NaOH/KOH 可同時吸h2o/co2

Theoretically yes.

NaOH and KOH react with CO2 to form Na2CO3 or K2CO3. They are good in removing CO3 from a mixture of gases.

NaOH and KOH are deliquescent substances too. However we seldom use it to remove moisture from air/gases as
1) the hydroxides usually exist in granular form which is not that efficient in absorbing water, and
2) after absorbing water, they quickly turn themselves into a liquid which is hard to handle and further weakens their water absorption ability as the liquid covers the granule surface.

吸h2o/co2 係不同的慨念的。
吸H2O的原因是NaOH和KOH都有潮解性，係物理變化，最後生成NaOH和KOH水溶液。
吸CO2的原因是CO2為酸性氧化物，會發生中和反應。生成Na2CO3/K2CO3水溶液，為化學變化。

吸唔到H2O wor
如果你d H2O 係liquid, 倒落NaOH/KOH 係溶到ge
至於CO2係好似吸到ge.... 冇記錯ge話...

2007-06-20 10:53:03 補充：
check左la我.... 係吸到CO2架! 好多bio ge實驗都用KOH pallet 吸CO2, 例如photosynthesis, respiration ge實驗

they can't~ H2SO4 can take H2O away. And lime water can check CO2