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Chapter 10 Acids and Bases

10.1 Acids and Bases

10.2 Conjugate Acid-Base Pairs

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Arrhenius acids Produce H+ ions in water. H2O

HCl H+(aq) + Cl- (aq) Are electrolytes. Have a sour taste. Corrode metals. React with bases to form

salts and water.

Acids

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Arrhenius bases Produce OH- ions in

water. Taste bitter or chalky. Are electrolytes. Feel soapy and slippery. React with acids to

form salts and water.

Bases

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Comparing Acids and Bases

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Names of Acids Acids with H and one nonmetal are named

with the prefix hydro- and end with -ic acid.HCl hydrochloric acid

Acids with H and a polyatomic ion are named by changing the end of an –ate ion to -ic acid and an –ite ion to -ous acid.

HClO3 chloric acid

HClO2 chlorous acid

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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

Some Common Bases

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According to the BrØnsted-Lowry theory, Acids are hydrogen ion (H+) donors. Bases are hydrogen ion (H+) acceptors.

donor acceptor hydronium ion

HCl + H2O H3O+ + Cl-

+ -

+ +

BrØnsted-Lowry Acids and Bases

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When NH3 dissolves in water, a few NH3 molecules react with water to form ammonium ion NH4

+ and a hydroxide ion.

NH3 + H2O NH4+(aq) + OH- (aq)

acceptor donor

+ - + +

NH3, A Bronsted-Lowry Base

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Conjugate Acids and Bases An acid that donates H+ forms a conjugate base. A base that accepts a H+ forms a conjugate acid. In an acid-base reaction, there are two conjugate acid-

base pairs.

acid 1 conjugate base 1

+ +

base 2 conjugate acid 2HF H2O H3O+ F-

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Conjugate Acid-Base Pairs

A conjugate acid-base pair is two substances related by a loss or gain of H+.

+ +

acid 1– conjugate base 1

base 2– conjugate acid 2

HF H2O H3O+ F-

HF, F-

H2O, H3O+