In a sample of an ideal gas, the average translational kinetic energy of a molecule is 6.0 × 10^-21 J. If the temperature of the gas is increased so that the average translational kinetic energy becomes 9.0 × 10^-21 J, what is the ratio of the new absolute temperature to the original absolute temperature?
Show the answer and explanation
Correct answer
B. 1.5
Principle or equation
The average translational kinetic energy of a molecule in an ideal gas is directly proportional to the absolute temperature: KE_avg = (3/2) k_B T.
Why this answer is correct
Since KE_avg is proportional to T, the ratio of new temperature to original temperature equals the ratio of new average kinetic energy to original average kinetic energy: T_new / T_orig = KE_new / KE_orig = (9.0 × 10^-21) / (6.0 × 10^-21) = 1.5.
Example
If the average kinetic energy increases from 6.0 × 10^-21 J to 9.0 × 10^-21 J, the absolute temperature increases by a factor of 1.5.
This published item includes a stored explanation and passed the platform’s publication workflow. It is independent preparation material, not a claim of an official or recalled examination question.