Question

is the molecule Na₂CO₃.10H₂O wet

Answer 1

yes, because it contains molecules of water which makes it wet

Answer 2

ANSWER
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Yes
You can say so because this water is only physically combined and not chemically.
This combined water is called Water of Crystallisation and can be removed by physical processes such as Heating.

In the same way when water combines with our clothes and by simple physical processes can be removed. If in that case we call "Clothes are wet".

Here we can say that Sodium Carbonate is wet.
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