液體蒸發平衡及其穩定性討論

Discussion of Equilibrium and Its Stability of Liquid Evaporating

張世民(Shi-Min Zhang)

《化學》 59卷4期 (2001/12) Pp. 489-494

https://doi.org/10.6623/chem.2001056

摘要

對於常溫和常外壓條件下純液體的蒸發，不論氣泡內有無空氣，氣泡內液體蒸氣和氣泡外液體的相平衡總是一種穩定平衡，然而，力學平衡則不然。如果氣泡內沒有空氣，則當氣泡內液體蒸氣壓小於或等於外壓時，氣泡和液體不能達成力學平衡；當氣泡內液體蒸氣壓大於外壓時，氣泡和液體也只能達成一非穩定的力學平衡。如果氣泡內有空氣，則當氣泡內液體蒸氣壓小於或等於外壓時，氣泡和液體能達成一穩定的力學平衡；當氣泡內液體蒸氣壓大於外壓時，氣泡和液體可達成一非穩定的力學平衡，或不能達成力學平衡。

關鍵字

液體蒸發 ； 平衡 ； 穩定性

並列摘要

For the evaporation of the pure liquid under the condition of constant temperature and constant external pressure, the phase equilibrium of the liquid vapor in a bubble and the liquid outside the bubble is always a kind of stable equilibrium whether there is air or not in the bubble. Under the condition of the above phase equilibrium being met, if there is no air in a bubble, the bubble and liquid can not coexist at mechanical equilibrium being met, if there is no air in a bubble , the bubble and liquid can not coexist at mechanical equilibrium when the vapor pressure of the liquid in a bubble is less than or equal to the external pressure; the bubble and liquid can coexist at an unstable unstable equilibrium of mechanics when the vapor pressure of the liquid in the bubble is greater than the external pressure. If there is air in a bubble, the bubble and liquid can coexist at a stable equilibrium of mechanics when the vapor pressure of the liquid in the bubble is greater than the external pressure and less than a certain pressure; the bubble ad liquid can not coexist at any mechanical equilibrium when the vapor pressure of the liquid in the bubble is greater than this pressure, this is also the reason of liquid boiling.

並列關鍵字

liquid evaporating ； equilibrium ； stability