[ABA2015]

hi
is there any general rule to distinguish which salts can absorb moisture for example Na2SO4 and Na2CO3 can absorb water, is it explainable by their chemical structure?
thanks for your help

[Arkcon]

Not really no.  Perhaps its explainable with very advanced chemistry that I don't know, but I doubt that's an efficient way to understand the topic.  As a general rule, most soluble salts are at least somewhat hygroscopic.  Sodium salts are very hygroscopic -- so much so that most of them are useless for fireworks, they soon become inert in storage, as a practical example.

[ABA2015]

thanks Arkcon