Talk:Effusion

!!!! There's an error in the page, or in Wikipedia !!!! --208.67.99.244 (talk) 20:05, 21 February 2009 (UTC)[reply]

The example comparing the rates of deflation of a balloon filled oxygen and hydrogen seems to be misleading. A oxygen molecule is several times larger than a hydrogen molecule, and in this case with the pores in the membrane being on the molecular scale, would be an equally if not more important factor. Mentioning the use of effusion for enrichment of nuclear isotopes might provide a better example.

The implication that two gases having the same temperature would have the same kinetic energy is false. Temperature is a measure of the change in entropy vs. the change in energy; two gases at the same temperature do NOT necessarily have the same amount of energy! To put it another way, recall the concept of specific heat. Specific heat is the amount of energy required to raise a given amount of a substance by 1 degree C. If one gas has a higher specific heat than another, it can end up containing more energy than the gas with the lower specific heat by the time it's raised to the same temperature. Because of this, I edited the text to contain "(and having the same specific heat)" to the sentence about energy and average velocity.

See also....