1 Acids and Bases

2 In the expression for [H 3 O + ] / [H+] 1 x 10 -exponent the exponent = pH [H 3 O + ] = 1 x 10 -pH M pH

3 pH Range Neutral [H + ] > [OH - ] [H + ] = [OH - ] [OH - ] > [H + ] Acidic Basic

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5 Some [H 3 O + ] and pH [H 3 O + ] pH 1 x M 5 1 x M 9 1 x M 11

6 pH of Some Common Acids gastric juice1.0 lemon juice2.3 vinegar2.8 orange juice3.5 coffee5.0 milk6.6

7 pH of Some Common Bases blood 7.4 tears 7.4 seawater 8.4 milk of magnesia10.6 household ammonia11.0

8 Examples A. The [H 3 O + ] of tomato juice is 1 x M. What is the pH of the solution? 1) - 42)43)8 B. The [OH - ] of an ammonia solution is 1 x M. What is the pH of the solution? 1) 32)113)-11

9 pH Questions Identify each solution as 1. acidic 2. basic3. neutral A. ___ HCl with a pH = 1.5 B. ___ Pancreatic fluid [H + ] = 1 x M C. ___ Sprite soft drink pH = 3.0 D. ___ pH = 7.0 E. ___ [OH - ] = 3 x M F. ___ [H + ] = 5 x

10 Acids Produce H + (as H 3 O + ) ions in water Conduct Electricity (electrolytes) Taste sour Corrode metals React with bases to form salts and water Formulas start with H React with metals to form H 2 gas. Change the color of indicators – (for example: blue litmus turns to red)

Acids Affect Indicators, by changing their color Blue litmus paper turns red in contact with an acid (and red paper stays red). 11

12 Some Common Acids HCl hydrochloric acid HNO 3 nitric acid H 3 PO 4 phosphor ic acid H 2 SO 4 sulfur ic acid CH 3 COOH acet ic acid

13 Bases Produce OH - ions in water Formulas end in OH Taste bitter, chalky Are electrolytes Feel soapy, slippery React with acids to form salts and water

14 Arrhenius Acids and Bases Acids produce H + in aqueous solutions water HCl H + (aq) + Cl - (aq) Bases produce OH - in aqueous solutions water NaOH Na + (aq) + OH - (aq)

15 Learning Check AB1 Describe the solution in each of the following as: 1) acid 2) base or 3)neutral. A. ___soda B. ___soap C. ___coffee D. ___ wine E. ___ water F. ___ grapefruit

16 Solution AB1 Describe each solution as: 1) acid 2) base or 3) neutral. A. _1_ soda B. _2_ soap C. _1_ coffee D. _1_ wine E. _3_ water F. _1_ grapefruit

17 Learning Check AB2 Identify each as characteristic of an A) acid or B) base ____ 1. Sour taste ____ 2. Produces OH - in aqueous solutions ____ 3. Chalky taste ____ 4. Is an electrolyte ____ 5. Produces H + in aqueous solutions

18 Solution AB2 Identify each as a characteristic of an A) acid or B) base _A_ 1. Sour taste _B_ 2. Produces OH - in aqueous solutions _B_ 3. Chalky taste A, B 4. Is an electrolyte _A_ 5. Produces H + in aqueous solutions

19 Some Common Bases NaOHsodium hydroxide KOH potassium hydroxide Ba(OH) 2 barium hydroxide Mg(OH) 2 magnesium hydroxide Al(OH) 3 aluminum hydroxide

20 Learning Check AB4 Identify each formula as an acid or base: A. ___ HNO 2 B. ___Ca(OH) 2 C. ___H 2 SO 4 D. ___HCl E. ___NaOH

21 Learning Check AB5 Acid, Base Name or Salt CaCl 2 _______________________ KOH_______________________ Ba(OH) 2 ______ _________________ HBr_______________________ H 2 SO 4 ________________________

22 Neutralization Reactions * When acid and bases with equal amounts of hydrogen ion H + and hydroxide ions OH - are mixed, the resulting solution is neutral. *Products are a salt and water *Salts formulas do not start with H or end in OH NaOH (aq) + HCl(aq) NaCl + H 2 O base acid salt water Ca(OH) HCl CaCl 2 + 2H 2 O base acid salt water

Salt Hydrolysis A salt is an ionic compound that: –comes from the anion of an acid –comes from the cation of a base –is formed from a neutralization reaction –some neutral; others acidic or basic “Salt hydrolysis” - a salt that reacts with water to produce an acid or base 23

24 Learning Check AB5 Acid, Base Name or Salt CaCl 2 _______________________ KOH_______________________ Ba(OH) 2 ______ _________________ HBr_______________________ H 2 SO 4 ________________________

25 Solution AB5 Acid, Base Name or Salt CaCl 2 saltcalcium chloride KOHbasepotassiuim hydroxide Ba(OH) 2 basebarium hydroxide HBracidhydrobromic acid H 2 SO 4 acidsulfuric acid