1. Gas Laws Review

2. (1)
A sample of helium has a volume of 3 liters when the pressure is 500 torr. What volume does the gas occupy at 300 torr?

3. (1) ANSWER
5 L

4. (2)
How are pressure and temperature related?

5. (2) ANSWER
Directly proportional

6. (3)
How would you convert a Celsius temperature to a Kelvin temperature?

7. (3) ANSWER
Add 273

8. (4)
A child receives a balloon filled with 2.30 L of helium from a vendor at an amusement park. The temperature outside is 311 K. What will be the volume of the balloon when the child brings it home to an air-conditioned house at 295 K?

9. (4) ANSWER
2.18 L

10. (5)
A small 2.00 L fire extinguisher has an internal pressure of kPa at 25.0°C. What volume of methyl bromide, the fire extinguisher’s main ingredient, is needed to fill an empty fire extinguisher at standard pressure if the temperature remains constant?

11. (5) ANSWER
10.0 L
(9.97 L if converted to atm to solve)

12. (6)
At a deep sea station 200. m below the surface of the Pacific Ocean, workers live in a highly pressurized environment. How many liters of gas at STP on the surface (which is at atmospheric pressure) must be compressed to fill the underwater environment with 2.00 x 107 liters of gas at 20.0 atm?

13. (6) ANSWER
4.00 x 108 L

14. (7)
How are pressure and volume related?

15. (7) ANSWER
Inversely proportional

16. (8)
Suppose you have a 500. mL container that contains mol of oxygen gas at 25.0 °C. What is the pressure inside the container?

17. (8) ANSWER
2.45 atm

18. (9)
How many grams of oxygen gas in a 10.0 L container exert a pressure of 97.0 kPa at a temperature of 25.0 °C ?

19. (9) ANSWER
12.5 g O2

20. (10)
A helium balloon has a volume of 500. mL at STP. What will be it new volume if the temperature is increased to 325 K and its pressure is increased to 125 kPa?

21. (10) ANSWER
0.483 L

22. (11)
The air in a balloon has a volume of 3.00 L and exerts a pressure of 101 kPa at 300.0K. What pressure does the air in the balloon exert if the temperature is increased to K and the air is allowed to expand to 15.0 L?

23. (11) ANSWER
26.9 kPa

24. (12)
How many moles of gas occupy 98 L at a pressure of 2.8 atm and a temperature of 292 K?

25. (12) ANSWER
11 moles

26. (13) *HONORS*
If 5.0 moles of O2 and 3.0 moles of N2 are placed in a 30.0 L tank at a temperature of 25oC, what will the pressure of the resulting mixture of gases be?

27. (13) ANSWER
6.5 atm

28. (14) *HONORS*
The mole fraction of helium in a tank full of helium, neon, and krypton gases is What is the total pressure in the tank if the partial pressure of helium is atm?

29. (14) ANSWER
1.95 atm

30. (15)
How are volume and temperature related?

31. (15) ANSWER
Directly proportional

32. (16)
What is the device called that measures atmospheric pressure?

33. (16) ANSWER
Barometer

34. (17) 2 pts
Who invented the barometer?

35. (17) ANSWER
Evangelista Torricelli

36. (18)
How are volume and number of moles related?

37. (18) ANSWER Directly proportional
*KNOW HOW TO SOLVE PROBLEMS W/AVOGADRO’S LAW

38. (19)
What is the difference between STP and standard conditions?

39. (19) ANSWER STP is 273 K (OoC) and 1 atm
Standard conditions is 298 K (25oC) and 1 atm

40. (20) *HONORS*
How many liters of hydrogen gas can be produced at 290. K and 99.0 kPa if 17.0 g of potassium metal are reacted with water?
2K + 2 H2O 2 KOH + H2

41. (20) ANSWER
5.30 L

42. (21) *HONORS*
One industrial method for producing nitric acid involves dissolving nitrogen dioxide in water.
3 NO2 (g) + H2O (l)  2HNO3 (l) + NO (g)
What mass of water will react with a mL container of nitrogen dioxide at 25.0 °C and 60.0 kPa?

43. (21) ANSWER

44. (22)
TRUE OR FALSE: Gas molecules strongly attract one another.

45. (22) ANSWER
False

46. (23)
TRUE OR FALSE: At higher temperatures, gases have lower kinetic energies

47. (23) ANSWER
False

48. (24) 2 points
Which 2 properties of gases explain why you can smell air freshener across a room.

49. (24) ANSWER (1) Gases diffuse through other gases
(2) Gases uniformly fill their containers

50. (25) 2 pts
At STP a tank is filled with 22.4-L nitrous oxide. How many moles of gas are in the tank when the volume changes to 17.4 L?

51. (25) ANSWER
0.777 mol

52. (26) 3 points
A 4.25 g sample of fluorine at STP is in a sealed container. When the pressure changes to 0.25 atm and the temperature drops to 200. K, what is the new volume?

53. (26) ANSWER
7.3 L
7.4 L acceptable

54. (27) 2 points
The pressure of a gas changes form 120 kPa to 50 kPa. The volume changes from 45 L to 40. L. If the initial temperature is 81oC, what is Mrs. Ward’s favorite number?

55. (27) ANSWER 2

56. (28)
What volume of mol of carbon dioxide gas is present at STP?

57. (28) ANSWER
22.4 L