Ionic Substances

• Ionic Substances - Melting Point and Boiling Point


  • ionic substances have high melting and boiling points since ionic compounds have giant ionic crystal lattice structure. The positive and negative ions in the lattice are held together by strong electrostatic forces of attraction, so a lot of energy is required to overcome strong electrostatic forces of attraction
  • the greater the charge of the ions, the stronger the electrostatic forces of attraction, therefore higher melting and boiling point
• Ionic Substances - Electrical Conductivity


  • most ionic compounds are soluble in water but insoluble in organic solvents
  • ionic compounds can conduct electricity in molten and aqueous state
  • When an ionic compound is in solid state, the ions are held together in the giant lattice structure by strong electrostatic forces of attraction. Thus ions cannot move around and cannot act as mobile charge carriers, so cannot conduct electricity
  • When an ionic compound is in molten or aqueous state, the ions move freely and act as mobile charge carriers and thus can conduct electricity
• Ionic Compounds - Malleability


  • ionic compounds are hard but brittle