The forces of attraction between the ions are significant and, therefore, make them move, that is required to melt t = 800 C, a boiling point of 1413 C. If the crystal of salt into the water, it dissolves quickly. Na + ions and Cl-easily disconnected to each other. In doing so, they help water molecules (dipoles), bearing on its surface positive and negative charges. Water dipoles orient themselves around the ions Na + and Cl-on the surface of the crystals by their charges and destroy the ionic bonds in the crystal.
The ions Na + and Cl-into the solution, surrounded by water dipoles, that is, become hydrated ions. Getting rid of the water molecules to ions Na + and Cl-can only be just in the process crystallization, but it's hard. Everyone says that if you throw in a hot frying pan salt crystals, then they crack and break, it's boiling water in them (it forms crystals in the cavity) breaks the crystals. Prove that composition consists of sodium chloride ions Na + and Cl-by using experiments: Na + ions in flames are painted yellow Cl-ions react with silver ions Ag + (r-ra silver nitrate AgNO3 ) white caseous precipitate. Cl-+ Ag + = AgCl ions Na + and Cl-differ little in their size, so a cubic crystal shape. However, the shape of a crystal can be different. It depends on the crystallization conditions. The form may be in the form of hexagonal plates, if the solution is evaporated in the cold – 15 C.