1. Matter comes in phases, they are: and! 3. Energy is associated with the phases as well: Gases have the energy, solids the

Transcription

1 Phases Chemistry Notes 1. Matter comes in phases, they are: and! 2. There are six phase changes that you need to know always: Between solid and liquid: & Between liquid and gas: & Between solid and gas: & 3. Energy is associated with the phases as well: Gases have the energy, solids the 4. Water is our most common substance, and therefore we need to always be aware of the temperatures that the phase changes occur at (at normal pressures). 5. On that chart, list the important temperatures for water, all phases, and indicate all the phase changes. 6. Why is water weird?

2 7. What 2 things impact the boiling point of a substance? & 8. Air pressure is measured with these unusual units A. (atm). B. (mm Hg). C. (kpa). D. (psi). LOOK now at table A on the reference tables. Normal temperature is both &, 10. Normal Pressure is 11. Normal air pressure is sometimes still measured in. (think bike tires) 12. Normal pressure is psi. 14. My water is about a 0.75 pounds, so the pressure that this water would create if I turned it upside down would be slight about psi 15. Let s convert higher than normal air pressure of 145 kpa into atmospheres 16. The pressure in a balloon is 905 mm Hg. What s that in kpa (kilopascals)? 17. As you climb up Mt. Everest (which is totally unsafe and also dangerous) the air pressure drops from normal to about 31.0 kpa. What is that in atmospheres?

3 18. The air pressure in a scuba tank is in the range of 224 atm. Convert that into kilo-pascals. 19. The of gases states that gases A. B. C. D. E. F. G.

4 20. Gas pressure 21. invented the Torricelli Tube, AKA: 22. Today it s a higher pressure day (cold air is denser than warm), so the pressure outside is about 825 mm Hg. Convert that to atmospheres and then to kilopascals. 23. In Boulder, Colorado, where my mean sister in law Donna lives, the air pressure is notably lower than Vestal. That s because she s so high in the mountains, there is less air pressing on them than at lower altitudes like here. Air pressure in Boulder the other day was just 644 mm Hg. You d be light headed probably. Convert that to atm and to kpa 24. Convert 40.0 kpa into mm Hg and then into atm.

5 25. Convert 2.55 atm into kilopascals and then into mm Hg 26. Convert these 4 now A. 120⁰C into Kelvin B. 327 Kelvin to centigrade C atm to mm Hg D atm to kpa 27. Liquids are 28. When liquids get enough energy they reach the. At the boiling point molecules of a liquid have enough energy to go into the gas phase. This is called. 29. Evaporation means 30. Evaporation happens to liquid at temperature. 32. The hotter liquids are, evaporation occurs, since more particles get enough energy to leap to a gas. 33. Evaporation is If this liquid is boiling: 36. Where does Donna the Witch live? Why is that good for us here?

6 37 Draw the diagrams, fill in the boxes Vestal Warm kpa 70 C Vestal Hot kpa 100 C Boulder Hot 85.0 kpa ~97 C Water boil. It can t over come the internal attraction and downward. happens Water boil. It can overcome the internal attraction and downward. happens Water boils at a! There is less air pressure holding it down in the pot! happens 38. Liquids (even water) boil when enough energy to overcome the pushing down upon the surface. 39. Boiling point is NOT JUST temperature driven, it s controlled by the and the together. 40. High pressures will the energy required to boil any liquid. Lower pressures will the energy needed to boil a liquid. 41. The internal attraction of the particles is for each particular liquid. This internal attraction is measured as..

7 42. In a closed system. 43. If the system is heated If it s cooled 44. This space above the water contains air 45. Draw this graph 46. Draw in NBP Normal Boiling Point 47. What does that CURVED LINE indicate? Label it on the graph too. 48. Indicate where the liquids are. 49. Indicate where the gases are. 50. Table H is the Vapor Pressure is...

8 Phases Class #4 (finish that diagram quickly) 51. In a closed system: 52. If the close system is heated: 53. The extra pressure: 54. Table H is the vapor pressure: 55. On table H, looking only at water: At each point, what is the PHASE of water? kpa + 40⁰C 75 kpa + 95⁰C 150 kpa + 110⁰C 20 kpa + 65⁰C 56. How much extra pressure is added to a sealed flask containing water at 50⁰C? 56A. (what s the vapor pressure of water at 50⁰C?)

9 Draw both the HEATING curve for CADMIUM, and the COOLING curve for COBALT on this graph. Write their boiling point and freezing point on this page so you can see them BEFORE you start to draw the lines K 2800 K 2100 K 1400 K 700 K Zero K Energy Added (or removed) at a constant rate 59. Why are the flat lines different lengths on every heating curve? Heating Curve for H2O 60. BC represents 61. DE represents

10 This is the PHASE DIAGRAM for WATER. Recopy it. Label it. Label Normal FP and Normal BP, CP, and TP Imagine you have two beakers of liquid, one has 500. ml ethanol alcohol and the other has 500. ml of propanone. They are sitting on the desk in front of you. Put a cork into each top. AIR PRESSURE is kpa. Warm up the room to 25⁰C 65. What is pressure inside each flask? Ethanol Propanone

11 Ethanol Propanone 66. Both start at kpa, but now we heat up the room that these flasks are in to 65⁰C. What is the pressure inside of each flask now? Label the diagram Properties of SOLIDS, LIQUIDS, and GASES 67. Solids Liquids Gases Parcle Aracon Parcle Arrangement Shape/Volume in container Relave Density Heat Expansion? Relave Kinec Energy

12 68. Today s pressure is exactly 1.14 atm. Convert that to mm Hg, and kpa right now 69. At any temperature, say 65 C, ethanonic acid has the lowest vapor pressure, propanone the highest. WHY??? 70. Take out Table H, put these 2 notes right into your reference table NOW. 71. Heating curve practice.. Label points A to F left to right. Show what happens to Temperature from points BC and DE Then explain Potential Energy from BC and DE 72. If kinetic energy is changing, What does the potential energy do from C to D?

13 73. Kinetic Energy & Temperature are. The greater the KE, the Lower temp = 74. Temp + Kinetic energy are like Michael Jackson s hand & his glove. What ever one does, so does the other. 75. The other energy,, is used when there is no change in the kinetic energy. It s for those phase change times. 76. If kinetic energy (temp) is changing,. 77. In a phase change kinetic energy is steady (so is temp), then the PE or in a heating curve, Or if the kinetic energy is steady (so is temp), then the PE in a cooling curve. Show what Potential Energy is doing on every segment here (label A to F, left to right first)