Gases: Properties, Laws, and Applications in Mechanical Engineering

Question 1

A defining characteristic of real gases is that:

Accepted Answer

They deviate from ideal gas behavior at high pressures and low temperatures

Answer

They obey the ideal gas law under all conditions

Answer

They have a negligible volume compared to the volume of the container

Answer

They have a constant molar volume

Question 2

To calculate the molar mass of an ideal gas, which data are required?

Accepted Answer

The ideal gas law and the gas density

Answer

The Boyle's law and the Charles's law

Answer

The partial pressure and the total pressure

Answer

The temperature and the volume

Question 3

According to the kinetic molecular theory, gas molecules are characterized by:

Accepted Answer

Constant random motion

Answer

Fixed volume

Answer

Strong intermolecular forces

Answer

Negligible kinetic energy

Question 4

The root-mean-square speed of gas molecules is directly proportional to what quantity?

Accepted Answer

The square root of the temperature

Answer

The inverse square root of the temperature

Answer

The pressure

Answer

The volume

Question 5

Boyle's law states that the pressure of an ideal gas is inversely proportional to its volume at constant temperature. Which of the following options correctly describes this relationship?

Accepted Answer

Inversely proportional

Answer

Directly proportional

Answer

Exponentially proportional

Question 6

Which of the following is NOT a gas law?

Accepted Answer

Ohm's law

Answer

Boyle's law

Answer

Charles's law

Answer

Dalton's law

Question 7

Charles's law relates the volume of a gas to its:

Accepted Answer

Temperature

Answer

Pressure

Answer

Number of moles

Answer

Density

Question 8

The ideal gas law combines Boyle's and Charles's laws to describe the behavior of gases under various conditions. Which of the following is the mathematical form of the ideal gas law?

Accepted Answer

PV = nRT

Answer

P/T = nV

Answer

V/T = nP

Answer

PV/T = nR

Question 9

Which of the following gases has the highest density at room temperature?

Accepted Answer

Carbon dioxide

Answer

Helium

Answer

Nitrogen

Answer

Oxygen

Question 10

A piston contains a sample of nitrogen gas. The piston is slowly compressed, causing the pressure of the gas to increase. What happens to the kinetic energy of the nitrogen molecules?

Accepted Answer

It increases

Answer

It decreases

Answer

It remains the same

Answer

It fluctuates

Question 11

Which of the following applications of gases is NOT related to mechanical engineering?

Accepted Answer

Food preservation

Answer

Pneumatic systems

Answer

Turbomachinery

Answer

Refrigeration

Question 12

Which statement about Boyle's law is correct?

Accepted Answer

At constant temperature, the volume of an ideal gas is inversely proportional to its pressure.

Answer

At constant temperature, the pressure of an ideal gas is directly proportional to its volume.

Question 13

Charles's law describes the relationship between the volume and temperature of an ideal gas at constant pressure. Which statement accurately reflects Charles's law?

Accepted Answer

The volume of an ideal gas is directly proportional to its absolute temperature.

Answer

The pressure of an ideal gas is directly proportional to its absolute temperature.

Answer

The volume of an ideal gas is inversely proportional to its absolute temperature.

Question 14

The ideal gas law combines the principles of which three gas laws?

Accepted Answer

Boyle's law, Charles's law, and Avogadro's law

Answer

Charles's law, Graham's law, and Avogadro's law

Answer

Boyle's law, Graham's law, and Avogadro's law

Answer

Boyle's law, Charles's law, and Gay-Lussac's law

Question 15

Among the following gases, which has the highest molar mass?

Accepted Answer

Carbon dioxide (CO2)

Answer

Helium (He)

Answer

Nitrogen (N2)

Answer

Oxygen (O2)

Question 16

The root-mean-square velocity of gas molecules is related to temperature. Which statement accurately describes this relationship?

Accepted Answer

The root-mean-square velocity of gas molecules is proportional to the square root of the absolute temperature.

Answer

The root-mean-square velocity of gas molecules is proportional to the absolute temperature.

Answer

The root-mean-square velocity of gas molecules is inversely proportional to the absolute temperature.

Question 17

The density of a gas refers to its mass per unit volume. Which of the following units correctly represents the density of a gas?

Accepted Answer

Grams per liter (g/L)

Answer

Kelvins per liter (K/L)

Answer

Atmospheres per liter (atm/L)

Answer

Liters per gram (L/g)

Question 18

According to Boyle's law, if the temperature of a gas remains constant, what happens to the volume of the gas if the pressure is increased?

Accepted Answer

Decreases

Answer

Remains the same

Answer

Cannot be determined

Answer

Increases

Question 19

At a constant volume, which gas sample will have the highest average kinetic energy?

Accepted Answer

Gas with the highest temperature

Answer

Gas with the lowest temperature

Answer

Gas with the lowest pressure

Answer

Gas with the highest pressure

Question 20

Which of the following gases has the greatest molar mass?

Accepted Answer

Xenon

Answer

Oxygen

Answer

Nitrogen

Answer

Hydrogen

Question 21

According to Charles's law, if the pressure of a gas remains constant, what happens to the volume of the gas if the temperature is decreased?

Accepted Answer

Decreases

Answer

Increases

Answer

Cannot be determined

Answer

Remains the same

Question 22

Which of the following is NOT a characteristic of an ideal gas?

Accepted Answer

Molecules have finite volume

Answer

Collisions between molecules are perfectly elastic

Answer

Molecules move randomly

Answer

Average kinetic energy is proportional to absolute temperature

Question 23

A gas sample has a volume of 15 L at 2 atm. If the temperature remains constant, what will be the new pressure if the volume is reduced to 5 L?

Accepted Answer

6 atm

Answer

Cannot be determined

Answer

12 atm

Answer

3 atm

Question 24

Which factor affects the partial pressure of a gas in a mixture?

Accepted Answer

Mole fraction

Answer

Volume

Answer

Kinetic energy

Answer

Temperature