Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Chapter 8 Acids and Bases 8.1 Acids and Bases 1

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Acids Arrhenius acids produce H + ions in water H 2 O(l) HCl(g)  H + (aq) + Cl  (aq) are electrolytes have a sour taste turn litmus red neutralize bases 2

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Acids Acids with H and a nonmetal are named with the prefix hydro and end with ic acid. HClhydrochloric acid Acids with H and a polyatomic ion are named by changing the end of the name of the polyatomic ion from ate to ic acid or ite to ous acid ClO 3  chlorate HClO 3 chloric acid ClO 2  chlorite HClO 2 chlorous acid 3

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Names of Common Acids 4

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Select the correct name for each of the following acids. 1. HBr A. bromic acid B. bromous acid C. hydrobromic acid 2. H 2 CO 3 A. carbonic acid B. hydrocarbonic acid C. carbonous acid 3. HBrO 2 A. bromic acid B. hydrobromous acid C. bromous acid 5

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 1. HBrBr , bromideC. hydrobromic acid The name of an acid with H and a nonmetal uses the prefix hydro and ends with ic acid. 2. H 2 CO 3 CO 3 2 , carbonate A. carbonic acid An acid with H and a polyatomic ion ending in ate is called an ic acid. 3. HBrO 2 BrO 2 , bromiteC. bromous acid An acid with H and a polyatomic ion ending in ite is called an ous acid. 6

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Bases Arrhenius bases produce OH  ions in water taste bitter or chalky are electrolytes feel soapy and slippery neutralize acids 7

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Naming Bases Bases with OH  ions are named as the hydroxide of the metal in the formula. NaOHsodium hydroxide KOHpotassium hydroxide Ba(OH) 2 barium hydroxide Al(OH) 3 aluminum hydroxide Fe(OH) 3 iron(III) hydroxide 8

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Match the formulas with the names. 1. ___HNO 2 A. iodic acid 2. ___Ca(OH) 2 B. sulfuric acid 3. ___H 2 SO 4 C. sodium hydroxide 4. ___HIO 3 D. nitrous acid 5. ___NaOHE. calcium hydroxide 9

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Match the formulas with the names. 1. _D__HNO 2 D. nitrous acid 2. _E__Ca(OH) 2 E. calcium hydroxide 3. _B__H 2 SO 4 B. sulfuric acid 4. _A__HIO 3 A. iodic acid 5. _C__NaOHC. sodium hydroxide 10

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Brønsted–Lowry Acids and Bases According to the Brønsted – Lowry theory, acids donate a proton (H + ) bases accept a proton (H + ) 11

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. NH 3, a Brønsted–Lowry Base In the reaction of ammonia and water, NH 3 is the base that accepts H + H 2 O is the acid that donates H + 12

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Characteristics of Acids and Bases 13

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check In each of the following identify the Brønsted – Lowry acid and base: A. HNO 3 (aq) + H 2 O(l)  H 3 O + (aq) + NO 3  (aq) B. HF(aq) + H 2 O(l) H 3 O + (aq) + F  (aq) 14

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution In each of the following identify the Brønsted – Lowry acid and base: A. HNO 3 (aq) + H 2 O(l)  H 3 O + (aq) + NO 3  (aq) acid base B. HF(aq) + H 2 O(l) H 3 O + (aq) + F  (aq) acid base 15

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Identify each as a characteristic of an A. acid or B. base. ____1. has a sour taste ____2. produces OH  in aqueous solutions ____3. has a chalky taste ____4. is an electrolyte ____5. produces H + in aqueous solutions 16

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Identify each as a characteristic of an A. acid or B. base. A1. has a sour taste B2. produces OH  in aqueous solutions B3. has a chalky taste A, B4. is an electrolyte A5. produces H + in aqueous solutions 17

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Conjugate Acid–Base Pairs In any acid – base reaction, there are two conjugate acid – base pairs. Each pair is related by the loss and gain of H +. One pair occurs in the forward direction. One pair occurs in the reverse direction. conjugate acid – base pair 1 HA + B A  + BH + conjugate acid – base pair 2 18

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Conjugate Acid–Base Pairs In this acid – base reaction, an acid, HF, donates H + to form its conjugate base, F  a base, H 2 O, accepts H + to form its conjugate acid, H 3 O + there are two conjugate acid – base pairs 19

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Conjugate Acid–Base Pairs In this acid – base reaction, the first conjugate acid – base pair is HF, which donates H + to form its conjugate base, F  the other conjugate acid – base pair is H 2 O, which accepts H + to form its conjugate acid, H 3 O + each pair is related by a loss and gain of H + 20

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Conjugate Acid–Base Pairs In the reaction of NH 3 and H 2 O, one conjugate acid – base pair is NH 3 /NH 4 + the other conjugate acid – base is H 2 O/H 3 O + 21

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 1. Write the conjugate base of each of the following: A. HBr B. H 2 S C. H 2 CO 3 2. Write the conjugate acid of each of the following: A. NO 2  B. NH 3 C. OH  22

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 1. Write the conjugate base of each of the following: Subtract an H + from each acid to get the conjugate base: A. HBr – H +  Br  B. H 2 S– H +  HS  C. H 2 CO 3 – H +  HCO 3  23

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution 2. Write the conjugate acid of each of the following: Add an H + to each base to get the conjugate acid. A. NO 2  + H +  HNO 2 B. NH 3 + H +  NH 4 + C. OH  + H +  H 2 O 24

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check Identify the sets that contain acid – base conjugate pairs. 1. HNO 2, NO 2  2. H 2 CO 3, CO 3 2  3. HCl, ClO 4  4. HS , H 2 S 5. NH 3, NH

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solution Identify the sets that contain acid – base conjugate pairs. 1. HNO 2, NO 2  acid, conjugate base 2. H 2 CO 3, CO 3 2  not acid – base conjugate pair 3. HCl, ClO 4  not acid – base conjugate pair 4. HS , H 2 Sbase, conjugate acid 5. NH 3, NH 4 + base, conjugate acid 26

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Learning Check 1. The conjugate base of HCO 3  is A. CO 3 2  B. HCO 3  C. H 2 CO 3 2. The conjugate acid of HCO 3  is A. CO 3 2  B. HCO 3  C. H 2 CO 3 3. The conjugate base of H 2 O is A. OH  B. H 2 O C. H 3 O + 4. The conjugate acid of H 2 O is A. OH  B. H 2 O C. H 3 O + 27

Chemistry: An Introduction to General, Organic, and Biological Chemistry, Eleventh Edition Copyright © 2012 by Pearson Education, Inc. Solutions 1. The conjugate base of HCO 3  is A. CO 3 2  B. HCO 3  C. H 2 CO 3 2. The conjugate acid of HCO 3  is A. CO 3 2  B. HCO 3  C. H 2 CO 3 3. The conjugate base of H 2 O is A. OH  B. H 2 O C. H 3 O + 4. The conjugate acid of H 2 O is A. OH  B. H 2 O C. H 3 O + 28