Water as a solovent

Ionic crystals, such as sodium chloride (NaCl), are held together by the attraction between positive ions and negative ions. (e.g. Na+ and Cl-). When NaCl dissolves in water, Cl- ions are attracted to the slightly positive hydrogen atoms in the polar water molecule. Similarly Na+ ions are attracted by the slightly negative oxygen atom in the polar water molecule.

Na+ and Cl- ions are completely surronded by water molecules as the salt dissolves. Water is a good solvent of ionic, charged and polar chemicals. This is due to the attraction between particles in the chamicals and the polar water molecules. Non-polar substances, such as lipids, do not disslove in water.