Kinetic Theory: Master Thermal Physics with Interactive Quizzes

Question 1

The mean free path of a molecule can be defined as:

Accepted Answer

The average distance it travels between collisions

Answer

The total distance it travels before colliding

Answer

The shortest distance between molecules

Answer

The average time it takes between collisions

Question 2

Which of the following is NOT a fundamental assumption of the kinetic theory of gases?

Accepted Answer

Gas molecules interact with each other through attractive and repulsive forces.

Answer

Gas molecules are in constant, random motion.

Answer

Collisions between gas molecules are perfectly elastic.

Answer

Gas molecules are point masses with no internal structure.

Question 3

According to the kinetic theory of gases, the root-mean-square speed of gas molecules is directly proportional to:

Accepted Answer

The absolute temperature of the gas.

Answer

The volume of the container.

Answer

The number of moles of gas in the container.

Answer

The pressure of the gas.

Question 4

How does the average kinetic energy of a gas molecule change if the pressure is increased at constant temperature?

Accepted Answer

Remains the same

Answer

Increases

Answer

Decreases

Answer

Halves

Question 5

What is the definition of the molar specific heat capacity of a gas?

Accepted Answer

The amount of heat required to increase the temperature of 1 mole of the gas by 1 degree Celsius

Answer

The amount of heat required to increase the temperature of 1 gram of the gas by 1 degree Celsius

Answer

The amount of heat required to increase the temperature of 1 kilogram of the gas by 1 degree Celsius

Answer

The amount of heat required to increase the temperature of 1 liter of the gas by 1 degree Celsius

Question 6

What happens to the temperature of a gas sample undergoing an adiabatic expansion?

Accepted Answer

Decreases

Answer

Increases

Answer

Remains constant

Answer

Cannot be determined without additional information

Question 7

What is the key difference between a real gas and an ideal gas?

Accepted Answer

Real gases have volume and attractive forces, while ideal gases do not

Answer

Ideal gases have volume and attractive forces, while real gases do not

Answer

Real gases have attractive forces but no volume, while ideal gases have volume but no attractive forces

Answer

There is no difference between real gases and ideal gases

Question 8

How is the average kinetic energy of gas molecules linked to gas temperature?

Accepted Answer

Average kinetic energy is directly proportional to temperature.

Answer

Average kinetic energy is inversely proportional to temperature.

Answer

Average kinetic energy remains unaffected by temperature.

Answer

Average kinetic energy varies with the square root of temperature.

Question 9

What term denotes the most probable speed of molecules in a gas at a specific temperature?

Accepted Answer

Most probable speed

Answer

Average speed

Answer

Root mean square speed

Answer

Median speed

Question 10

Which process increases the kinetic energy of gas molecules?

Accepted Answer

Heating

Answer

Cooling

Answer

Compressing

Answer

Expanding

Question 11

The Maxwell-Boltzmann distribution illustrates the distribution of:

Accepted Answer

Molecular speeds

Answer

Molecular energies

Answer

Molecular positions

Answer

Molecular charges

Question 12

The formula for kinetic energy (KE) is:

Accepted Answer

KE = 1/2 mv^2

Answer

KE = mv

Answer

KE = p^2/2m

Answer

KE = mgh

Question 13

The ideal gas law can be expressed as:

Accepted Answer

PV = nRT

Answer

PV = n/RT

Answer

V/P = nRT

Answer

n/V = RT

Question 14

Which of the following is NOT a property of a gas in accordance with the Kinetic Theory?

Accepted Answer

All gas particles have the same energy.

Answer

Gas particles are in constant random motion.

Answer

Collisions between gas particles are perfectly elastic.

Answer

Gas particles have negligible volume.

Question 15

How do you increase the average kinetic energy of molecules in a gas?

Accepted Answer

Increase the temperature.

Answer

Increase the pressure.

Answer

Decrease the volume.

Answer

Remove molecules.

Question 16

What is the relationship between the root mean square speed of gas molecules and the temperature of the gas?

Accepted Answer

The root mean square speed is proportional to the square root of the temperature.

Answer

The root mean square speed is independent of the temperature.

Answer

The root mean square speed is inversely proportional to the temperature.

Question 17

A gas is enclosed in a piston-equipped container. The volume of the gas is decreased while the temperature remains constant. What happens to the pressure exerted by the gas?

Accepted Answer

It increases.

Answer

It remains the same.

Answer

It becomes zero.

Answer

It decreases.

Question 18

Which of the following statements is NOT a fundamental assumption of the Kinetic Theory of gases?

Accepted Answer

Gas molecules have a fixed volume.

Answer

Gas molecules are in constant random motion.

Answer

The average kinetic energy of gas molecules is proportional to the absolute temperature.

Answer

Collisions between gas molecules are perfectly elastic.

Question 19

A container holds a fixed amount of gas at constant pressure. If the temperature of the gas is increased, what happens to the average speed of the gas molecules?

Accepted Answer

The average speed increases.

Answer

The average speed decreases.

Answer

The average speed fluctuates randomly.

Answer

The average speed remains constant.

Question 20

Two gases, A and B, are at the same temperature. Gas A has a molar mass twice that of gas B. What can be said about the average kinetic energy of the molecules of each gas?

Accepted Answer

The average kinetic energies are the same.

Answer

The average kinetic energies are related to the molar masses.

Answer

Gas B has twice the average kinetic energy of gas A.

Answer

Gas A has twice the average kinetic energy of gas B.

Question 21

A gas is compressed at a constant temperature. According to the Kinetic Theory, what happens to the pressure of the gas?

Accepted Answer

The pressure increases.

Answer

The pressure decreases.

Answer

The pressure remains constant.

Question 22

The Maxwell-Boltzmann distribution describes the distribution of speeds of gas molecules at a given temperature. What does the peak of the curve represent?

Accepted Answer

The most probable speed of the gas molecules.

Answer

The average speed of the gas molecules.

Answer

The maximum speed of any gas molecule.

Answer

The root-mean-square speed of the gas molecules.

Question 23

Two identical containers hold different gases at the same temperature. Container A contains helium and container B contains nitrogen. Which gas has a higher average speed?

Accepted Answer

Helium

Answer

It's impossible to determine without knowing the pressure.

Answer

Nitrogen

Answer

Both gases have the same average speed.

Question 24

The Kinetic Theory helps explain the phenomenon of diffusion. How does the Kinetic Theory explain diffusion?

Accepted Answer

Gas molecules are in constant random motion, causing them to spread out and mix with other gases.

Answer

Gas molecules have a strong attraction to each other, causing them to diffuse.

Answer

Diffusion is caused by external forces acting on the gas molecules.

Question 25

A small, lightweight object is placed on a surface and a stream of air is directed at it. Why does the object move away from the air stream?

Accepted Answer

The air molecules collide with the object, transferring momentum and causing it to move.

Answer

The air pressure is lower behind the object, pushing it away.

Answer

The air molecules are attracted to the object, pulling it away.

Question 26

A balloon filled with air is heated. Which of the following best explains why the balloon expands?

Accepted Answer

The increased temperature causes the air molecules to move faster and collide with the balloon walls more frequently and with greater force.

Answer

The heat makes the balloon material expand.

Question 27

A container holds a mixture of two gases, oxygen and nitrogen. Which of the following statements is TRUE regarding the average kinetic energy of the molecules?

Accepted Answer

Both oxygen and nitrogen molecules have the same average kinetic energy at a given temperature.

Answer

Nitrogen molecules have higher average kinetic energy than oxygen molecules.

Answer

Oxygen molecules have higher average kinetic energy than nitrogen molecules.