Unit 8: Kinetic Theory Homework Packet (90 points)

Transcription

1 Name: Key Period: By the end of Unit 8, you should be able to: Kinetic Theory Chapter Define kinetic theory of gases including collisions 5. Define pressure, including atmospheric pressure, vapor pressure, pressure differentials, and how a barometer works 6. Describe boiling points, including normal boiling points, using vapor pressure graphs, explaining the difference between boiling and evaporation, and how intermolecular forces and molecular weight determine evaporation rates 7. Define and use data based on the triple point phase diagram 8. Define and know the variables of the Gas Laws, including Boyle s Law, Charles Law, Gay-Lussac s Law, and the combined gas law 9. State Avogadro s Principle 10. Use the ideal gas law to solve problems and know the variables of the ideal gas law 11. State and use Dalton s Law of Partial Pressures 12. State and use Graham s Law of effusion and define diffusion Kinetic Theory: State the properties of the kinetic theory of gases and explain what is meant by each. (pg. 420) 1. Property: Gas particles neither repel nor attract each other. Explanation: Gases can be compressed or expanded. 2. Property: Explanation: 3. Property:_Collisions between gas particles are elastic._ Explanation: There is no net loss of kinetic energy when gases particles collide. goldchemistry.wordpress.com Page 1

2 Temperature and Pressure: Answer the following questions. (pg ) 4. Define pressure. 5. Using the reading from the barometer on the right, what is the pressure in the following units: a. _ kpa b. atm c. _101,033 Pa d. torr 6. Explain the difference between temperature and heat. 7. Do all particles at a given temperature have to move at the same speed? No, some particles are moving faster and some slower. The temperature is the average kinetic energy. 8. Convert the following temperatures into the desired units: a. 25 C is F b. 25 C is K c. 324 K is C d. 32 F is K 9. What makes the Kelvin scale ideal for working with gases? The Kelvin scale accurately shows the amount of kinetic energy by stating that 0 K has no motion. As motion increases, so will the Kelvin scale. Also, there are no negative values to worry about. goldchemistry.wordpress.com Page 2

3 10. What are the values of standard temperature and pressure (STP) in atm and C. Boiling Points: Answer the following questions. (pg ) 11. Define a normal boiling point. The boiling point at atmospheric pressure. 12. Define vapor pressure. Use the diagram at the right for # What is the boiling point of water when the vapor pressure is 200 torr? 68 C 14. Which substance has its boiling point with a vapor pressure at 450 torr at 20 C? 15. Based on the graph, what temperature must it be for ethyl alcohol to boil if the vapor pressure is 200 torr? 48 C 16. Based on the graph, what temperature must it be for water to boil if the vapor pressure is 400 torr? 17. Based on the graph, what temperature must it be for diethyl ether to boil if the vapor pressure is 400 torr? 18 C 18. How would intermolecular forces affect evaporation rates? goldchemistry.wordpress.com Page 3

4 19. How would molecular weight affect evaporation rates? Triple Points: Use the diagram to the right for questions # (pg ) 20. Using the diagram to the right, what phase of matter is indicated in the section marked: a. b. c. 21. What is denoted at point D? Triple Point 22. What is denoted at point E? The triple point diagram above shows data for CO 2. Use the diagram for problems # What is the approximate temperature and pressure of the triple point for carbon dioxide? 7 bar and 215 K 24. What is the approximate temperature and pressure of the critical point for carbon dioxide? 25. At STP (1 bar), what is the state of matter of carbon dioxide? gas goldchemistry.wordpress.com Page 4

5 26. At 24 C and 100 bar, what is the state of matter of carbon dioxide? 27. What pressure would be required to make solid carbon dioxide (dry ice) at room temperature (72 F)? 7000 bar Boyle s Law: Answer the following questions. Show all work and units. (pg ) 28. What is the equation for Boyle s Law? 29. Is this an inverse or direct relationship? inverse 30. If the pressure doubles, what happens to the volume? 31. If the volume is tripled, what happens to the pressure? Reduced to 1/3 of the original amount 32. A sample of gas has a volume of 23.4 ml and a pressure of 1.35 atm. What will the volume be if the pressure is increased to 4.78 atm if the temperature is held constant? 33. A sample of O 2 gas has a volume of 150 ml when its pressure is atm. What will the volume of gas be at a pressure of atm if the temperature remains constant? 144 ml 34. A gas has a pressure of 1.26 atm and occupies a volume of 7.4 L. If the gas is compressed to 2.93 L, what will its pressure be if the temperature remains constant? goldchemistry.wordpress.com Page 5

6 Charles Law: Answer the following questions. Show all work and units. (pg ) 35. What is the equation for Charles Law? V 1/T 1=V 2/T Is this an inverse or direct relationship? 37. If the temperature doubles, what happens to the volume? Doubles 38. If the volume is tripled, what happens to the temperature? 39. A gas at 300. K fills a container that has a volume of 425 ml. What will the temperature be in K if the volume expands to 4250 ml? Pressure is held constant K 40. A sample of neon gas occupies a volume of 752 ml at 25ºC. What volume will the gas occupy at 50ºC if the pressure remains constant? 41. A gas at 65ºC occupies 4.22 L. At what Celsius temperature will the volume be 3.87 L if pressure is held constant? 37 C Gay-Lussac s Law: Answer the following questions. Show all work and units. (pg ) 42. What is the equation for Gay-Lussac s Law? 43. Is this an inverse or direct relationship? Direct goldchemistry.wordpress.com Page 6

7 44. If the pressure doubles, what happens to the temperature? 45. If the temperature is tripled, what happens to the pressure? Triples 46. A gas is held at 320 K and a pressure of 120 kpa. If the pressure is increased to 175 kpa, what is the temperature in K when the volume is held constant? 47. The gas in an aerosol can is at a pressure of 3.00 atm at 25ºC. Directions on the can warn the user not to keep the can in a place where the temperature exceeds 52ºC. What would the gas pressure be in the can at 52ºC? 3.27 atm 48. At 120ºC, the pressure of a sample of nitrogen is 1.07 atm. What will the pressure be at 205ºC assuming constant volume? Combined Gas Law: Answer the following questions. Show all work and units. (pg ) 49. What is the equation for the combined gas law? 50. Explain how the three other gas laws can be derived from the combined gas law. 51. A gas is stored at STP in a container with a volume of 2.35 L. When taken out of storage, the pressure drops to 98 kpa and the temperature increases to 280 K. What is the new volume? 2.49 liters goldchemistry.wordpress.com Page 7

8 52. A student collects 450 ml of HCl, hydrogen chloride gas, at a pressure of 100 kpa and a temperature of 17ºC. What is the volume of the HCl at 0ºC and kpa? 53. A 2.4L mylar balloon is filled with helium gas to a pressure of 107 kpa when the temperature is 22ºC. If the temperature changes to 45ºC and the volume expands to 3.0 L, what will be the pressure of the helium in the balloon? 92.3 kpa Ideal Gas Law: Answer the following questions. Show all work and units. (pg ) 54. Write the Ideal Gas Law. What does each of the variables stand for? a. Gas Law: b. P: c. V: Units: d. N: e. R in atm: R in kpa: f. T: Units: 55. How many moles are in a 15 L container at 20ºC and 2.3 atm? 1.43 moles 56. A chemical reaction produced 98.0 ml of sulfur dioxide gas at STP. What was the mass of the gas produced? 57. If 3.27 moles of hydrogen were produced at 25 C and 105 kpa, what volume would the gas require? goldchemistry.wordpress.com Page 8

9 77.2 liters 58. If 2.4 L of carbon dioxide were produced at 45 C and atm, how much mass would the gas have? 59. If a 5.6 L container of nitrogen gas held 43 grams at 31 C, what pressure would be on the container in kpa? 693 kpa Dalton s Law of Partial Pressures: Answer the following questions. Show all work and units when necessary. (pg ) 60. State Dalton s Law of partial pressures. 61. A gas was collected over water at 308 K with an atmospheric pressure at 1.05 atm. What was the partial pressure of this gas? 0.99 atm 62. Oxygen gas from the decomposition of KClO 3 was collected by water displacement. The atmospheric pressure and the temperature during the experiment were torr and 25.0ºC. What was the partial pressure of oxygen collected? 63. A sample of butane was collected over water. If this occurred at STP, what was the partial pressure of the butane? kpa 64. A sample of propane was collected over water. If this occurred at 25 C and 1.04 atm, what was the partial pressure of the propane? goldchemistry.wordpress.com Page 9

10 Effusion and Diffusion: Answer the following questions. (pg ) 65. Define effusion. Graham s law of effusion states that the larger the molecule, the slower the speed of that molecule. 66. Define diffusion. 67. Of the following molecules, which would move the fastest at the same temperature? Slowest? CH 4, H 2O, O 2, Cl 2, SO 3, NO 2 Slowest: SO3 Fastest: CH4 goldchemistry.wordpress.com Page 10