ACIDS, BASES,

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ACIDS, BASES, SALTS
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Properties of Acids

• Sour taste
• Electrolytes aqueous solutions conduct an
  electric current
• React with bases to form water and a salt.
  (Neutralization Reaction)
• React with most metals to produce H2(g)
• Acids turn litmus red

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Electrolyte

• Substance that dissolves in H2O to produce a
  solution that conducts an electric current.
• Acids, bases, salts are electrolytes form
  ions in H2O.
• NaCl(s) ? Na(aq) Cl-(aq)

Memory Jogger
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Testing Conductivity

• Conductivity test
• Animation
• Strong electrolyte animation
• Metal
• Wax

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Which metals react with acids?

• See Table J.
• All the metals above H2 react with acids.
• Cu, Ag, and Au do not react with acids.

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2HCl Mg ? MgCl2 H2

• Mg is above H2 in Table J so reaction proceeds.
• Single replacement
• Redox

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Properties of Bases

• Bitter taste
• Slippery or soapy feeling
• Electrolytes
• React with acids to produce water and a salt
• Bases turn litmus blue

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Formulas of Acids

• General format HX where X is a nonmetal such as
  F, Cl, Br, I or X is a negative polyatomic ion
  (Table E)
• Some acids have 2 or 3 Hs
• Ex HF, H2S, H3PO4
• Organic Acids format R-COOH where R is CxHy

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Formulas of Bases

• General Format MOH where M is a metal.
• Ex NaOH, Ca(OH)2
• NH3 is the exception its a base, too.
• CH3OH is NOT a base. WHY?

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Electrolytes

• Substances that conduct when dissolved in water.
• Acids start with H or end in COOH
• Bases M-OH or NH3
• Salts Metal Nonmetal

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Identify the Electrolytes

• CCl4
• HNO3
• C5H12
• K3PO4
• CH3OCH3
• LiOH
• HI
• (NH4)2SO4
• C12H22O11

NO

• NaCl
• C2H5OH
• H2SO4
• NaOH
• C6H12O6
• CaI2
• HF
• Mg(OH)2
• C3H7OH

Yes - S
Yes - A
NO
NO
Yes - A
Yes - S
Yes - B
NO
NO
Yes - B
Yes - S
Yes - A
Yes - A
Yes - S
Yes - B
NO
NO
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Acid, Base, or Neutral?

• Turns out all H2O contains some H and some OH-
• Pure H2O concentrations are very low.
• H OH- 1 X 10-7 Molar.
• When H OH-, solution is neutral.
• Acidic solution H gt OH-
• Basic solution OH- gt H

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Water self-ionization

• H2O(l) H2O(l) ? H3O(aq) OH-(aq)
• H3O is called hydronium ion
• OH- is called hydroxide ion
• H2O(l) ? H(aq) OH-(aq)
• In reality, H and H3O are used interchangeably.
• H is called a proton or a hydrogen ion.

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Self-ionization of water
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Draw the Dot Diagram showing the Autoionization
of H2O

• Rem Hydrogen atoms contain 1 proton and 1
  electron.
• H contains only 1 proton, so it can be referred
  to as either a hydrogen ion or as a proton.
• H3O is called hydronium ion.

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Arrhenius Acid

• Substance that contains hydrogen ionizes to
  produce H as the only positive ion in aqueous
  solution.
• HCl(g) ? H(aq) Cl-(aq)
• HNO3 ? H(aq) NO3-(aq)

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Arrhenius Base

• A substance that contains a hydroxide group
  ionizes to produce OH- as the only negative ion
  in aqueous solution.
• NaOH(s) ? Na(aq) OH-(aq)

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Arrhenius Salt

• Electrolytes where H is not the only positive
  ion and OH- is not the only negative ion in aq.
  solution.
• Ex NaCl, CaBr2,KNO3, NH4I

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Salts in Water

• NaCl(s) ? Na(aq) Cl-(aq)
• CaBr2(s) ? Ca2(aq) 2Br-(aq)
• KNO3(s) ? K(aq) NO3-(aq)
• NH4I(s) ? NH4(aq) I-(aq)

Memory Jogger
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Arrhenius Model has limitations

• Dont always use H2O as the solvent.
• Arrhenius model only applies when H2O is the
  solvent.
• Doesnt explain all cases
• NH3 doesnt contain OH- but it produces OH-.

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Ionization of Acid Arrhenius

• HCl ? H Cl-
• HBr ? H Br-
• HNO3 ? H NO3-
• Looks like a salt falling apart, so it can also
  be called dissociation.

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Ionization of Base Arrhenius

• NaOH ? Na OH-
• LiOH ? Li OH-
• KOH ? K OH-

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Alternate Theory Bronsted-Lowry

• Acid a proton donor
• All Arrhenius acids are Bronsted-Lowry Acids.
• HX(g) H2O(l) ? H3O X-
• H forms a molecule-ion bond with the water
  molecule ? H3O, named hydronium ion.

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Ionization of Bronsted-Lowry Acids

• HCl H2O ? H3O Cl-
• HNO3 H2O ? H3O NO3-
• H2SO4 H2O ? H3O HSO4-
• HSO4- H2O ? H3O SO4-2

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Bronsted-Lowry Base

• Base proton acceptor.
• OH- is a base. H OH- ? H2O
• Not restricted to aqueous solution.
• NH3 H2O ? NH4 OH-
• NH3 is a base!

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Amphoteric

• Substance that can act as both an acid a base
• Water is amphoteric
• HX(g) H2O(l) ? H3O X- H20 base
• NH3 H2O ? NH4 OH- H2O acid

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Water is amphoteric!
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Movies

• Acid Movie
• Base Movie
• Electrolyte Movie
• Strong vs. Weak Electrolyte Movie

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Vocabulary Interlude

• Monoprotic Acid has 1 acidic hydrogen
• HCl, HF, HNO3
• Diprotic Acid has 2 acidic hydrogens
• H2SO4
• Triprotic Acid has 3 acidic hydrogens
• H3PO4
• All polyprotic acids ionize in steps.

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Vocabulary

• Monohydroxy Base has 1 OH- group
• Dihydroxy Base has 2 OH- groups
• Trihydroxy Base - has 3 OH- groups

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Vocabulary

• Strong vs. Weak
• The terms strong and weak DO NOT refer to
  concentration. Strong and weak refer to the
  degree or extent of the ionization.
• Strong means lots of ionization almost 100.
• Weak means little ionization 1 or 2.

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Strong Acids

• Strong acids ionize almost completely
• HCl ? H Cl-
• Lots of H and Cl-. Very little HCl.
• Very good electrolytes!

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Strong Acids Ionize Almost Totally
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Weak Acids

• Weak acids dont ionize very much
• HC2H3O2 ? H C2H3O2-
• Lots of HC2H3O2. Very little H or C2H3O2-.
• Weak Electrolytes!

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Weak Acids Ionize to a Lesser Extent
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Strong Bases Ionize Almost Totally
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Weak Bases Undergo Partial Ionization