Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Reactions of Acids with Bases Objectives Write ionic equations for neutralization reactions. Identify the products of a neutralization reaction. Describe the composition of a salt. Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Reactions of Acids with Bases Bellringer You have learned that acids and bases dissociate into ions in solution. The characteristic ions are the hydronium, or H 3 O +, ion for acids and the hydroxide, or OH –, ion for bases. Below are listed several reactions between acids and bases. From what you know about reactions, acids, and bases, predict what the products of the following reactions will be. 1. HCl(aq) + NaOH(aq)  ______ + H 2 O(l) 2. HCl(aq) + KOH(aq)  KCl(aq) + ______ 3. HNO 3 (aq) + KOH(aq)  ______ + ______ 4. H 2 SO 4 (aq) + Ca(OH) 2 (aq)  ______ + ______ 5. HBr(aq) + AgOH(aq)  ______ + ______ 6. HClO 4 (aq) + NaOH(aq)  ______ + ______ 7. 2HNO 3 (aq) + Ba(OH) 2 (aq)  ______ + ______ 8. H 2 SO 4 (aq) + 2NH 4 OH(aq)  ______ + ______ Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Reactions of Acids with Bases Acid-Base Reactions A reaction between an acid and a base is a neutralization reaction. Neutralization is an ionic reaction. Example: A strong acid such as HCl ionizes completely in solution: HCl + H 2 O  Cl – + H 3 O + A strong base such as NaOH ionizes completely in solution: NaOH  Na + + OH – The total neutralization reaction is the following: Cl – + H 3 O + + Na + + OH –  Na + + Cl – + 2H 2 O Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Neutralization Reaction Section 2 Reactions of Acids with Bases Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Reactions of Acids with Bases Acid-Base Reactions, continued Neutralization reactions form water and a salt. A salt is an ionic compound that forms when a metal atom or a positive radical replaces the hydrogen of an acid. Not all neutralization reactions produce neutral solutions. The final pH of the solution depends on: the amounts of acid and base that are combined whether the acid and base are strong or weak Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Salt Section 2 Reactions of Acids with Bases Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Reactions of Acids with Bases Acid-Base Reactions, continued A titration is a neutralization reaction in which the known concentration of one solution is used to determine the unknown concentration of another solution. When the amounts of acid and base added are equal, an equivalence point will be reached. The equivalence point will be at pH 7 for the titration of a strong acid with a strong base, but if a weak acid or base is involved, the equivalence point will not be neutral. Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Titration Section 2 Reactions of Acids with Bases Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Equivalence and End Points Section 2 Reactions of Acids with Bases Chapter 8

Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Reactions of Acids with Bases Salts To a chemist, a salt can be almost any combination of cations and anions. Common table salt contains sodium chloride, NaCl, which is a salt that is formed from the reaction of hydrochloric acid with sodium hydroxide. Salts are useful substances, and are all around us. Examples: sodium hydrogen carbonate, baking soda silver bromide and silver iodide, in photographic film barium sulfate, sometimes used in taking X rays calcium carbonate, in chalk, limestone, and marble Chapter 8