Question

when you buy washing soda from the market you will get it in powder form because

Answer 1

Washing soda or Na₂CO₃ have some specific physical and chemical attributes which promotes the powder form of it rather than crystal or liquid form while transporting it or selling it.

1) As washing soda is highly hygroscopic, it's aqueous solution is easy to make, thus selling it as powder form takes comparatively less space than aqueous form.

2) The crystals are made powder because powder is more homogeneous and can be quantify easily than crystals.