General, Organic, and Biological Chemistry Fourth Edition Karen Timberlake Chapter 10 Acids and Bases 10.1 Acids and Bases Lectures © 2013 Pearson Education, Inc.

Arrhenius Acids Arrhenius acids produce H+ ions in water. H2O have a sour taste. turn blue litmus paper red. corrode some metals. Citrus fruits are sour because of the presence of acids.

Naming Acids Acids with H and a nonmetal are named with the prefix hydro− and end with −ic acid. HCl hydrochloric acid Acids with H and an oxygen-containing 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. ClO3− chlorate HClO3 chloric acid ClO2− chlorite HClO2 chlorous acid

Naming Some Common Acids

Learning Check Select the correct name for each of the following acids. 1. HBr A. bromic acid B. bromous acid C. hydrobromic acid 2. H2CO3 A. carbonic acid B. hydrocarbonic acid C. carbonous acid 3. HBrO2 A. bromic acid B. hydrobromous acid C. bromous acid

Solution 1. HBr C. hydrobromic acid The name of an acid with H and one nonmetal uses the prefix hydro− and ends with −ic acid. 2. H2CO3 A. carbonic acid An acid with H and a polyatomic ion, bicarbonate, HCO3− is named by changing the end of the ion’s name from −ate to −ic acid. 3. HBrO2 C. bromous acid This acid of bromite, (BrO2−) is bromous acid.

Bases Arrhenius bases produce OH− ions in water. taste bitter or chalky. feel soapy and slippery. turn red litmus paper blue. turn the phenolphthalein indicator pink.

Some Common Bases Bases with OH ions are named as the hydroxide of the metal in the formula. NaOH sodium hydroxide KOH potassium hydroxide Ba(OH)2 barium hydroxide Al(OH)3 aluminum hydroxide Fe(OH)3 iron (III) hydroxide

Base – Ca(OH)2 Slaked Lime Calcium hydroxide, Ca(OH)2, also called slaked lime, is used to produce beverages, neutralize acids, and in dentistry as a filler for root canals.

Learning Check 1. HNO2 A. iodic acid 2. Ca(OH)2 B. sulfuric acid Match the formulas with the names. 1. HNO2 A. iodic acid 2. Ca(OH)2 B. sulfuric acid 3. H2SO4 C. sodium hydroxide 4. HIO3 D. nitrous acid 5. NaOH E. calcium hydroxide

Solution 1. HNO2 D. nitrous acid 2. Ca(OH)2 E. calcium hydroxide Match the formulas with the names. 1. HNO2 D. nitrous acid 2. Ca(OH)2 E. calcium hydroxide 3. H2SO4 B. sulfuric acid 4. HIO3 A. iodic acid 5. NaOH C. sodium hydroxide

Comparing Acids and Bases

Learning Check Identify each as a characteristic of an acid or base. ____ A. has a sour taste ____ B. produces OH− in aqueous solutions ____ C. has a bitter taste ____ D. is an electrolyte ____ E. produces H+ in aqueous solutions

Solution Identify each as a characteristic of an acid or base. acid A. has a sour taste base B. produces OH− in aqueous solutions base C. has a bitter taste acid and base D. is an electrolyte acid E. produces H+ in aqueous solutions

Brønsted–Lowry Acids According to the Brønsted–Lowry theory, acids donate a proton (H+). In the reaction of hydrochloric acid and water, HCl is the acid that donates H+, and H2O is the base that accepts H+.

Brønsted–Lowry Bases According to the Brønsted–Lowry theory, bases accept a proton (H+). In the reaction of ammonia and water, NH3 is the base that accepts H+, and H2O is the acid that donates H+.

Conjugate Acid–Base Pairs In any acid–base reaction, there are two conjugate acid–base pairs. Each is related by the loss and gain of H+. One occurs in the forward direction. One occurs in the reverse direction. conjugate acid–base pair 1 HA conjugate acid–base pair 2

Conjugate Acids and Bases, HF The first conjugate acid–base pair is HF/F−. HF loses one H+ to form its conjugate base F−. The other conjugate acid–base pair is H2O/H3O+. H2O acts as a base accepting one H+ to form its conjugate acid H3O+.

Conjugate Acids and Bases, NH3 The first conjugate acid–base pair is NH3/NH4+. NH3, acts as a base by gaining H+ to form its conjugate acid NH4+. The other conjugate acid–base pair is H2O/OH–. H2O acts as an acid by donating one H+ to form its conjugate base OH−.

Learning Check 1. Write the conjugate base of the following. A. HBr B. H2S C. H2CO3 2. Write the conjugate acid of the following. A. NO2− B. NH3 C. OH−

Solution 1. Write the conjugate base of the following. Remove H+ to write the conjugate base. A. HBr Br − B. H2S HS− C. H2CO3 HCO3− 2. Write the conjugate acid of the following. Add H+ to write the conjugate acid. A. NO2− HNO2 B. NH3 NH4+ C. OH− H2O

Learning Check A. HNO2, NO2− B. H2CO3, CO32− C. HCl, ClO4− D. HS−, H2S Identify the sets that contain acid–base conjugate pairs. A. HNO2, NO2− B. H2CO3, CO32− C. HCl, ClO4− D. HS−, H2S E. NH3, NH4+

Solution A. HNO2, NO2− D. HS−, H2S E. NH3, NH4+ Identify the sets that contain acid–base conjugate pairs. A. HNO2, NO2− D. HS−, H2S E. NH3, NH4+

Learning Check 1. The conjugate base of HCO3− is A. CO32−. B. HCO3−. C. H2CO3. 2. The conjugate acid of HCO3− is A. CO32−. B. HCO3−. C. H2CO3. 3. The conjugate base of H2O is A. OH−. B. H2O. C. H3O+. 4. The conjugate acid of H2O is

Solution 1. (A) The conjugate base of HCO3− is, CO32−. 2. (C) The conjugate acid of HCO3− is H2CO3. 3. (A) The conjugate base of H2O is OH−. 4. (C) The conjugate acid of H2O is H3O+.

Learning Check Identify the acid–base conjugate pairs.

Solution Identify the acid–base conjugate pairs. conjugate acid–base pair conjugate acid–base pair conjugate acid–base pair conjugate acid–base pair conjugate acid–base pair conjugate acid–base pair