RMS Speed of Gas Molecules NEET Questions

Physics - Kinetic Theory of Gases

RMS Speed of Gas Molecules MCQ Questions


13.
At absolute zero (T = 0 K), the RMS speed of gas molecules is:
A.
Zero — since vᵣₘₛ = √(3RT/M) → vᵣₘₛ = 0 when T = 0 (classically)
B.
Undefined (molecules don't exist at absolute zero)
C.
A large finite value (molecules are still moving due to zero-point energy)
D.
Negative (molecules move in reverse direction at T = 0)
😑 View Answer Rough Work Error
ANSWER :
A. Zero — since vᵣₘₛ = √(3RT/M) → vᵣₘₛ = 0 when T = 0 (classically)
14.
As temperature of a gas increases at constant pressure, the Maxwell-Boltzmann distribution curve:
A.
Becomes taller and narrower, shifting to the right
B.
Remains unchanged in shape but shifts to the right only
C.
Flattens and shifts to the right (higher speed region) — the peak becomes lower and broader, indicating more molecules at higher speeds
D.
Becomes taller and narrower, shifting to the left
😑 View Answer Rough Work Error
ANSWER :
C. Flattens and shifts to the right (higher speed region) — the peak becomes lower and broader, indicating more molecules at higher speeds
15.
The RMS speed of gas molecules is inversely proportional to which power of molar mass?
A.
vᵣₘₛ ∝ M^(−1/2) (inversely proportional to the square root of molar mass)
B.
vᵣₘₛ ∝ M^(−2)
C.
vᵣₘₛ ∝ M^(+1/2)
D.
vᵣₘₛ ∝ M^(−1)
😑 View Answer Rough Work Error
ANSWER :
A. vᵣₘₛ ∝ M^(−1/2) (inversely proportional to the square root of molar mass)
16.
At the same temperature, the RMS speed of hydrogen gas (H₂) molecules compared to oxygen gas (O₂) molecules is:
A.
16 times greater
B.
8 times greater
C.
2 times greater
D.
4 times greater [vH₂/vO₂ = √(MO₂/MH₂) = √(32/2) = √16 = 4]
😑 View Answer Rough Work Error
ANSWER :
D. 4 times greater [vH₂/vO₂ = √(MO₂/MH₂) = √(32/2) = √16 = 4]
17.
At the same temperature, which gas has the highest RMS speed?
A.
Oxygen gas (O₂, M = 32 g/mol)
B.
Carbon dioxide gas (CO₂, M = 44 g/mol)
C.
Nitrogen gas (N₂, M = 28 g/mol)
D.
Hydrogen gas (H₂, M = 2 g/mol) — the lightest gas has the highest RMS speed at any given temperature
😑 View Answer Rough Work Error
ANSWER :
D. Hydrogen gas (H₂, M = 2 g/mol) — the lightest gas has the highest RMS speed at any given temperature
18.
Molar mass is expressed in kg/mol in the RMS speed formula. The molar mass of nitrogen (N₂) is:
A.
0.028 kg/mol (= 28 g/mol = 28 × 10⁻³ kg/mol)
B.
28 kg/mol
C.
0.28 kg/mol
D.
2.8 × 10⁻³ kg/mol
😑 View Answer Rough Work Error
ANSWER :
A. 0.028 kg/mol (= 28 g/mol = 28 × 10⁻³ kg/mol)