Question

Is common salt soluble in all types of water?

Answer 1

Most types of water do so; save for the kind that is already saturated with salt.

Explanation:

`NaCl(s) rightleftharpoons Na^+(aq) + Cl^(-)(aq)`

When we write `Na^+(aq)` we means the aquated sodium ion; this results from the chemical dissolution of salt in a water (i.e. aqueous) solvent. Another way of representing this would be: `[Na(OH_2)_6]^+`. The reaction above is a reversible chemical equilibrium, and on standing the salt would deposit as `NaCl` crystals.

It is worthwhile at home to grow macroscopic crystals of salt. Take a saturated solution (a solution that is in equilibrium with undissolved salt), filter it, and add (precisely) 1 tiny crystal of salt. If evaporation is kept to a minimum (by covering the solution), aqueous salt will precipitate only on the 1 salt crystal that you added. I have grown very large crystals (`2.5xx2.5` `cm`) of salt this way.