solubility

• why does salt dissolve in water?

  sodium chloride is ionic and water also has a charge

  this means they are both polar
• rules for something to dissolve

  bonds in the substance have to break

  bonds in the solvent have to break

  new bonds have to form between substance and solvent
• why might some things not dissolve?

  will only dissolve if the strength of the new bonds formed is the same of greater than the strength of the bonds broken
• why might some ionic substances not dissolve water?

  this is because the bonding between their ions are too strong
• why is aluminium oxide insoluble?

  bonds between its ions are are stronger than the bonds it will form with water

  aluminium ion has a high charge density
• why does oil not dissolve in water?

  does not dissolve because the attraction between oil and water is not strong enough to disrupt the hydrogen bonds in the water

  bonds formed are weaker than the hydrogen bonds already present in the water