Question

why water contains so many mineral salts dissolved in it

Answer 1

Absolutely pure water contains only the molecule H2O. It does not exist in nature, and the absence of mineralsmakes it unsuitable for drinking. Natural water contains dissolvedsubstances, mainly inorganic salts(minerals) originating from the geological layers through which thewater has passed.

Answer 2

Water can dissolve salt because the positive part of water molecules attracts the negative chloride ions and the negative part of watermolecules attracts the positive sodium ions. The amount of a substance that can dissolvein a liquid (at a particular temperature) is called the solubility of the substance.