CHAPTER 15 ACIDS

1
CHAPTER 15ACIDS BASES

• Section 15.1
• Properties of Acids Bases

2
Properties of Acids

• Taste Sour. Dont try this at home!
• Conduct electricity
• Some are strong, some are weak electrolytes.
• React with metals to form hydrogen gas.
• Change indicators (litmus red).
• React with hydroxides (OH-) to form water and a
  salt.

3
Naming Acids

• A binary acid contains 2 elements (one is H).
• To name binary acids
• It begins with hydro
• Drop ending of ion
• Add ic
• Use acid at end.
• Oxyacid an acid that contains H, O, and a third
  element. See pg. 455.

4
Properties of Bases

• React with acids to form water and a salt.
• Taste bitter.
• Feel slippery (Dont try this either).
• Can be strong or weak electrolytes.
• Change indicators (litmus blue).

5
Naming Bases

• Naming bases is the same as naming ionic
  compounds (Remember Chapter 7???)
• Write name of metal.
• Use hydroxide at end if the base ends in OH-.

6
Arrhenius Definition

• Acids produce hydrogen ions (H) in aqueous
  solution.
• Bases produce hydroxide ions (OH-) when dissolved
  in water.
• Limits to aqueous solutions solutions dissolved
  in water.
• Says there is only one kind of base.
• NH3 (ammonia) could not be an Arrhenius base.
  Why????

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CHAPTER 15ACIDS BASES

• Section 15.2
• BrØnsted-Lowry
• Acids Bases

8
BrØnsted-Lowry Definitions

• An acid is an proton (H) donor and a base is a
  proton acceptor.
• Acids and bases always come in pairs.
• HCl is an acid.
• When it dissolves in water it gives its proton to
  water.
• HCl(g) H2O(l) H3O Cl-
• Water is a base makes hydronium ion.

9
Conjugate Acids/Conjugate Bases

• According to Bronsted-Lowry
• when an acid gives up its proton, it becomes a
  conjugate base (CB). Look for the (-) charge.
• When when a base gains a proton, it becomes a
  conjugate acid (CA). Look for the () charge.
• The stronger the original acid or base, the
  weaker it conjugate base or conjugate acid.

10
Conjugate Acids/Conjugate Bases

• Water can be a base.
• HA(aq) H2O(l) H3O(aq) A-(aq)
• Acid Base CA CB
• Water can be an acid.
• B(aq) H2O(l) BH(aq) OH-(aq)
• Base Acid CA CB
• This makes water amphoteric.
• NH3(aq)H2O(l) NH4(aq)OH-(aq)

11
Polyprotic Acids

• Some compounds have more than 1 ionizable
  hydrogen.
• HNO3 nitric acid - monoprotic
• H2SO4 sulfuric acid - diprotic - 2 H
• H3PO4 phosphoric acid - triprotic - 3 H

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CHAPTER 15ACIDS BASES

• Section 15.3
• Neutralization Reactions

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Neutralization Reactions

• Acid Base Salt water
• Salt an ionic compound
• Water HOH
• Really just double replacement.
• HNO3 KOH
• HCl Mg(OH)2
• H2SO4 NaOH

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Lewis Acids Bases

• Another classification for acids and bases that
  is based on bonding.
• Its the most general definition.
• Allows substances that dont contain H to still
  be defined as acids.
• A Lewis acid accepts an electron pair.
• A Lewis base donates an electron pair.
• In a Lewis acid-base reaction, an electron pair
  donor electron pair acceptor form one or more
  covalent bonds.

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Lewis Acids and Bases
F
H
B
F
N
H
F
H
16
Lewis Acids and Bases

• Boron triflouride (BF3) wants more electrons.

F
H
B
F
N
H
F
H
17
Lewis Acids and Bases

• Boron triflouride (BF3) wants more electrons.
• BF3 is Lewis base NH3 is a Lewis Acid.

F
H
F
H
B
N
F
H