Chapter Two

1. Chapter Two • Temperature • % Error • S-L-G • Physical vs Chemical Properties • Chemical and Physical Changes • Conservation of Mass/Law Def Proportions • Matter Classification Chart

2. Classification of Matter

3. Physical Properties are characteristics that can be observed without changing the identity of a substance. • Color • Size • Shape • Height • Mass • Odor • Texture • Luster • Solubility • State of Matter • Hardness • Conductibility • Volume • Melting Point • Boiling Point • Malleability • Polarity • Magnetism

4. Physical Properties of Matter Extensive Intensive Properties that do not depend on the amount of the matter present. • Properties that do depend on the amount of matter present.

5. Density = ? • Density is the ratio of two______ properties 1) Extensive 2) Intensive • Density is which type of property: 1) Extensive 2) Intensive

6. Homework: • It is sometimes said that many ostensibly physical properties are supervenient to an underlying reality. What does that mean?

7. Chemical Properties: behavior of a substance when it undergoes a chemical change or reaction • Reactivity • Toxicity • coordination number • Flammability • Enthalpy of formation • Heat of combustion • oxidation states • chemical stability • types of chemical bonds that will form

8. Chemical Properties • Flammability – the ability of an object to to burn • Paper and Wood will burn, they are flammable. • Gold will not burn, it melts. It is nonflammable. • Reactivity – capacity of a substance to combine with another substance • Sodium is highly reactive with water. • Metals have a tendency to react with Acids • Iron reacts with Oxygen in the air to form rust.

9. Flammable vsInflammable vsNonflammable

10. Chemical vs Physical Chemistry is the study of matter, its properties and the changes that it undergoes.

11. Physical Change • The internal composition of something does not change. It remains the same chemical. • Changes of state are PHYSICAL CHANGES. • Examples: Ripping paper, crushing a can, cutting hair, breaking chalk, molding Play-Doh cracking an egg.

13. Physical Changes CHANGES OF STATE Ice Melting!!!! Changes of state are a physical change. Liquid water (H20) that turns into ice is still (H2O) Melting, Freezing, Boiling and Evaporation are physical changes. Gallium melting in hand!

14. Two Types of Physical Changes • Reversible and Irreversible • Irreversible Physical Change: something that cannot be undone. For example, you cannot uncrack an egg or uncut hair. • Reversible physical change: a change that can be reversed. These are phase changes. Ice that melts can be refrozen.

16. Burn Burn Burn

17. Chemical Changes • One or more substances changes into something new. The internal properties of a substance change. • Example: Burning Paper (combustion in general), digestion of food, rusting, fireworks exploding, cooking an egg, any chemical reaction.

18. Hoffman Apparatus: Electrolysis • Electrocuting water (H2O) causes its bonds to break and it separates into H2 and O2 • This is a CHEMICAL CHANGE, something new forms. • H2O + Electricity  H2 + O2

20. 4 Clues a Chemical Change might have taken Place Four Clues 5ml Silver Nitrate in two test tubes. Add Sodium Chloride solution to one (CC) and Potassium Chromate to another (FP). Or Potassium iodie and lead nitrate (CC). 5mL of Sulfuric acid in two test tubes, one add mossy zinc the other marble (Calcium Carbonate) • Transfer of Energy • Color Change • Formation of a Precipitate • Production of Gas

21. CHEMICAL OR PHYSICAL CHANGE? Baking Soda and Vinegar Chemical or Physical Cooking an Egg Ripping Paper Lighting a Match A C₃H₈O molecule evaporating Ice Melting Mixing Baking soda and vinegar Getting a suntan

22. Dissolving Salt in Water Chemical Change Physical Change

23. Disassociation:

25. Its 295 degrees in here • Is that an accurate statement?

26. Fahrenheit • Based upon the human body. ~100°F is the temperature of the human body • 0°F is the coldest George Fahrenheit could chill brine to. • Water: • Freezing point is 32°F • Boiling point is 212°F

27. Celsius • Built around water. • 0°C is the freezing point • 100°C is the boiling point • Most of the world uses it.

28. Kelvin • Thermodynamic Temperature Scale • 0°K is the coldest possible temperature where molecular motion stops. • Defined in terms of the kinetic theory of matter.

30. What are the conversions?

31. Temperature Conversions

32. Fill in the Temperatures

33. Y= mx + b • Equation of a line • m = slope • b = y intercept

35. Temperature Conversions: Slope-Intercept • Y = mx + b • C = x • F = 1.8C +32 • K = C+273.15

36. Calibrating a Thermometer Lab

37. Percent Error A percent error tells you how far off an experimental value is from the currently accepted or theoretical value.

38. Percent Error Samples • The accepted value for the density of gold is 19.3g/cm3. A student working in the lab measured it to be 18.7g/cm3. What was the student’s percent error? • A student measures the acceleration due to gravity on earth to be 9.86m/s2 whereas the currently accepted value is 9.8m/s2. How far off was this student?

39. Percent Error Problems Clyde Clumsy was directed to determine the mass of a 500g piece of metal. After diligently goofing off for ten minutes, he quickly weighed the object and reported 458g. 2) Willomina Witty was assigned to determine the density of a sample of nickel metal. When she finished, she reported the density of nickel as 5.59 g/ml. However, her textbook reported the density of nickel to be 6.44 g/ml. 3) An experiment to determine the volume of a "mole" of a gas was assigned to Barry Bungleditup. He didn't read the experiment carefully and concluded the volume was 18.7 liters when he should have obtained 22.4 liters. 4) A student should have received a 93 for a grade but Mr. Sapone accidentally (Scouts honor!) put in an 83 instead. Calculate Mr. Sapone’s error.

40. Create a Matter Graphic Organizer • Is either a pure substance or a mixture. • Pure Substances Include Elements and Compounds. • Mixtures can be broken into two types: heterogeneous and homogeneous.

41. MATTER Mixtures Pure Substances Heterogeneous Homogeneous Elements Compounds Examples: Examples: Examples: Examples:

42. Pure Substances • A pure substance is a sample of matter, either a single element or a single compound, that has definite chemical and physical properties.

43. Mixtures • A mixture is a combination of two or more substances that are not chemically combined.

44. Two Types of Mixtures • Heterogeneous Mixture - the components aren’t mixed uniformly and are not evenly distributed----easily separated. • Salad, Pizza, Lucky Charms, Granite, beach sand • Homogeneous Mixture - the components are evenly distributed, the mixture is the same throughout, and it is not easily separated. • Stainless steel, blood, corn olive

45. Separating Mixtures Ethanol (C2H6O) Freezes at -114°C • In the real world most things we eat, drink and encounter are mixtures. • The stuff of our lives is a physical blend of pure substances (mixture). • Separating mixtures is an important part of chemistry. • How would you separate a mixture of alcohol and water?

46. Helium • Product of Uranium Ore • Small quantities in natural gas. • Losing it to space. • Cryogenically separated from the gas due to physical properties.

47. Distillation: The act of separating liquid solutions through vaporization and condensation.

48. Filtration: usually used to separate solids from fluids.

49. Bear Grylls: filtration and distillation • http://adventure.howstuffworks.com/27877-man-vs-wild-purifying-water-in-the-wild-video.htm

50. Paper Chromatography • Separation by inner molecular attractions. Some mixtures have components that “stick” to materials in different ways. These attractions take place at the molecular level.