The mass of an oxygen molecule is 16 times that of a hydrogen molecule. At room temperature, the ratio of the rms speed of an oxygen molecule to that of a hydrogen molecule is:
A) 16
B) 4
C) 1
D) 1/4
E) 1/16

Question

Quizplus · Accepted Answer

The root mean square (rms) speed of a molecule in a gas is inversely proportional to the square root of its mass. Since the mass of an oxygen molecule is 16 times that of a hydrogen molecule, the ratio of their rms speeds is the square root of 1/16, which is 1/4.

The Mass of an Oxygen Molecule Is 16 Times That