Types of Solutes

1. Types of Solutes Electrolytes and Non-Electrolytes

2. Solutes Solutes that dissolve to form solutions that conduct electricity are called electrolytes. Solutes that dissolve to form solutions that don�t conduct electricity are called non-electrolytes.

3. Electricity Electricity is the flow of charged particles. In order for a substance to conduct electricity two requirements must be met: There must be charged particles present and The charged particles must be able to move

4. Does pure water conduct electricity? Pure water is made up of water molecules that do not carry a charge. Since water does not have charged particles, water is a non-conductor.

5. Electrolytes When some solutes dissolve in water they allow an electric current to flow through the water and the solution conducts electricity. These solutes are called electrolytes.

6. Non-Electrolytes When other solutes dissolve in water they do not allow an electric current to flow through the water and the solution does not conduct electricity. These solutes are called non-electrolytes.

7. Why Do Solutes Behave Differently? The Theory of Ionization explains this behavior. It states that some solutes dissolve to form charged particles in solution while others dissolve to form neutral molecules in solution.

8. Electrolytes form ions in solution Electrolytes like salt (sodium chloride) dissolve to form ions: NaCl (s) ? Na+ (aq) + Cl- (aq) Since the solution contains charged particles and the charged particles are able to move, solutions of electrolytes conduct electricity.

9. Non-electrolytes form molecules in solution Non-electrolytes like sugar dissolve to form molecules in solution. C6H12O6 (s) ? C6H12O6 (aq) Since there are no charged particles present, solutions of non-electrolytes are not able to conduct electricity.

10. Sugar dissolves in water

11. Electrolytes & Colligative Properties In the last chapter we learned that adding solute to a solvent had three effects: It lowered the vapor pressure of the solvent It lowered the freezing point of the solution It raised the boiling point of the solution

12. Colligative Properties and solute particles In the last section we also learned that the colligative properties were dependent on the concentration of the solute particles and NOT on what the solute particles are.

13. An apparent contradiction!

14. More Proof of ionization

15. Another Look

16. Conclusion The fact that electrolytes have a greater effect on freezing point demonstrates two things: Electrolytes break up into ions when they dissolve. Colligative properties are NOT dependent on what the solute particles are (+ and � ions have the same effect).

17. Comparison of Electrolytes and Non-electrolytes

18. Two Types of Electrolytes All electrolytes break up to form charged particles in solution. However, not all electrolytes have the same properties. This has led chemists to define: Strong electrolytes Weak electrolytes

19. Strong Electrolytes

20. Weak Electrolytes

21. Comparison of Strong and Weak Electrolytes

22. Rank the following Rank the following solutions from highest freezing point to lowest: 1 M NaCl (aq) 1 M CaCl2 (aq) Pure water 1 M C6H12O6 (aq) 1 M HC2H3O2 (aq)

23. Rank the following Rank the following solutions from highest freezing point to lowest: Pure water C6H12O6 HC2H3O2 NaCl CaCl2