured without changing the material’s composition. • Examples- color, hardness, m.p., b.p. • Chemical Properties- a property that can only be observed by changing the composition of the material. • Examples- ability to burn, decompose, ferment, react with, etc.

8. States of matter • Solid- matter that can not flow (definite shape) and has definite volume. • Liquid- definite volume but takes the shape of its container (flows). • Gas- a substance without definite volume or shape and can flow. • Vapor- a substance that is currently a gas, but normally is a liquid or solid at room temperature. (Which is correct: “water gas”, or “water vapor”?)

9. States of Matter Result of aTemperatureIncrease? Definite Volume? Definite Shape? Will it Compress? Small Expans. Solid YES YES NO Small Expans. Liquid NO NO YES Large Expans. Gas NO NO YES

10. 4th state:Plasma - formed at high temperatures; ionized phase of matter as found in the sun

11. Three Main Phases

12. Condense Freeze Evaporate Melt Gas Liquid Solid

13. Copper Phases - Solid

14. Copper Phases - Liquid

15. Copper Phases – Vapor (gas)

16. Physical vs. Chemical Change • Physical change will change the visible appearance, without changing the composition of the material. • Boil, melt, cut, bend, split, crack • Is boiled water still water? • Can be reversible, or irreversible • Chemical change - a change where a new form of matter is formed. • Rust, burn, decompose, ferment

17. Recap • What makes matter a substance? • Has a uniform and definite composition • What is the difference between a solid, liquid and gas? • Solid has a definite shape • Liquid takes the shape of it’s container • Gas will expand to volume it occupies • What are some examples of physical changes? • Melting, Bending, Cutting apart, freezing, dissolving

18. Section 1.6Mixtures • OBJECTIVES: • Categorize a sample of matter as a substance or a mixture.

19. Section 1.6Mixtures • OBJECTIVES: • Distinguish between homogeneous and heterogeneous samples of matter.

20. Section 1.6Mixtures • OBJECTIVES: • Describe two ways that components of mixtures can be separated.

21. Mixtures are a physical blend of at least two substances; have variable composition. They can be either: • Heterogeneous – the mixture is not uniform in composition • Chocolate chip cookie, gravel, soil. • Homogeneous - same composition throughout; called “solutions” • Kool-aid, air, salt water • Every part keeps it’s own properties.

22. Solutions are homogeneous mixtures • Mixed molecule by molecule, thus too small to see the different parts • Can occur between any state of matter: gas in gas; liquid in gas; gas in liquid; solid in liquid; solid in solid (alloys), etc. • Thus, based on the distribution of their components, mixtures are called homogeneous or heterogeneous.

23. Mixtures two or more substances mixed together …have varying composition …have varying properties The substances are NOT chemically bonded, and they… retain their individual properties. Tea, orange juice, oceans, and air are mixtures.

24. salt water Kool Aid bronze (Cu + Sn) pewter (Pb + Sn) brass (Cu + Zn) Two Types of Mixtures homogeneous: (or solution) particles are microscopic; sample has same composition and properties throughout; evenly mixed e.g., alloy: a homogeneous mixture of metals e.g.,

25. tossed salad raisin bran paint snowy-bulb gifts Two Types of Mixtures (cont.) heterogeneous: different composition and properties in the same sample; unevenly mixed e.g., suspension: settles over time e.g.,

26. Contrast… 24K GOLD 14K GOLD 24/24 atoms are gold 14/24 atoms are gold mixture of gold & copper pure gold element homogeneous mixture Au Au + Cu

27. Phase? • The term “phase” is used to describe any part of a sample with uniform composition of properties. • A homogeneous mixture consists of a single phase • A heterogeneous mixture consists of two or more phases. • Note Figure 1.8, page 12

28. Separating Mixtures • Some can be separated easily by physical means: rocks and marbles, iron filings and sulfur (use magnet) • Differences in physical properties can be used to separate mixtures. • Filtration - separates a solid from the liquid in a heterogeneous mixture (by size)

29. Components of dyes such as ink may be separated bypaper chromatography. Separation of a Mixture

30. Separation of a Mixture Distillation:takes advantage of different boiling points. NaCl boils at 1415 oC

31. decant: to pour off the liquid blood after high- speed centrifuging Separating Mixtures (cont.) 5. density: “sink vs. float” perhaps use a centrifuge

32. Section 1.7Elements and Compounds • OBJECTIVES: • Explain the differences between an element and a compound.

33. Section 1.7Elements and Compounds • OBJECTIVES: • Distinguish between a substance and a mixture.

34. Section 1.8Elements and Compounds • OBJECTIVES: • Identify the chemical symbols of elements, and name elements given their symbols.

35. Substances are either: a) elements, or b) compounds

36. Substances: element or compound • Elements- simplest kind of matter • cannot be broken down any simpler and still have properties of that element! • all one kind of atom. • Compounds are substances that can be broken down only by chemical methods • when broken down, the pieces have completely different properties than the original compound. • made of two or more atoms, chemically combined (not just a physical blend!)

37. Classifying Matter (Pure) Substances …have a fixed composition …have fixed properties ELEMENTS COMPOUNDS e.g., Fe, N2, S8, U e.g., H2O, NaCl, HNO3 sodium chloride (NaCl) sulfur (S8) Pure substances have a chemical formula.

38. Made of one kind of substance Made of more than one kind of substance Made by a chemical change Made by a physical change Definite composition Variable composition Compound vs. Mixture Compound Mixture

39. Element Compound Mixture Which is it?

40. Elements vs. Compounds • Compounds can be broken down into simpler substances by chemical means, but elements cannot. • A “chemical change” is a change that produces matter with a different composition than the original matter.

41. Chemical Change A change in which one or more substances are converted into different substances. Heat and light are often evidence of a chemical change.

42. Properties of Compounds • Quite different properties than their component elements. • Due to a CHEMICAL CHANGE, the resulting compound has new and different properties: • Table sugar – carbon, hydrogen, oxygen • Sodium chloride – sodium, chlorine • Water – hydrogen, oxygen

43. PURE SUBSTANCE MIXTURE ELEMENT COMPOUND HETEROGENEOUS HOMOGENEOUS Chart for Classifying Matter MATTER

44. Symbols & Formulas • Currently, there are 117 elements • Elements have a 1 or two letter symbol, and compounds have a formula. • An element’s first letter always capitalized; if there is a second letter, it is written lowercase: B, Ba, C, Ca, H, He • Start learning the elements names and symbols listed in Table A.1 on page 782 • Some names come from Latin or other languages; note Table 1.5, page 17

45. Recap • What is a mixture? • A physical blend of two or more substances • What is the difference between homogeneous and heterogeneous mixtures? • Homogeneous – uniform composition • Heterogeneous – mixed/not uniform composition • What is the difference between an element and a compound? • Elements: Made of one type of atom, can not be separated into simpler substances • Compound: Made of different elements. Can be separated by chemical means. • What are the English names of these elements? Au, Cu, Hg, Pb, Sn, Fe, K, Na Gold, Copper, Mercury, Lead, Tin, Iron, Potassium, Sodium

46. Lab Write Ups • Purpose • Hypothesis • Procedure & Materials • Observations/Data (organized) • Analysis • Make conclusions • Communicate

47. Lab Write Ups • Purpose: Ask a question and use to write the purpose. “Can I tell if ink is a mixture using chromatography to separate it’s components?” Change to: Purpose: To use chromatography to determine if an ink is an mixture. • Hypothesis: An ink is not a mixture and will not separate into different components when using chromatography.

48. Lab Write Ups • Procedures: List the exact steps you will use to complete your experiment. Use diagrams/photo’s when appropriate (a picture is worth a thousand words). • Materials: List the materials you will use. • Observe and collect data: Organize it table formate. • Analyze the data: Use graphs and statistics to help with analysis. • Make conclusions and communicate. Write a paragraph or two discussing your analysis and what conclusions you can make from your observations and data. • (Communication comes in the form of a lab report with all of the above steps written down or a presentation with each step discussed and presented.)

49. Lab Write Ups • What did you learn? • Is Ink a mixture or a substance? • Why? • How many different components did you observe?

50. Section 1.9Chemical Reactions • OBJECTIVES: • Describe what happens during a chemical change.