Question 1

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 2

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 3

A five-liter tank contains 2.00 moles of oxygen gas, O2, at 40 °C. What pressure is exerted on the sides of the tank by the oxygen molecules?

Accepted Answer

A) 83.3 Pa 
B) 4.01 × 103 Pa 
C) 1.33 × 105 Pa 
D) 4.01 × 105 Pa 
E) 1.04 × 106 Pa

Question 4

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 5

A sample of neon gas at 20 °C is confined to a cylinder with a movable piston. The gas is then heated until its pressure is doubled. What is the final temperature of the gas?

Accepted Answer

A) 10 °C 
B) 40 °C 
C) 313 °C 
D) 586 °C 
E) This cannot be found since the final and initial volumes are unknown.

Question 6

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 7

Two pure samples of atoms, labeled A and B, contain titanium (Ti) atoms and carbon (C) atoms, respectively. Each sample contains the same number of atoms. What is the ratio of the mass of sample B to that of sample A, mB/mA? Note the following atomic masses: C = 12 u; Ti = 48 u.

Accepted Answer

A) 1.0 
B) 0.25 
C) 2.0 
D) 0.50 
E) 4.0

Question 8

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 9

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 10

Two moles of a monatomic gas with an rms speed of 294 m/s are contained in a tank that has a volume of 0.12 m3. If each gas particle has a mass of 8.220 × 10-26 kg, what is the absolute pressure of the gas?

Accepted Answer

A) 2.1 × 105 Pa 
B) 1.1 × 104 Pa 
C) 4.8 × 104 Pa 
D) 2.4 × 104 Pa 
E) 3.0 × 104 Pa

Question 11

An ideal gas is contained in a vessel with a moveable piston. Initially, the gas has a volume of 0.024 m3, an absolute pressure of 1.8 atm, and a temperature of 35.0 °C. The pressure is 0.90 atm when the volume of the container is decreased to 0.012 m3. What is the final temperature of the gas?

Accepted Answer

A) 77 K 
B) 85 K 
C) 170 K 
D) 154 K 
E) 282 K

Question 12

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 13

Calculate the rms speed of the carbon dioxide molecules in the air if the temperature is 15.0 °C. Note: The mass of the carbon dioxide molecule is 44.01 u.

Accepted Answer

A) 316 m/s 
B) 469 m/s 
C) 378 m/s 
D) 404 m/s 
E) 511 m/s

Question 14

What is the approximate mass of an oxygen molecule, O2, if the atomic mass of oxygen is 15.9994 u?

Accepted Answer

A) 2.657 × 10-26 kg 
B) 5.313 × 10-26 kg 
C) 3.200 × 10-25 kg 
D) 6.400 × 10-25 kg 
E) 1.927 × 10-23 kg

Question 15

What is the internal energy of 1.75 kg of helium (atomic mass = 4.00260 u) with a temperature of 100 °C?

Accepted Answer

A) 4.65 × 103 J 
B) 5.44 × 105 J 
C) 2.03 × 106 J 
D) 8.16 × 106 J 
E) 1.22 × 107 J

Question 16

A gas molecule with a molecular mass of 32.0 u has a speed of 325 m/s. What is the temperature of the gas molecule?

Accepted Answer

A) 72.0 K 
B) 136 K 
C) 305 K 
D) 459 K 
E) A temperature cannot be assigned to a single molecule.

Question 17

At what temperature would one mole of molecular nitrogen (N2) have 7.0 × 103 J of translational kinetic energy? Note: the atomic mass of N is 14 u.

Accepted Answer

A) 130 °C 
B) 290 °C 
C) 480 °C 
D) 560 °C 
E) 720 °C

Question 18

A lower tank contains water while an upper tank contains air with a negligible concentration of water vapor. A tube with a circular cross section and radius 0.050 m is inserted between the two tanks. The length of the tube is 0.25 m. The diffusion coefficient of water vapor through air is 2.4 × 10-5 m2/s. The concentration of water vapor just above the surface of the water is 1.7 × 10-2 kg/m3. If the water vapor is removed from the upper tank so that the concentration there remains nearly zero, what mass of water vapor diffuses through the tube each hour?

Accepted Answer

A) 4.6 × 10-5 kg 
B) 2.0 × 10-6 kg 
C) 7.1 × 10-7 kg 
D) 1.3 × 10-8 kg 
E) 8.2 × 10-8 kg

Question 19

Under which of the following conditions would you expect real gases to approach ideal behavior?

Accepted Answer

A) low temperature and low pressure 
B) high temperature and low pressure 
C) low temperature and high pressure 
D) high temperature and high pressure 
E) high temperature and high density

Question 20

Consider two ideal gases, A and B, at the same temperature. The rms speed of the molecules of gas A is twice that of gas B. How does the molecular mass of A compare to that of B?

Accepted Answer

A) The molecular mass of A is twice that of B. 
B) The molecular mass of A is one half that of B. 
C) The molecular mass of A is 1.4 times that of B. 
D) The molecular mass of A is one fourth that of B. 
E) The molecular mass of A is four times that of B.

Exam 14: The Ideal Gas Law and Kinetic Theory

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

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

A five-liter tank contains 2.00 moles of oxygen gas, O₂, at 40 °C. What pressure is exerted on the sides of the tank by the oxygen molecules?

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?

A sample of neon gas at 20 °C is confined to a cylinder with a movable piston. The gas is then heated until its pressure is doubled. What is the final temperature of the gas?

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

Two pure samples of atoms, labeled A and B, contain titanium (Ti) atoms and carbon (C) atoms, respectively. Each sample contains the same number of atoms. What is the ratio of the mass of sample B to that of sample A, m_B/m_A? Note the following atomic masses: C = 12 u; Ti = 48 u.

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?

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?

Two moles of a monatomic gas with an rms speed of 294 m/s are contained in a tank that has a volume of 0.12 m³. If each gas particle has a mass of 8.220 × 10^-26 kg, what is the absolute pressure of the gas?

An ideal gas is contained in a vessel with a moveable piston. Initially, the gas has a volume of 0.024 m³, an absolute pressure of 1.8 atm, and a temperature of 35.0 °C. The pressure is 0.90 atm when the volume of the container is decreased to 0.012 m³. What is the final temperature of the gas?