5.1.3 - Properties of Ionic Compounds
5.1 - Ionic Bonding
Some general points can be made about ionic compounds:
- The smallest unit of an ionic compound is a formula
unit. The mass of this formula unit is called the formula
- The formula unit of sodium chloride is NaCl. It has a formula mass
is 58.44 amu/formula unit.
- The formula unit of sodium chloride is MgCl2. It has a formula
mass is 95.21 amu/formula unit.
- The strong attractions between the cations and the anions in ionic solids
are responsible for their high melting points. For ionic compounds, melting
points typically range from 300oC to 1000oC.
- Ionic compounds are soluble in water.
- In aqueous
solution, an ionic compound dissociates
into its ions.
- This means that when NaCl is dissolved in water, the solution contains
Na+ ions and Cl- ions.
- The dissociated ions in aqueous solution gives the solution the ability
to conduct electricity. Therefore, ionic compounds dissolved in water makes
Ionic Bond ..p124