1. The Solution Process Electrolytes, non-electrolytes

2. © 2009, Prentice-Hall, Inc. Solutions Solutions are defined as homogeneous mixtures of two or more pure substances. The solvent is present in greatest abundance. All other substances are solutes.

3. © 2009, Prentice-Hall, Inc. Dissociation When an ionic substance dissolves in water, the solvent pulls the individual ions from the crystal and solvates them. This process is called dissociation.

4. © 2009, Prentice-Hall, Inc. Electrolytes An electrolyte is a substances that dissociates into ions when dissolved in water. A nonelectrolyte may dissolve in water, but it does not dissociate into ions when it does so.

5. © 2009, Prentice-Hall, Inc. Electrolytes A strong electrolyte dissociates completely when dissolved in water. A weak electrolyte only dissociates partially when dissolved in water.

6. © 2009, Prentice-Hall, Inc. Strong Electrolytes Are… Strong acids Strong bases Soluble Salts

7. Reaction Prediction

8. © 2009, Prentice-Hall, Inc. Metathesis (Exchange) Reactions Metathesis comes from a Greek word that means “to transpose.” AgNO 3 (aq) + KCl (aq)  AgCl (s) + KNO 3 (aq)

9. © 2009, Prentice-Hall, Inc. Metathesis (Exchange) Reactions Metathesis comes from a Greek word that means “to transpose.” It appears the ions in the reactant compounds exchange, or transpose, ions. AgNO 3 (aq) + KCl (aq)  AgCl (s) + KNO 3 (aq)

10. © 2009, Prentice-Hall, Inc. Precipitation Reactions When one mixes ions that form compounds that are insoluble (as could be predicted by the solubility guidelines), a precipitate is formed.

11. © 2009, Prentice-Hall, Inc. Acid-Base Reactions In an acid-base reaction, the acid donates a proton (H + ) to the base.

12. © 2009, Prentice-Hall, Inc. Neutralization Reactions Generally, when solutions of an acid and a base are combined, the products are a salt and water. CH 3 COOH (aq) + NaOH (aq)  CH 3 COONa (aq) + H 2 O (l)

13. © 2009, Prentice-Hall, Inc. Gas-Forming Reactions When a carbonate or bicarbonate reacts with an acid, the products are a salt, carbon dioxide, and water. CaCO 3 (s) + HCl (aq)  CaCl 2 (aq) + CO 2 (g) + H 2 O (l) NaHCO 3 (aq) + HBr (aq)  NaBr (aq) + CO 2 (g) + H 2 O (l) Similarly, when a sulfite reacts with an acid, the products are a salt, sulfur dioxide, and water. SrSO 3 (s) + 2 HI (aq)  SrI 2 (aq) + SO 2 (g) + H 2 O (l)

14. © 2009, Prentice-Hall, Inc. Gas-Forming Reactions Acids will react with sulfides to produce the noxious gas, hydrogen sulfide Na 2 S (aq) + H 2 SO 4 (aq)  Na 2 SO 4 (aq) + H 2 S (g) Ammonium salts and strong hydroxides will react to yield ammonia gas and water. NH 4 Cl (aq) + NaOH (aq)  NaCl (aq) + NH 3 (g) + H 2 O (l)

15. © 2009, Prentice-Hall, Inc. Oxidation-Reduction Reactions An oxidation occurs when an atom or ion loses electrons. A reduction occurs when an atom or ion gains electrons. One cannot occur without the other.

16. © 2009, Prentice-Hall, Inc. Oxidation Numbers Elements in their elemental form have an oxidation number of 0. The oxidation number of a monatomic ion is the same as its charge. The sum of the oxidation numbers in a neutral compound is 0. The sum of the oxidation numbers in a polyatomic ion is the charge on the ion

17. © 2009, Prentice-Hall, Inc. Displacement Reactions In displacement reactions, ions oxidize an element. The ions, then, are reduced.

18. © 2009, Prentice-Hall, Inc. Displacement Reactions In this reaction, silver ions oxidize copper metal. Cu (s) + 2 Ag + (aq)  Cu 2+ (aq) + 2 Ag (s)

19. © 2009, Prentice-Hall, Inc. Displacement Reactions The reverse reaction, however, does not occur. Cu 2+ (aq) + 2 Ag (s)  Cu (s) + 2 Ag + (aq) x

20. © 2009, Prentice-Hall, Inc. Activity Series

21. Writing Chemical Equations

22. © 2009, Prentice-Hall, Inc. Molecular Equation The molecular equation lists the reactants and products in their molecular form. AgNO 3 (aq) + KCl (aq)  AgCl (s) + KNO 3 (aq) Ionic Equation In the ionic equation all strong electrolytes (strong acids, strong bases, and soluble ionic salts) are dissociated into their ions. Ag + (aq) + NO 3 - (aq) + K + (aq) + Cl - (aq)  AgCl (s) + K + (aq) + NO 3 - (aq) *This more accurately reflects the species that are found in the reaction mixture.

23. © 2009, Prentice-Hall, Inc. Net Ionic Equation To form the net ionic equation, cross out anything that does not change from the left side of the equation to the right. Ag + (aq) + NO 3 - (aq) + K + (aq) + Cl - (aq)  AgCl (s) + K + (aq) + NO 3 - (aq)

24. © 2009, Prentice-Hall, Inc. Net Ionic Equation To form the net ionic equation, cross out anything that does not change from the left side of the equation to the right. The only things left in the equation are those things that change (i.e., react) during the course of the reaction. Ag + (aq) + Cl - (aq)  AgCl (s)

25. © 2009, Prentice-Hall, Inc. Net Ionic Equation To form the net ionic equation, cross out anything that does not change from the left side of the equation to the right. The only things left in the equation are those things that change (i.e., react) during the course of the reaction. Those things that didn’t change (and were deleted from the net ionic equation) are called spectator ions. Ag + (aq) + NO 3 - (aq) + K + (aq) + Cl - (aq)  AgCl (s) + K + (aq) + NO 3 - (aq)

26. © 2009, Prentice-Hall, Inc. Writing Net Ionic Equations 1.Write a balanced molecular equation. 2.Dissociate all strong electrolytes. 3.Cross out anything that remains unchanged from the left side to the right side of the equation. 4.Write the net ionic equation with the species that remain.

27. Solution Concentration

28. © 2009, Prentice-Hall, Inc. Molarity Two solutions can contain the same compounds but be quite different because the proportions of those compounds are different. Molarity is one way to measure the concentration of a solution. moles of solute volume of solution in liters Molarity (M) =

29. © 2009, Prentice-Hall, Inc. Mixing a Solution To create a solution of a known molarity, one weighs out a known mass (and, therefore, number of moles) of the solute. The solute is added to a volumetric flask, and solvent is added to the line on the neck of the flask.

30. © 2009, Prentice-Hall, Inc. Dilution One can also dilute a more concentrated solution by – Using a pipet to deliver a volume of the solution to a new volumetric flask, and – Adding solvent to the line on the neck of the new flask.

31. © 2009, Prentice-Hall, Inc. Dilution The molarity of the new solution can be determined from the equation M 1  V 1 = M 2  V 2, where M 1 and M 2 are the molarity of the concentrated and dilute solutions, respectively, and V 1 and V 2 are the volumes of the two solutions.

32. © 2009, Prentice-Hall, Inc. Titration Titration is an analytical technique in which one can calculate the concentration of a solute in a solution. NOT just for acids and bases!!!