Question 1

A mixture of two ideal gases A and B is in thermal equilibrium at 600 K.A molecule of A has one-fourth the mass of a molecule of B and the rms speed of molecules of A is 400 m/s.Determine the rms speed of molecules of B.

Accepted Answer

A) 100 m/s 
B) 200 m/s 
C) 400 m/s 
D) 800 m/s 
E) 1600 m/s

Question 2

A canister containing 115 kg of an ideal gas has a volume of 6.5 m³.If the gas exerts a pressure of 4.0 × 10⁵ Pa,what is the rms speed of the molecules?

Accepted Answer

A) 260 m/s 
B) 180 m/s 
C) 310 m/s 
D) 390 m/s 
E) 420 m/s

Question 3

Complete the following statement: The pressure exerted by a monatomic,ideal gas on the walls of its containing vessel is a measure of

Accepted Answer

A) the molecular kinetic energy per unit volume. 
B) the average random kinetic energy per molecule. 
C) the temperature of the gas,regardless of the volume of the vessel. 
D) the total internal energy of the gas,regardless of the volume of the vessel. 
E) the momentum per unit volume.

Question 4

Which one of the following statements concerning diffusion is true?

Accepted Answer

A) Diffusion occurs only in gases. 
B) Diffusion occurs in solids and fluids. 
C) Diffusion is described by Boyle's law. 
D) The SI unit for the diffusion constant D is m/s². 
E) Diffusion occurs when molecules move from regions of lower concentration to regions of higher concentration.

Question 5

Complete the following statement: The atomic mass unit (u)is defined so that 1 u is exactly equal to the mass of

Accepted Answer

A) a single hydrogen atom. 
B) 1/4 of a helium molecule. 
C) 1/16 of an oxygen-16 atom. 
D) 1/32 of an oxygen molecule. 
E) 1/12 of a carbon-12 atom.

Question 6

Complete the following statement: The absolute temperature of an ideal gas is directly proportional to

Accepted Answer

A) the number of molecules in the sample. 
B) the average momentum of a molecule of the gas. 
C) the average translational kinetic energy of the gas. 
D) the amount of heat required to raise the temperature of the gas by 1 C°. 
E) the relative increase in volume of the gas for a temperature increase of 1 C°.

Question 7

An ideal gas is confined within a closed cylinder at a pressure of 2.026 × 10⁵ Pa by a piston.The piston moves until the volume of the gas is reduced to one-ninth of the initial volume.What is the final pressure of the gas when its temperature returns to its initial value?

Accepted Answer

A) 9.117 × 10⁵ Pa 
B) 6.447 × 10⁵ Pa 
C) 4.559 × 10⁵ Pa 
D) 3.102 × 10⁵ Pa 
E) 1.823 × 10⁶ Pa

Question 8

On a cold day (-3 °C),the gauge pressure on a tire reads 2.0 atm.If the tire is heated to 27 °C,what will be the absolute pressure of the air inside the tire?

Accepted Answer

A) 2.0 atm 
B) 2.2 atm 
C) 2.4 atm 
D) 2.9 atm 
E) 3.3 atm

Question 9

What is the mass of 3.0 moles of hydrogen molecules,H₂? (atomic mass of H = 1 u)

Accepted Answer

A) 0.0060 g 
B) 0.0030 kg 
C) 0.0090 kg 
D) 0.015 kg 
E) 0.030 kg

Question 10

How many moles are in a 0.53-kg sample of sulphur dioxide,SO₂? (atomic masses: C = 32 u;O = 16 u)

Accepted Answer

A) 5.2 
B) 8.3 
C) 48 
D) 1.6 × 10⁴ 
E) 5.0 × 10²⁴

Question 11

Which one of the following statements best explains why gases are not commercially sold by volume?

Accepted Answer

A) Gas volume is negligible. 
B) Gas volume is difficult to measure. 
C) Gas volume depends on the type of gas. 
D) Gases have comparatively low densities. 
E) Gas volume depends on temperature and pressure.

Question 12

A sealed container has a volume of 0.020 m³ and contains 15.0 g of molecular nitrogen (N₂),which has a molecular mass of 28.0 u.The gas is at 525 K.What is the absolute pressure of the nitrogen gas?

Accepted Answer

A) 3.9 × 10-¹⁹ Pa 
B) 4.3 × 10-⁵ Pa 
C) 1.2 × 10⁵ Pa 
D) 1.9 × 10⁵ Pa 
E) 4.3 × 10⁶ Pa

Question 13

A physics student looks into a microscope and observes that small particles suspended in water are moving about in an irregular motion.Which of the following statements is the best explanation for this observation?

Accepted Answer

A) Water molecules strike the particles giving them the same average kinetic energy as the water. 
B) The particles are carried by convection currents in the water. 
C) The small particles may be considered a fluid;and thus,move about randomly. 
D) The actual motion is regular,but the speeds of particles are too large to observe the regular motion. 
E) The particles are moving to be uniformly distributed throughout the volume of the water.

Question 14

Complete the following statement: The internal energy of an ideal monatomic gas is

Accepted Answer

A) proportional to the pressure and inversely proportional to the volume of the gas. 
B) independent of the number of moles of the gas. 
C) proportional to the Kelvin temperature of the gas. 
D) dependent on both the pressure and the temperature of the gas. 
E) a constant that is independent of pressure,volume or temperature.

Question 15

The volume of a carbon dioxide bubble rising in a glass of beer is observed to nearly double as the bubble rises from the bottom to the top of the glass.Why,according to our textbook,does the volume nearly double?

Accepted Answer

A) The temperature at the bottom is cooler than it is at the top. 
B) The amount of carbon dioxide in the bubble increases. 
C) The fluid pressure of the beer is greater at the bottom of the glass than at the top. 
D) The pressure inside the bubble decreases as it rises. 
E) The shape of the glass determines the net force exerted on the bubble.

Exam 14: The Ideal Gas Law and Kinetic Theory