The velocity of molecules of a gas at temperature 120 K is v. At what temperature will the velocity be 2v?

Options

(a) 120 K
(b) 240 K
(c) 480 K
(d) 1120 K

Correct Answer:

480 K

Explanation:

[ʋ(rms)]² ∝ absolute temperature
[ʋ₂ / ʋ₁]² = T₂ / T₁ ⇒ (2V / V)² = T₂ / 120
.·. T₂ = 120 × 4 = 480 K