Q. In an ideal gas, the mean free path is defined as the average distance a molecule travels between collisions. Which factor does NOT affect the mean free path?
A.Temperature of the gas.
B.Density of the gas.
C.Size of the gas molecules.
D.Color of the gas molecules.
Solution
The mean free path is affected by temperature, density, and size of the molecules, but not by the color of the gas molecules.
Q. In an ideal gas, the root mean square speed of the gas molecules is given by which of the following formulas?
A.v_rms = √(3RT/M)
B.v_rms = √(RT/M)
C.v_rms = √(2RT/M)
D.v_rms = √(R/M)
Solution
The root mean square speed of gas molecules is given by the formula v_rms = √(3RT/M), where R is the gas constant, T is the temperature, and M is the molar mass.
Q. In the kinetic theory of gases, what does the term 'ideal gas' refer to?
A.A gas that obeys the ideal gas law at all conditions.
B.A gas with no intermolecular forces.
C.A gas that has a fixed volume.
D.A gas that can be liquefied easily.
Solution
An ideal gas is defined as a gas that has no intermolecular forces and occupies no volume, allowing it to perfectly obey the ideal gas law under all conditions.
Correct Answer: B — A gas with no intermolecular forces.
Q. In the kinetic theory of gases, which of the following quantities is directly proportional to the square of the speed of gas molecules?
A.Pressure
B.Volume
C.Temperature
D.Density
Solution
According to the kinetic theory, pressure is directly proportional to the average kinetic energy of the gas molecules, which is proportional to the square of their speed.
Q. In which condition does the ideal gas law fail?
A.High temperature and low pressure
B.Low temperature and high pressure
C.High volume
D.Low volume
Solution
The ideal gas law fails under low temperature and high pressure conditions, where gas particles are close together and intermolecular forces become significant.
Correct Answer: B — Low temperature and high pressure
Q. The concept of an ideal gas is based on which of the following assumptions?
A.Molecules have no volume
B.Molecules do not attract or repel each other
C.Collisions are perfectly elastic
D.All of the above
Solution
The concept of an ideal gas is based on the assumptions that molecules have no volume, do not attract or repel each other, and that collisions are perfectly elastic.
Q. What happens to the average kinetic energy of gas molecules if the temperature is increased?
A.It decreases.
B.It remains constant.
C.It increases.
D.It becomes zero.
Solution
The average kinetic energy of gas molecules is directly proportional to the absolute temperature. Therefore, increasing the temperature increases the average kinetic energy.
Q. What is the average kinetic energy of one mole of an ideal gas at temperature T?
A.(3/2)RT
B.(5/2)RT
C.(1/2)RT
D.(2/3)RT
Solution
The average kinetic energy of one mole of an ideal gas is given by the formula KE = (3/2)RT, where R is the gas constant and T is the temperature in Kelvin.
