Chapter 24: Acids, Bases, and Salts

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Chapter 24 Acids, Bases, and Salts

• Christopher Chui

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Arrhenius Theory

• An acid produces H in water solution a base
  produces OH- in water solution
• Acids, bases, and salts are called electrolytes
  because they conduct a current when dissolved in
  water

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Bronsted-Lowry Theory

• In a chemical reaction, any substance that
  donates a proton is an acid and any substance
  that accepts a proton is a base
• Acid base gt conjugate base conjugate acid

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Lewis Theory

• An acid is an electron-pair acceptor a base is
  an electron-pair donor
• Lewis base Lewis acid gt Addition product
• A substance that is an acid or base under the
  Arrhenius theory is also an acid or base under
  the Lewis and the Bronsted-Lowry theories

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Naming Acids

• Binary acids contain only two elements
• The names of binary acids begin with hydro- and
  end in ic
• Ternary acids are acids that contain three
  elements
• If a 2nd acid is formed with one less oxygen
  atom, suffix ous is used
• If a 3rd acid containing still fewer oxygen atom,
  it is given the prefix hypo- and the suffix ous
• Acids containing more oxygen than the common form
  are named by adding the prefix per- to the common
  name
• Bases are named by the name of metallic ion
  hydroxide

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Naming Organic Acids and Bases

• Carboxylic acids are named by adding the ending
  oic acid to the name of the hydrocarbon
• Organic bases contain nitrogen
• Amines are named by adding the ending -amine to
  the name of the hydrocarbon
• Amines contain NH2

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Acid-Base Behavior

• Metals tend to form bases nonmetals tend to form
  acids
• An amphoteric substance is one that can act as
  either an acid or a base
• An acidic anhydride is an oxide that produces an
  acid when dissolved in water
• A basic anhydride is an oxide that produces a
  base when dissolved in water
• Anhydrous means without water

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Definition of a Salt

• An acid-base neutralization reaction produces a
  salt
• Acidic or basic salts may be formed by
  neutralization reactions. These salts are not
  neutral in solution

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Strengths of Acids and Bases

• Strong acids ionize completely in water solution
• Strong bases dissociate completely in water
  solution
• Weak acids and bases ionize only slightly in
  water solution

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Net Ionic Equations

• Spectator ions are not involved in the reaction
  and are not written in the net ionic equation
• Some substances are written as molecules others
  are written as ions
• An acid may contain more than one ionizable
  hydrogen atom. Such an acid is called a
  polyprotic acid

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7 Rules for Acids and Bases

• Binary acids HCl, HBr, and HI are strong all
  others are weak. Strong acids are ionic
• Ternary acids If oxygen atoms are more than
  hydrogen atoms by 2 or more, the acid is strong
• Polyprotic acids In the 2nd and subsequent
  ionizations, the acids are always weak
• Bases Hydroxides of Gp1 and Gp2 are strong bases
  except beryllium
• Salts Soluble salts are ionic
• Oxides Oxides are always in molecular form
• Gases Gases are always in molecular form

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Ionization Constant

• Equilibrium constant, Keq, is defined to be the
  concentrations of products divided by that of the
  reactants
• The product of Keq and the conc of water is
  called the ionization constant, Ka
• Percent ionization can be calculated from the
  ratio obtained by comparing the conc of an ion in
  solution to the conc of the solute before it
  ionized
• If a common ion is added, the ionization constant
  remains the same, although it increases the conc
  of one of the products of the ionization