Conductivity Unit 4 Topic 6

Solutions Solutions are made when a solute is dissolved in a solvent. When the solute dissolves it breaks up into its individual particles which then become surrounded by water molecules.

Ionic solutions Ionic compounds are made up of ions. They dissolve into individual ions in water. This process is called dissociation. Each individual ion has a charge so when dissociated in water they can conduct.

Ionic solutions Ionic solutions are called electrolytes because ions can conduct electricity. The amount of conductivity is directly related to the number of ions in a solution.

Concentration A 1.0 M solution will conduct more than a 0.01 M solution. M = Molarity = moles/Liter Capital M

Concentration If you have a 1.0 M solution of both NaCl and AlCl3, the solution of AlCl3 will have a higher conductivity because it dissociates into more ions. NaCl  Na+1 + Cl-1 (2 ions) AlCl3  Al +3 + 3Cl-1 (4 ions)

Covalent compounds Covalent compounds are made up of individual molecules. They dissolve into their individual molecules. They do not dissociate.

Individual molecules are neutral and do not carry a charge so when dissolved in water they do not conduct. Covalent solutions are called non-electrolytes because they have no charge and cannot conduct.