College Chem Test #2

Which one of the following gases would deviate the least from ideal gas behavior? * A) Ne B) CH3Cl C) Kr D) CO2 E) F2

A) Ne

A Temperature of 0C is equivalent to?

273K

A 4.50 mol sample of a gas occupies a volume of 34.6 L at a particular temperature and pressure. What volume in L does 2.50 mol of the gas occupy at these same conditions of pressure and temperature? (A)19.2 (B)62.3 (C) 0.016 (D)22.4 (E) 0.325

(A)19.2

Gases tend to have very low densities because (A)a small number of gas particles occupy a large volume (B) a large number of gas particles occupy a small volume (C) a small number of gas particles occupy a small volume (D)they are lighter than liquids and solids

(A)a small number of gas particles occupy a large volume

The greater the mass or velocity of a particle, the ________ the kinetic energy. (A)greater (B)lesser (C) same as (D)Impossible to determine

(A)greater

According to the kinetic-molecular theory, particles of matterare in constant motion (A)have different shapes (B)have different colors (C) are always fluid

(A)have different shapes

21. Which of these changes would NOT cause an increase in the pressure of a gaseous system? (A) The container is made larger. (B) Additional amounts of the same gas are added to the container. (C) The temperature is increased. (D) Another gas is added to the container.

(B) Additional amounts of the same gas are added to the container.

33. A sample of an ideal gas (3.00 L) in a fixed container at 25.0°C and 76.0 torr is heated to 300°C. The pressure of the gas at this new temperature is __________ torr. (A)912 (B)146 (C) 76.5 (D)39.5 (E) 2.53x10-2

(B)146

What happens to the volume of a gas during compression? (A)The volume increases (B)The volume decreases (C) The volume remains constant (D)It is impossible to tell because all gases are different

(B)The volume decreases

At high temperatures the particles of a gas (A)move slower and hit the walls of their container less often. (B)move faster and hit the walls of their container more frequently (C) move faster and hit the walls of their container less frequently (D)don't move at all and don't hit the walls of their container.

(B)move faster and hit the walls of their container more frequently

According to the kinetic-molecular theory, which substances are made of particles? (A)Ideal gases only (B)All gases (C) All matter (D)All matter except solids

(C) All matter

According to the kinetic-molecular theory, particles of a gas (A)attract each other but do not collide (B) repel each other and collide (C) neither attract nor repel each other but collide (D)neither attract nor repel each other and do not collide

(C) neither attract nor repel each other but collide

25. A sample of gas in a 10.0-L container exerts a pressure of 565 mm Hg. The pressure exerted by the gas if the volume is changed to 15.0 L at constant pressure is _______atm. (A)1.11 (B)848 (C) 2.02 (D)0.496 (E) 377

(D)0.496

24. Consider a 1.5-L sample of gas. What was its initial pressure when its volume is compressed to 0.95L at a new pressure of 2.5 atm? (A)0.63 (B)3.9 (C) 3.6 (D)1.6 (E) 1.3

(D)1.6

The kinetic-molecular theory explains the behavior of (A)gases only (B) solids and liquids (C)liquids and gases (D)solids, liquids and gases

(D)solids, liquids and gases

When gas molecules collide, kinetic molecular theory predicts (A)the collisions are inelastic and there is less kinetic energy after the collision (B)the collisions are perfectly elastic and there is an more kinetic energy after the collision. (C)the collisions are so hard the gas molecules break apart. (D)the collisions are perfectly elastic and there is no net loss of kinetic energy.

(D)the collisions are perfectly elastic and there is no net loss of kinetic energy.

13. Gases are characterized by (A) strong intermolecular interactions. (B)Intermolecular interactions that are stronger than those found in solids. (C) no intermolecular interactions present particles. (D)weak intermolecular interactions.

(D)weak intermolecular interactions.

20. Which of the following equations shows an incorrect relationship between pressures given in terms of different units? A) 1.20 atm = 122 kPa B) 152 mm Hg = 2.03x104 Pa 1.0 torr=2.00mmHg

1.0 torr=2.00mmHg

28. A balloon originally had a volume of 4.39 L at 44°C and a pressure of 729 torr. The balloon must be cooled to __________°C to reduce its volume to 3.78 L (at constant pressure). * A) 0 B) 38 C) 72.9 D) 273 E) 546

A) 0

31. A 2.25 sample of gas occupies 57.9 L. How many moles of gas are present when the gas occupies 30.0 L? A) 1.22 B) 0.82 C) 1.35 D) 1.41 E) 57.9

A) 1.22

37. A sample of gas at 38°C occupies a volume of 2.97 L and exerts a pressure of 3.14 atm. The gas is heated to 118°C and the volume is decreased to 1.04 L. The new pressure exerted by the gas is _____ atm. A) 11.3 B) 27.8 C) .036 D) 7.14 E) 2.11

A) 11.3

34. A sample of hydrogen gas in a closed container has a temperature of 37oC and a pressure of 2 atm. What will be the pressure if the sample is heated to 127oC? A) 2.58 atm B) 3.47 atm C) 5.21 atm D) 6.77 atm

A) 2.58 atm

73. Which of the following is not part of the kinetic-molecular theory? A) Atoms are neither created nor destroyed by ordinary chemical reactions. B) Attractive and repulsive forces between gas molecules are negligible. C) Gases consist of molecules in continuous, random motion. D) Collisions between gas molecules do not result in the loss of energy. E) The volume occupied by all of the gas molecules in a container is negligible compared to the volume of the container.

A) Atoms are neither created nor destroyed by ordinary chemical reactions.

. A gas is considered "ideal" if one mole of it in a one-liter container exerts a pressure of exactly 1 atm at room temperature. A) False B) True

A) False

84. An ideal gas differs from a real gas in that the molecules of an ideal gas _______. ** A) have no attraction for one another B) have appreciable molecular volumes C) have a molecular weight of zero D) have no kinetic energy E) have an average molecular mass

A) have no attraction for one another

15. A gas at a pressure of 10.0 Pa exerts a force of __________ N on an area of 5.5 m2 A) 55 B) 0.55 C) 5.5 D) 1.8 E) 18

B) 0.55

9. A temperature of -273oC is equivalent to? A) -100 K B) 0K C) 100 K D) 273 K E) 373 K

B) 0K

38. A sample of gas at 24°C occupies a volume of 3.45 L and exerts a pressure of 2.10 atm. The gas is cooled to -12°C and the pressure is increased to 5.20 atm. The new volume the gas occupies is_______L. A) 0.820 B) 1.22 C) 0.82

B) 1.22

45. Standard temperature and pressure (STP), in the context of gases, refers to __________. A) 298 K and 1 atm B) 273 K and 1 atm C) 298K and 1 torr D) 273 K and 1 pascal E) 273 K and 1 torr

B) 273 K and 1 atm

26. A gas originally at 27°C and 1.00 atm pressure in a 3.9 L flask is cooled at constant pressure until the temperature is 11°C. The new volume of the gas is __________ L. A) 0.27 B) 3.7 C) 3.0 D) 4.1 E) 0.24

B) 3.7

39. A gas under 25 atm pressure occupies 35.0 L at 127oC. What is the volume of the gas under standard conditions (1 atm, 0oC)? A) 0 L B) 597.2 L C) 1880.9 L D) 3000 L

B) 597.2 L

In ideal gas equation calculations, expressing pressure in Pascals (Pa), necessitates the use of the gas constant, R, equal to __________. A) 0.08206 atm L mol-1 K-1 B) 8.314 J mol-1K-1 C) 62.36 L torr mol-1K-1 D) 1.98 cal mol-1 K-1 E) none of the above

B) 8.314 J mol-1K-1

19. Which statement about atmospheric pressure is false? A) As air becomes thinner, its density decreases. B) Air actually has weight. C) With an increase in altitude, atmospheric pressure increases as well. D) The colder the air, the lower the atmospheric pressure. E) Atmospheric pressure prevents water in lakes, rivers, and oceans from boiling away.

B) Air actually has weight.

74. Of the following gases, ___ will have the greatest rate of effusion at a given temperature. A) NH3 B) CH4 C) Ar D) HBr E) HCl

B) CH4

75. At 333 K, which of the pairs of gases below would have the most nearly identical rates of effusion? A) N2O and NO2 B) CO and N2 C) N2 and O2 D) CO and CO2 E) NO2 and N2O4

B) CO and N2

27. If the temperature is lowered from 60°C to 30°C, the volume of a fixed amount of gas will be one half the original volume assuming the pressure is kept constant. A) True B) False

B) False

The main component of air is oxygen. A) True B) False

B) False

92. Of the following, __________ has the odor of rotting eggs. A) NH3 B) H2S C) CO D) NO2 E) HCN

B) H2S

. The density of air at STP is 1.285 g/L. Which of the following cannot be used to fill a balloon that will float in air at STP? * A) CH4 B) NO C) Ne D) NH3 E) HF

B) NO

29. Of the following, only __________ is impossible for a gas. A) V1/T1 = V2/T2 B) V1T1=V2T2 C) V1/V2 = T1/T2 D) V2 = (T2/T1)V1 E) V1/V2 = T1/T2 = 0

B) V1T1=V2T2

89. One significant difference between gases and liquids is that _________ * A) a gas is made up of molecules B) a gas assumes the volume of its container C) a gas may consist of both elements and compounds D) gases are always mixtures E) All of the above answers are correct.

B) a gas assumes the volume of its container

One significant difference between gases and liquids is that __________. A) a gas is made up of molecules B) a gas assumes the volume of its container C) a gas may consist of both elements and compounds D) gases are always mixtures E) All of the above answers are correct.

B) a gas assumes the volume of its container

85. A real gas will behave most like an ideal gas under conditions of __________. * A) high temperature and high pressure B) high temperature and low pressure C) low temperature and high pressure D) low temperature and low pressure E) STP

B) high temperature and low pressure

72. According to kinetic-molecular theory, if the temperature of a gas is raised from 100°C to 200°C, the average kinetic energy of the gas will __________. A) double B) increase by a factor of 1.27 C) increase by a factor of 100 D) decrease by half E) decrease by a factor of 100

B) increase by a factor of 1.27

35. As the temperature of the gas in a balloon decreases _____. A) the volume increase. B) the average kinetic energy of the gas decreases C) the pressure increases D) All of the above

B) the average kinetic energy of the gas decreases

23. A sample of a gas (5.0 mol) at 1.0 atm is expanded at constant temperature from 10 L to 15 L. The final pressure is __________ atm. A) 1.5 B) 7.5 C) 0.67 D) 3.3 E) 15

C) 0.67

A temperature of 373 K is equivalent to? A) -100oC B) 0oC C) 100oC D) 273oC E) 373oC

C) 100oC

46. How many molecules are there in 4.00 L of oxygen gas at 500°C and 50.0 torr? A) 6.02x1023 B) 2.5x1023 C) 2.5x1021 D) 3.5x1021 E) 3.01x1023

C) 2.5x10^21

The pressure exerted by a column of liquid is equal to the product of the height of the column times the gravitational constant times the density of the liquid, P = ghd. How high a column of water, (d=1.0g/ml) would be supported by a pressure that supports a 713 mm column of mercury, (d=13.6 g/ml)? A) 14 mm B) 52 mm C) 713 mm D) 1.2 x 104 mm E) 9.7x103mm

C) 713 mm

16. A pressure of 1.00 atm is the same as a pressure of __________ of mm Hg. A) 193 B) 101 C) 760 D) 29.9 E) 33.0

C) 760

93. Molecular compounds of low molecular weight tend to be gases at room temperature. Which of the following is most likely not a gas at room temperature? A) Cl2 B) HCl C) LiCl D) H2 E) CH4

C) LiCl

91. Of the following, __________ has a slight odor of bitter almonds and is toxic. A) NH3 B) N2O C) CO D) CH4 E) HCN

E) HCN

44. How many moles of gas are there in a 45.0 L container at 25.0°C and 500.0 mm Hg? A) 0.630 B) 6.11 C) 18.4 D) 1.21 E) 207

D) 1.21

43. The molar volume of a gas at STP is _________ L. A) 0.08206 B) 62.36 C) 1.00 D) 22.4 E) 14.7

D) 22.4

48. If 50.75 g of a gas occupies 10.0 L at STP, 129.3 g of the gas will occupy __________ L at STP. A) 3.92 B) 50.8 C) 12.9 D) 25.5 E) 5.08

D) 25.5

30. If 3.21 mol of a gas occupies 56.2 L at 44°C and 793 torr, 5.29 mol of this gas occupies __________ L under these conditions. * A) 14.7 B) 61.7 C) 30.9 D) 92.6 E) 478

D) 92.6

42. The volume of an ideal gas is zero at __________. A) 0°C B) -45°F C) -273 K D) -363 K E) -273°C

E) -273°C

40. At a temperature of __________ °C, 0.444 mol of CO gas occupies 11.8 L at 889 torr. A) 379 B) 73 C) 14 D) 32 E) 106

E) 106

In a Torricelli barometer, a pressure of one atmosphere supports a 760 mm column of mercury. If the original tube containing the mercury is replaced with a tube having twice the diameter of the original, the height of the mercury column at one atmosphere pressure is __________ mm. A) 380 B) 760 C) 1.52x103 D) 4.78 x 103 E) 121

E) 121

22. A sample of gas (24.2 g) initially at 4.00 atm was compressed from 8.00 L to 2.00 L at constant temperature. After the compression, the gas pressure was __________ atm. A) 4.00 B) 2.00 C) 1.00 D) 8.00 E) 16.0

E) 16.0

36. A sample of a gas originally at 25°C and 1.00 atm pressure in a 2.5 L container is allowed to expand until the pressure is 0.85 atm and the temperature is 15°C. The final volume of the gas is ___ L. A) 3.0 B) 0.38 C) 2.6 D) 2.1 E) 2.8

E) 2.8

90. Which of the following statements about gases is false? * A) Gases are highly compressible. B) Distances between molecules of gas are very large compared to bond distances within molecules. C) Non-reacting gas mixtures are homogeneous. D) Gases expand spontaneously to fill the container they are placed in. E) All gases are colorless and odorless at room temperature.

E) All gases are colorless and odorless at room temperature.

88. The Van der Waals equation for real gases recognizes that __________. ** A) gas particles have non-zero volumes and interact with each other B) molar volumes of gases of different types are different C) the non-zero volumes of gas particles effectively decrease the amount of "empty space" between them D) the molecular attractions between particles of gas decreases the pressure exerted by the gas E) All of the above statements are true.

E) All of the above statements are true.

71. The kinetic-molecular theory predicts that pressure rises as the temperature of a gas increases because __________. A) the average kinetic energy of the gas molecules decreases B) the gas molecules collide more frequently with the wall C) the gas molecules collide less frequently with the wall D) the gas molecules collide more energetically with the wall E) the gas molecules collide more frequently and more energetically with the wall

E) the gas molecules collide more frequently and more energetically with the wall

87. Which noble gas is expected to show the largest deviations from the ideal gas behavior? * A) helium B) neon C) argon D) krypton E) xenon

E) xenon