Classification of Matter

1. Classification of Matter Unit 2

2. Which of the following are examples of matter? • Rock • Water • Carbon dioxide • 1 & 2 only • All of the above

3. What criteria must be met in order to be matter? Is Gas Matter? What about Helium ?

5. Investigation • Without bumping the table, add 1 drop of food coloring to your hot water and 1 drop to your “cold” water. Observe carefully for 1 minute. • Write down your observations, then look again at your beakers and make any further observations • What do you think is different about the hot and cold water that caused this difference?

6. How many phases of matter exist? • One • Two • Three • Four

7. PHASES OF MATTER Matter exists in four States (or Phases): • Solid • Liquid • Gas • Plasma

9. Solids…. • are packed tightly together in an organized pattern • have a definite shape and volume • Particles do not move much, but vibrate in place

10. Liquids…. • Particles move freely over one another in an unorganized pattern • Do NOT have definite shape - take shape of container • DO have a definite volume • Particles stay in close contact with each other, but usually less dense than solid

11. What do you think will happen when the solid is dropped in to the liquid? Solid Methanol • It will Float • It will Sink • It will ‘hang’ midway Liquid Methanol

12. We would expect the solid to sink because the particles are more closely packed in a solid than liquid Solid Methanol Can you think of an exception to this trend?

13. Water: Exception to the Rule

14. Liquids…. • Do NOT have definite shape - take shape of container • DO have a definite volume (can not be compressed) • Particles stay in close contact with each other, but usually less dense than solid • Particles freely move over one another in an unorganized pattern

15. Gases…. • Gas does have mass • Particles are very spread out and move a lot • Do NOT have definite shape - take shape of container • Do NOT have a definite volume - fill volume of container. Can be compressed (volume can be made smaller) • Collisions of particles with wall causes Pressure

16. Animation of Phase Changes

17. Factors affecting Volume of Gas • Change in temperature will change volume. • An increase in temperature will cause an _______ in volume of a gas • Charles Law V1/T1 = V2/T2 • Change in pressure will change volume • An increase in the outside pressure will cause a(n) _________ in the volume of a gas. • Boyles’ Law P1V1 = P2V2 increase Is this a direct or inverse relationship? decrease Is this a direct or inverse relationship?

18. What are two ways to increase the pressure in a basketball? • Increase the Amount of Gas • more gas particles means more collisions • Increase the Temperature • Particles move faster, means more collisions • Faster moving particles mean collisions have more force

19. Pressure vs Temperature • At a fixed volume, changing temperature will affect the pressure

20. Pressure vs Temperature • At a fixed volume, changing temperature will affect the pressure • An increase in temperature will cause a(n) _________ in pressure • P1/T1=P2/T2 • Finish this sentence… “Increasing the temperature of a gas at fixed volume will cause an increase in pressure because….” increase Is this a direct or inverse relationship?

21. Back to our colored water investigation • Let’s share our observations • Write a new explanation to explain why the coloring behaved differently • What was different about your original explanation and your new explanation?

22. Units of Temperature & Air Pressure • When using gas law formulas, all Temperatures must be in Kelvin • Kelvin = °C + 273 • Example Room Temp of 25°C + 273 = 298K • Units of Standard Air Pressure • 1.00 Atmosphere (atm) • 760 millimeters of mercury (mm Hg) • 101,325 Pascals (Pa) • 29.92 inches of mercury (in Hg) • 14.70 psi

23. If the air pressure today is 29.32in Hg what is the pressure in mm Hg? • 22,280 mmHg • 25.92 mmHg • 744.8 mmHg • 755.3 mmHg • 775.6 mmHg • 1.15 mmHg

24. Which of the following is not true of gases? • They have mass • They exert pressure • They have a definite volume • They have large distance between particles.

25. Which of the following will not cause an increase in pressure? • Adding more gas • Lowering the temperature • Reducing the volume the gas occupies

26. A gas initially at 2.0 atm is in an adjustable volume container of 10. L in volume. If the outside pressure is increased to 4.0 atm, what is the new volume? • 40.L • 20.L • 10.L • 5.0L

27. Assuming pressure is held constant, to what volume will a balloon initially at 1.0 L change if its temperature is decreased from 300 K to 75 K? • 1.0 L • 2.0 L • 4.0 L • 0.25 L • 0.50 L

28. Almost all substances can exist as solids, liquids, or gases • The phase will depend on the temperature, pressure, and attractive forces of particles • As substance gains kinetic energy (Temperature), it will change phases • Solid --> Liquid --> Gas --> Plasma

29. Phase Changes MELTING FREEZING Solid Liquid Liquid Gas Solid Gas EVAPORATION CONDENSATION SUBLIMATION DEPOSITION

30. SUBLIMATION: A phase change that skips the liquid state.

31. Learning Check: True or False

32. 15 All substances can exist in all 3 states • True • False

33. 15 The faster gas particles are moving, the more pressure they will exert. • True • False

34. 15 Water always boils at 100 degrees C • True • False

35. 15 Liquids and solids both have a definite volume • True • False

36. 15 All three phases expand or contract with changes in temperature • True • False

37. Warm-Up: Gas Law Info: V1P1=V2P2 V1/T1 = V2/T2 P1/T1 = P2/T2 A basketball is inflated to a pressure of 465.4 mm Hg at a temperature of 298K. If the basketball can withstand a pressure 195.3 kPa before it bursts, what temperature would we need to heat it up to before it blows up? (Assume the volume of the basketball does not change after it was inflated). Put your answer inC. Standard Air Pressures: 760.0 mm Hg 1.000 atm 101,325 Pa Temperature TK = TC + 273 Answer on next slide

38. Warm-Up: Gas Law Info: V1P1=V2P2 V1/T1 = V2/T2 P1/T1 = P2/T2 Answer: 938 K or 665  C Standard Air Pressures: 760.0 mm Hg 1.000 atm 101,325 Pa Temperature TK = TC + 273

39. Time to Investigate Properties of Gases • Gas Stations Lab • Boyles’ Law Graphing POGIL

40. Element, Compounds, Mix • Warm-Up: • Read Page 77 in text and complete Sections 1,2, & 4 on page 3 of Unit 2 Packet.

41. Elements Silver Oxygen Carbon • Homogeneous • Made of only 1 type of atom • Simplest form of matter • Can’t be broken down • Pure Substance

42. Compounds Water Salt Sugar • H2O • NaCl • C12H22O11 • Made of only 1 type of Molecule • Pure Substance • Can be separated chemically, not physically • Each substance gains new identity (ex NaCl) • Has a definite ratio • Homogeneous • 2 or more types of atoms Chemically Bonded

43. Mixtures Chex Mix Chili Kool Aid • Can appear heterogeneous or homogeneous (solutions are homogeneous mixtures) • 2 or more types of atoms/molec. Physically Blended -- see pic of all three. • Impure substance • Can be separated physically • Ratio of components not exact • Each Substance maintains its identity No Magic

44. Your Turn: Which of the following pictures represent: • Pure Elements • Elements made of single atoms • Elements made of molecules • Mixtures • Pure Compounds • Mixture of 2 compounds • Mixture of 2 elements

45. Types of Homogeneous Mixtures:Solutions • A True Homogeneous mixture • All particles are broken down into individual molecules or ions • A beam will light will pass straight through, with no dispersion. • Examples: Saltwater, Kool-Aid

46. Types of Homogeneous Mixtures:Colloidal Suspensions (Colloid) • Appear Homogeneous • Breaks down into small “clumps” of molecules, but not into individual molecules • Examples: mayonnaise, Jell-O, fog, butter and whipped cream • Tyndall Effect – will scatter a beam of light passed through it. (Ex. Light reflecting off dust in the air)

47. Distinguishing Colloids from Solutions: The Tyndall Effect

48. Types of Colloids Fog, mist Smoke Whipped Cream Mayonnaise Latex paint Styrofoam Jelly, butter Alloys (steel)

49. Classification of Matter

50. Example: putting iron and sulfur together.