SparkNotes: Review of Gases: Gases Review Test

1. Which of the following is a correct interpretation of the ideal gas law?

(A)

nPV =

(B)

nPV =

(C)

= PT

(D)

=

2. What is the correct relationship between v_rms,

, and v_p?

(A) v_rms =

= v_p

(B)

< v_p≤v_rms

(C) v_p <

< v_rms

(D) v_rms <

< v_p

3. An isolated container of gas doubles in pressure and triples in volume. By what factor does T change?

(A) 2

(B) 3

(C) 6

(D) -6

4. If the volume of a gas is doubled at constant temperature, the factor by which the pressure increases is:

(A) 2

(B) 1

(C)

(D)

5. A barometer filled with an unknown liquid has a height of 1 m at 1 atm. During stormy weather, the height of the column is observed to rise to 1.3 m. What is the atmospheric pressure?

(A)

atm

(B) 1.3 atm

(C) 1 atm

(D) Cannot be determined

6. Which of the following are possible units of R?

(A)

(B)

(C)

(D)

7.

You take a reading of 760 mm of Hg at 0 degrees Celsius. However, you realize that the volume at the top of the barometer is not a complete vacuum. There is some Hg vapor above the Hg column! If the pressure of Hg is 10 mm Hg, what is the actual atmospheric pressure?

(A) 770 mm Hg

(B) 760 mm Hg

(C) 750 mm Hg

(D) Cannot be determined

8. What are the conditions of STP?

(A) 1 bar, 273 K

(B) 1 bar, 298 K

(C) 1.013×10⁵Pa, 298 K

(D) 1.013×10⁵Pa, 273 K

9. A container contains 32 grams of O₂ gas and 2 grams of H₂ gas. If the total pressure of the vessel is 16 atm, what is the partial pressure of the H₂ gas?

(A) 1 atm

(B) 2 atm

(C) 8 atm

(D) 10 atm

10. As the average radius of a population of gas molecules increases, how does the factor b of van der Waals equation change?

(A) Increase

(B) Stay the same

(C) Decrease

(D) Depends on identity of the gas

11. All of the following are properties of an ideal gas except:

(A) Easily compressible

(B) Individual molecules are assumed to have no volume.

(C) Individual molecules exert attractive forces on one another.

(D) Fills any container in which it is placed

12. The ideal gas law is most valid under these conditions:

(A) High temperature, high pressure

(B) High temperature, low pressure

(C) Low temperature, low pressure

(D) Low temperature, high pressure

13. The reaction

N₂ +2O₂→2NO₂

1 mol of N₂ and 2 mol O₂ react completely in an isolated, rigid container with initial pressure 1 atm. The temperature does not change. What is the pressure inside the container after the reaction has gone to completion?

(A) 1 atm

(B) 3/2 atm

(C) 2/3 atm

(D) 5/2 atm

14.

There are 4.0 mol of gas a in container A at 1.0 atm and 273 K. There are 2.0 mol of gas b in container B at 2.0 atm and 273 K. What is the total volume of containers A and B?

(A) 130 L

(B) 90 L

(C) 110 L

(D) 22.4 L

15.

Is the equation for:

(A) v_p

(B) v_rms

(C)

(D) None of the above

16. For the van der Waals equation:

(P +

)(V - nb) = nRT

The value "b" corrects for:

(A) The volume occupied by the gas molecules

(B) Inelastic collisions between gas molecules

(C) Intermolecular attractions

(D) The Boltzmann constant

17. For the equation PV = nRT, the value of T must be expressed in:

(A) Degrees Celsius

(B) Degrees Fahrenheit

(C) Only positive values of degrees Fahrenheit

(D) An absolute temperature scale

18. Which of the following is not a SI unit

(A) Kilograms

(B) Atmospheres

(C) Newtons

(D) Kelvin

19. A sample of gas has a volume of 22.4 L at a temperature of 273 K. How many moles are in the sample?

(A) 2.0

(B) 1.0

(C) 0.50

(D) Cannot be determined from the information given.

20. The volume of a sample of gas expands five times at constant pressure. By what factor has the absolute temperature changed?

(A) 1/5

(B) 1

(C) 5

(D) Cannot be determined from the information given

21. The following reaction produces H₂O gas:

2H₂ + O₂→2H₂O

64.0 g of O_2 are used and an excess of H₂, and the reaction goes to completion. How many liters of H₂O gas will be generated if the pressure is 2.0 atm and the temperature is 273 K?

(A) 64 L

(B) 22 L

(C) 45 L

(D) 11 L

22. A sample of gas occupies 100 L at STP. If the absolute temperature is halved while all other conditions are constant, what will be the final volume?

(A) 50 L

(B) 100 L

(C) 150 L

(D) 200 L

23. Calculate the v_rms of a sample of O₂ at 300 K.

(A) 484 m/s

(B) 242 m/s

(C) 141 m/s

(D) 9.8 m/s

24. A closed jar contains 2 moles of O₂ and 3 moles of N₂. What is the ratio of the partial pressure of the O₂ over the total pressure in the jar?

(A) 0.1

(B) 0.2

(C) 0.4

(D) 0.6

25. The rate of effusion of gas A is four times that of gas B. What is

?

(A) 1/16

(B) 1/2

(C) 2

(D) 16

26.

The Hg containing dish of the barometer is replaced with one four times its diameter. By what factor does H change?

(A) 1/2

(B) 2

(C) 4

(D) H does not change.

27. The density of a certain gas at STP is 1.43 g/L. What is the identity of the gas?

(A) H₂

(B) O₂

(C) CO₂

(D) Cl₂

28. One end of a mercury manometer is open to the atmosphere (P_atm = 760mmHg). The other end is connected to a 1 mol sample of CH₄ that is at 273 K and occupies 22.4 L. What is the height of the mercury column?

(A) 760 mm

(B) 560 mm

(C) 120 mm

(D) 0 mm Hg

29. The Maxwell-Boltzmann distribution graph plots:

(A) Pressure vs. Volume

(B) Mean free path vs. time

(C) Mean free path vs. velocity

(D) The velocity distribution of a population of gas molecules.

30. James the giant has big shoes to fill. His shoes have a total area of 20m² in contact with the ground. Unfortunately, James' feet are not so big. Barefoot, his weight is spread over 1m². What is the ratio of the pressure he exerts on the ground barefoot over the pressure he exerts with his shoes on?

(A) 40

(B) 20

(C) 10

(D) 1/20

31. The "air" in airbags is generated via the decomposition of solid NaN₃:

2NaN₃→2Na + 3N₂

2/3 mole of solid NaN₃ are completely decomposed at a temperature of 300 K. In order for the final pressure in the airbag to be 1.2 atm, what must the final volume of the bag be in L? Assume that the Na takes up no appreciable volume. R = 0.0821

.

(A) 11 L

(B) 15 L

(C) 21 L

(D) 34 L

32. A sample of an ideal gas is compressed at constant temperature. What happens to the average kinetic energy of the molecules?

(A) The molecules bounce into the walls more often. Thus average kinetic energy decreases.

(B) When in a confined space, molecules move slower. Average kinetic energy decreases.

(C) Average kinetic energy is solely dependent on pressure. As pressure rises, so does the average kinetic energy.

(D) Average kinetic energy is solely dependent on temperature. The temperature does not change, so the average kinetic energy stays constant.

33. A piston compresses a gas at constant temperature. Initially the gas occupied 1 L and was at a pressure of 1 atm. After compression, the gas occupies 0.1 atm. What is the pressure of the compressed gas?

(A) 0.1 atm

(B) 1 atm

(C) 10 atm

(D) 100 atm

34. A collaborator from a foreign country reports that the value of R as 8

. He has probably used units of "woozle" for which of the following variables:

(A) Pressure

(B) Volume

(C) Temperature

(D) Mole fraction

35. Avogadro's number is:

(A) 8.314

(B) 0.0821

(C) 1.38×10^-23

(D) 6.02×10²³

36. What is

if both samples of gas are at the same temperature?

(A) 2

(B)

(C) 1/2

(D)

37. The following Maxwell-Boltzmann distribution plot was measured for two gases A and B at the same temperature:

Which gas has the greater molecular mass?

(A) Gas A

(B) Gas B

(C) Their molecular masses are equal

(D) Cannot be determined

38. A rigid container holds a mixture of gases. Within this mixture, the partial pressure of O₂ is 400 torr. If an additional quantity of N₂ gas is injected into the container such that the total pressure of the container rises by 760 torr, what is the change in the partial pressure of O₂? Assume that the temperature of the container's contents stays constant.

(A) - 100 torr

(B) 0 torr

(C) + 100 torr

(D) + 760/400 torr

39. If the pressure of a gas doubles and the temperature quadruples, by what factor does the volume change?

(A) 1/2

(B) 1

(C) 2

(D) 4

40. Which of the following are possible units for pressure?

(A)

(B)

(C)

(D)

41. The following Maxwell-Boltzmann distribution plot was measured for a gas at two temperatures A and B:

What is the relationship between A and B?

(A) A > B

(B) A < B

(C) A = B

(D) Cannot be determined

42. For the following calculation of v_rms, the molar mass (MM) should be expressed in what units?

v_rms	=
	=	sqrt

(A) lb/mol

(B) g/mol

(C) kg/mol

(D) slugs/mol

43. By what significant numerical value are Boltzmann's constant (k) and the gas constant (R) related?

(A) The acceleration due to gravity g

(B) The speed of light, c

(C) Avogadro's number, N_A

(D) The mass of a single C-12 atom

44. The pressure of a gas is tripled while the volume is halved. By what factor does the temperature increase?

(A) 1/2

(B) 2/3

(C) 3/2

(D) 2

45. The gas constant R:

(A) Is unitless

(B) Varies with varying temperature, pressure, and volume.

(C) Is the foundation of Charle's law

(D) Has units of (pressure * volume) over (mol * absolute temperature)

46. One end of a manometer is sealed off to a vacuum. The other end of the manometer is connected to a pressurized gas. The height of the liquid column is indicative of:

(A) The atmospheric pressure

(B) The pressure of the gas

(C) The difference between the atmospheric pressure and the pressure of the gas

(D) The dimensions of this particular manometer

47. A sample of O₂ and a sample of N₂ both have a temperature of 330 K. What is the ratio of the average kinetic energy of the O₂ over that of the N₂?

(A) 28/32

(B) 1

(C) 32/28

(D) Cannot be determined

48. The density of a gas at STP is 0.089 g/L. What is the molar mass of the gas?

(A) 4.0 g/mol

(B) 2.0 g/mol

(C) 1.0 g/mol

(D) Cannot be determined from the given data

49. The following Maxwell-Boltzmann distribution plot was measured for two gases A and B at temperatures T_A and T_B:

Which gas has the greater molar mass?

(A) Gas A

(B) Gas B

(C) MM Gas A = MM Gas B

(D) Cannot be determined from the given data

50. Gaseous methane (CH₄) burns completely in gaseous oxygen to produce carbon dioxide gas and water vapor.

CH₄ +2O₂→CO₂ + 2HOH

2 mole of CH₄ and 4 moles of O₂ completely react in a closed vessel. If temperature and volume are constant, by what factor will pressure increase?

(A) 1/2

(B) 1

(C) 2

(D) Cannot be determined from the given data.

Review of Organic Chemistry IV

Gases Review Test