1. Bell Work 1.Convert 15.3 atm to kPa 2.Convert 96.3 L of a gas at STP to moles. 3.What is the temperature and pressure at STP? 4.A scientist is trying to determine the pressure of a system that is made up of 4 gases. One gas has a pressure of 20 kPa. Another gas has a pressure of 5 kPa. The remaining two gases have a pressure of 2.5 kPa. What is the total pressure? 5.A system originally has a pressure of 25.2 kPa, a volume of 15.1 L and a temperature of 45.5 ˚C. What is the new volume if the pressure is decreased to 20.0 kPa and the temperature is increased to 60 ˚C? 6.How many moles are in a system that has a pressure of 2.5 atm, a volume of 33.3 L and a temperature of 75.2 ˚C?

2. Bell Work Get your homework out and leave it on your desk Get with your group and work on the diffusion lab. After which we will go over homework and then take a reality check. If you finish with this lab, use the time to complete the other labs that you may not have completed yet. If that is finished, work on the study guide and review for tomorrow’s test. After reality check, we will review for tomorrow’s test.

3. Homework Answers 1.4.69 2.1501 m/s 3.17.75 g/mol 4.0.485; slower 5.128 g/mol; HI 6.64 g/mol; SO 2 7.1920 m/s

4. Reality Check 1)In comparing the rates of diffusion of CO 2 with that of Kr, which gas will diffuse faster? 2)To two decimal places, what will v A /v B (treat this as x) be equal to if CO 2 is considered to be A and Kr is considered to be B. 3)What is the molar mass of a gas if it diffuses at a rate of 647 m/s while chlorine (Cl 2 ) gas diffuses at 840 m/s at the same temperature? After you are finished, continue working on the lab.

5. Make Up Reality Check 1)In comparing the rates of diffusion of NO with that of F 2, which gas will diffuse faster? 2)To two decimal places, what will v A /v B (treat this as x) be equal to if NO is considered to be A and F 2 is considered to be B. 3)What is the molar mass of a gas if it diffuses at a rate of 925 m/s while bromine (Br 2 ) gas diffuses at 620 m/s at the same temperature?

6. Unit 9 Review Gases

7. The Game Board 12345 678910 1112131415 1617181920 2122232425 2627282930 3132333435

8. 1 Calculate the approximate volume of a 2.50 mol sample of gas at -8.0°C and a pressure of 3.50 atm. 15.5 L

9. 2 In the reaction N 2 (g) + 3H 2 --> 2NH 3 (g), the volume ratio of H 2 to N 2 is___________ 3 to 1

10. 3 A pressure of 165 kPa is equal to _____ atm. 1.63

11. 4 What does the constant bombardment of gas molecules against the inside of a container cause? Pressure

12. 5 What happens to the volume of a gas during compression? The Volume Decreases

13. 6 A sample of a gas has a pressure of 2.25 atm, a volume of 650 mL and a temperature of 36°C. What would the volume of the gas be if the pressure is increased to 3.20 atm and the temperature is decreased to 31°C? 449.6 mL

14. 7 What temperature is needed to pressurize a 27.3 L container with 6.34 moles of air to 564.8 kPa? 292.5 K

15. 8 When pressure, volume, and temperature are known, the ideal gas law can be used to calculate ______________. Molar amount (moles)

16. 9 According to the diagram to the right, what PV/nRT value do ideal gases have all the time? 1.0

17. 10 What is the SI unit of pressure? Pascal

18. 11 If a gas with an odor is released in a room, it quickly can be detected across the room because it ______________. Diffuses

19. 12 A pressure of 355000 Pa is equal to _____ psi. 51.5

20. 13 The principle that under similar pressures and temperatures, equal volumes of gases contain the same number of molecules is attributed to ________________. Avogadro

21. 14 Nitrogen reacts with hydrogen to make ammonia [N 2 (g) + 3H 2 (g) --> 2NH 3 (g)]. If one needs to produce 4 L of ammonia, how many liters of nitrogen are needed? 2 L

22. 15 A sample of a gas occupies a volume of 1.1 L at 33°C. What temperature is needed to increase the volume of the gas to 1.9 L, if the pressure remains constant? 528.5 K or 255°C

23. 16 A 10.5 L sample of a gas has a mass of 95.9 g at 7.6 atm and 35°C. What is the molar mass of the gas? (Hint: divide the given mass by n). 30.4 g/mol

24. 17 According to the diagram to the right, at what pressure do all the gases most resemble an ideal gas? 0 atm

25. 18 A pressure of 560 mmHg is equal to _____ kPa. 74.7

26. 19 Who is accredited with the idea that in a reaction, two volumes of hydrogen gas will combine with one volume of oxygen gas to produce two volumes of water vapor? Gay-Lussac

27. 20 The pressure of each gas in a mixture is called the ____________________ pressure. Partial

28. 21 A sample of a gas has a pressure of 567 mmHg at 23°C. What would the gas pressure be at 41°C, if the volume remains constant? 601 mmHg

29. 22 To two decimal places, what will v A /v B be equal to if N 2 is considered to be gas A and NO is considered to be gas B. (A diffusion problem) 1.03

30. 23 Standard temperature and pressure for a gas is ____________________ 0°C and 1 atm.

31. 24 The total pressure of a system of four gases is 35 atm. The first gas has a pressure of 5 atm. The second gas has a pressure of 8 atm. The remaining two pressures are the same. What is the partial pressure of the other two gases? 11

32. 25 Charles’s law is the direct relationship between ____________________ and volume. Temperature

33. 26 What is the molar mass of a gas if it diffuses at a rate of 258 m/s while Iodine gas diffuses at 125 m/s at the same temperature? 29.7 g

34. 27 2H 2 O(l) + electricity  2H 2 (g) + O 2 (g) What mass of H 2 O is needed to create 15.64 L of O 2, if the temperature is 25°C and the pressure is 1.2 atm? 27.6 g

35. 28 The average kinetic energy of random motion is proportional to the temperature in what unit? Kelvin

36. 29 A sample of oxygen occupies 350 mL when the pressure is 5 atm. At constant temperature, what volume does the gas occupy when pressure falls to 3 atm? 583 mL

37. 30 Who developed the concept that the total pressure of a mixture of gases is the sum of their partial pressures? Dalton

38. 31 What is the theory that explains that the behavior of physical systems depends on the combined actions of the molecules constituting the system? Kinetic Molecular Theory

39. 32 A mixture of gases with a pressure of 800.0 mm Hg contains 60% nitrogen and 40% oxygen by volume. What is the partial pressure of oxygen in this mixture? 320 mm Hg

40. 33 Line D represents water. If the atmospheric pressure in a flask is lowered to 70 kPa, water would boil at what temperature? 92  C

41. 34 T 1 = 76  C P 1 = 4 atmV 1 = 560 mL T 2 = 92  C P 2 = 2 atmV 2 = ? 1171 mL

42. 35 The rate of diffusion of a gas depends on the ____________ of the gas. Molar Mass