Crystalline Nature: NACl & NA2CO3.10H2O Explained

[anigeo]

is it necessary that all crystalline solids are hydrated or hygroscopic.
could anyone explain me the case of NACl and NA₂CO₃.10H₂O?

 

[jedishrfu]

could you be a little more description as to what you're investigating you know some context for your question?

 

[Borek]

http://en.wikipedia.org/wiki/File:Quartz,_Tibet.jpg

No crystalline water, not hygroscopic.

Does it answer your question?

 

[anigeo]

is it so that Na₂CO₃.10H₂O crystalline and Na₂CO₃ not?if not what it is.

 

[Borek]

is it so that Na₂CO₃.10H₂O crystalline and Na₂CO₃ not?if not what it is.

Please elaborate, I don't understand your question.

Many substances will contain crystalline water when crystallized from water solutions, and it can be difficult to prepare their anhydrous crystals. In such cases it may mean anhydrous crystals will be very hygroscopic. It doesn't mean every crystal of every substance contains crystalline water and is hygroscopic, as is clearly shown by the quartz example.

 

[AbedeuS]

Some chemicals just tend to have a high affinity to water. So in the case of your Na₂CO₃ it may well have been crystallized from water or in a wet environment and its affinity for water dictates that the lowest energy pathway to crystallization just so happens to include any nearby water molecules.

You could equally crystallize them in anhydrous conditions but the resulting anhydrous, crystalline, substance is still the same chemical and as such still has its affinity for water which makes it a hygroscopic material.

 

[anigeo]

Please elaborate, I don't understand your question.

Many substances will contain crystalline water when crystallized from water solutions, and it can be difficult to prepare their anhydrous crystals. In such cases it may mean anhydrous crystals will be very hygroscopic. It doesn't mean every crystal of every substance contains crystalline water and is hygroscopic, as is clearly shown by the quartz example.

thanks i just thought that anhydrous crystals can never be produced.