理想氣體與真實氣體

👨🏻‍🏫 學術台其他 - 科學

Atheist

2010-12-01 3:43 am

In ideal gas, collisions between molecules and the wall of a container are assumed to be perfectly elastic.
In real gas, collsions between molecules and the wall of a container is also perfectly elastic.

I found this answer in at least two years of HKALE physics past paper.
Is that true?
Does anyone know??

更新1:

天同: Is your deduction correct? If the collsions between molecules are not perfectly elastic, why the average kinetic energy must be transferred from the gas molecules to that molecules of container wall?

更新2:

Also, I think we observe no average energy loss in either of them is because they are in the same temperature, otherwise there must be a change in either of them. Wolud you mind to discuss with me?

回答 (2)

天同

2010-12-01 5:33 pm

✔ 最佳答案

This is true.

Just imagine if collisions of gas molecules with the walls of the container wer not perfectly elastic, this imples there would be a transfer of (molecular) kinetic energy from the gas molecules to those of the container wall. As a reuslt, there is a gain in average kinetic energy of molecules in the container wall and a loss in average kinetic energy of molecules of the gas.

If such phenomenon really happened, we would observe macroscopically a fall in temperature of the gas and a rise in temperature of the container when we place a gas and its container on a table. But such phenomenon has never been observed in reality.

Therefore, this can demonstrate that there is indeed no transfer of kinetic energy during collisions of gas molecules with container wall. That means the collisions are perfectly ealstic.

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BENNY LO

2010-12-01 5:05 am

!!!呢條我都有阿sir
佢話係正確的

佢同我講左一個假設:
在一個水樽入面, 有好多空氣
如果real gas 不是 perfectly elastic 的話
即係入面既空氣在某一刻都會不動,
即係無氣壓
咁係不成立的

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收錄日期: 2021-04-29 17:37:34
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