Acids

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Acids and Bases
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Identifying Acids and Bases
contains H ions as the cation, with and other
element as the anion

• Acids
• Acid (anhydrides)
• Bases
• Base (anhydrides)
• Salts

H2SO4 HI
Non-metal oxide
P2O5
Contains OH- as the anion Combined with a cation
Ca(OH)2
Al2O3
A metal with oxygen
Ionic compound Formed from a cation and an anion
Metal and non-metal
Mg F2 KCl LiBr
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Acid / Base Chemistry

• Hydrogen ion concentration H
• Hydroxide ion concentration OH-
• Pure H20 neutral substance
• ph7 and HOH-
• H2O will self-dissociate
• H20 gt H OH-
• Note the number of H2O molecules that will self
  dissociate is very small only 2 molecules per a
  billion, therefore H2O is unchanged.

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Acid / Base Chemistry

• Kw - is the ion product constant for water
• Kw 1.0 x 10-14 M2
• Kw H OH-
• FOR H2OKw 1.0 x 10-7 M1.0 x 10-7M
• - there is an indirect relationship between H
  and OH-

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Acid / Base Chemistry

• Calculate OH- if H is 1.0 x 10-2 M
• Kw H OH-
• OH- Kw 1.0 x 10-14M2
• H 1.0 x 10-2M
• OH- 1.0 X 10 12 M

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Acid / Base Chemistry

• Calculate H if OH- is 6.5 x 10-11 M
• Kw H OH-
• H Kw 1.0 x 10-14M2
• OH- 6.5 x 10-11M
• H
• H will tell us if a soln is acidic or basic.

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pH 1- 6 H 1.0 x 10 M 1.0 x 10 M H gt
OH-
Acidic solutions
-1
-6
pH 7 H OH- 1.0 x 10 M for both
Neutral solutions
-7
pH 8 -14 H 1.0 x 10 M 1.0 x 10 M H
lt OH-
Basic solutions
-8
-14
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Acid / Base Chemistry

• If H 1.0 x 10-9M, will the solution be basic
  or acidic?
• Basic
• Why?
• because the pH 9 and this solution contains less
  H than OH-

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Acid / Base Chemistry

• If OH- 2.63 x 10-4M, will the solution be
  basic or acidic or neutral?
• Why?

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Acid / Base Formulas

• pH -log H
• pOH -log OH-
• pH pOH 14
• H antilog (-pH)
• OH- antilog (-pOH)
• How to use the calculator!!
• Calculate the pH of a solution with H 0.001
  M. Is this acidic, basic, or neutral?

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Acid / Base Formulas

• Calculate the pH of a solution with OH- 7.9 x
  10-3 M. Is this acidic, basic, or neutral?
• Calculate the pH of a solution with H 4.2 x
  10-6 M. Acidic, basic, or neutral?
• What is the OH-?

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Acid / Base Formulas

• A solution with a pH of 9.1 has what H?
• 2nd log 9.1 ENTER
• What is the OH-?
• What is the pOH?

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Scientists Who Define Acids / Bases

• Arrhenius
• Acids Any substance which releases H ion in
  water solution.
• Bases Any substance which releases OH- ion in
  water solution.

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Scientists Who Define Acids / Bases

• Bronsted - Lowry
• Acids Any substance which donates a proton.
• Bases Any substance which accepts a proton.

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Acids, Bases, and Their Conjugates

• Water is amphoteric has basic acidic
  properties.
• Conjugate Acid Substances formed in a reaction
  when a base gains a H
• Conjugate Base Substances formed in a reaction
  when an acid donates H

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Acids, Bases, and Their Conjugates

• NH3 H2O --? NH4 OH-
• HCl H2O ---gt

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Acids, Bases, and Their Conjugates

• CO3-2 H2O ---gt HCO3- OH-
• Ca(OH)2 2HNO3 --gt Ca(NO3)2 2HOH

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Identifying monoprotic, diprotic, and
triprotic monoprotic HCl H
Cl- diprotic H2SO4 H HSO4-1 HSO4-1
H SO4-2 triprotic H3PO4 H
H2PO4-1 H2PO4-1 H HPO4-2 HPO4-2
H PO4-3
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Strengths of Acids and Bases

• Strong acids and bases will completely dissociate
• ex. HCl --gt H Cl-
• The six strong acids - HCl, HBr,
• HI, H2SO4, HNO3, HClO4
• All others are weak.
• Strong Bases Groups I
• and II with OH- except Be

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Strengths of Acids and Bases

• Weak acids and bases slightly dissociate
• ex. HClO lt--gt ClO- H

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Electrolytes and Non-Electrolytes

• Strong Electrolytes
• - Compounds that conduct electricity in aqueous
  solution
• - Substances that completely dissociate
• - Strong acids and bases
• - Soluble salts

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Electrolytes and Non-Electrolytes

• Weak Electrolytes
• - Slight electron conductivity
• - Slight dissociation in aqueous
• - Weak acids and bases
• - Insoluble salts if in molten state

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Electrolytes and Non-Electrolytes

• NonElectrolytes
• - Dont conduct electricity
• - No ions to carry current
• - Organic, molecular

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Examples of Electrolytes and Nonelectrolytes

• H2S03
• weak acid/weak elect.
• CsOH
• strong base/strong elect.
• HCl04
• strong acid/strong elect.
• C6H1206
• nonelectrolyte- covalent, molecular, organic b/c
  carbon

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Examples of Electrolytes and Nonelectrolytes

• Al(OH)3
• weak base/weak electrolyte
• HF
• weak acid/weak electrolyte
• CCl4
• nonelectrolyte- molecular compound
• NaN03
• soluble salt/strong electrolyte
• S03
• acid anhydride/weak electrolyte

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Neutralization Reactions

• General Equation
• Acid Base Salt Water
• HCl NaOH NaCl HOH
• Acid Base Salt Water

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Neutralization Reactions
Titration Analytical method used to determine
the concentration of acids and bases in a
neutralization reaction.
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• Measured volume of an acid or base with unknown
  concentration. Put in Erlenmeyer.
• Add a few drops of indicator to the Ernlenmeyer.
• A measured volume of titrant is delivered into
  the flask through a buret (base or acid)
• Concentration of the titrant is known Standard
  Solution.
• Neutralization occurs when indicator is revealed
  ? End Point
• Equivalence Point
• MOL ACID MOL BASE

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Titration Curve
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Neutralization practice problems

• What volume of calcium hydroxide in a 3.0 M
  solution is needed to neutralize 45.0 mL of 2.6 M
  perchloric acid?

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Neutralization practice problems

• 2. Determine the Ba(OH)2 solution if 300.0 mL
  was titrated to neutrality with 220.5 mL of 6.0 M
  solution of phosphoric acid?

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• Neutralization practice problems
• What volume of calcium hydroxide in a 3.0 M
  solution is needed to neutralize 45.0 mL of 2.6 M
  perchloric acid?
• G 45 mL
• 2.6 M HCl04
• 3.0 M Ca(OH)2
• U ? vol Ca(OH)2

M CR M
vol mol mol vol
Ca(OH)2 HCl04 2 HOH Ca(Cl04)2 0.45 L HCl04 x
2.6 mol HCl04 x 1 mol Ca(OH)2 x 1 L Ca(OH)2
1 L Ca(OH)2 2 mol HCl04 3 mol
Ca(OH)2
2. Determine the Ba(OH)2 solution if 300.0 mL
was titrated to neutrality with
220.5 mL of 6.0 M solution of phosphoric
acid G 220.5 mL 6.0 M H3P04 300.0 mL
Ba(OH)2 U ? M Ba(OH)2
M CR
vol mol mol
3Ba(OH)2 2H3P04 Ba3(P04)2 6HOH 0.2205 L H3P04
x 6.0 mol H3P04 x 3 mol Ba(OH)2 1 L H3P04
2 mol H3P04 1.985 mol Ba(OH)2 1.985
mol Ba(OH)2 0.300L Ba(OH)2
6.62 M Ba(OH)2
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Dissociation examples
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Acid/Base Chemistry

• Hydrogen ion concentration H
• Hydroxide ion concentration OH-
• Pure HOH neutral substance.
• Kw is constant for water. Kw 1E-14 M2

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More Acid/Base Chemistry

• Kw 1x10-7 M1x10-7 M (KwHOH-)
• Most other substances are not neutral
• Indirect relationships between H and OH-
• H will tell us if solution is Acidic or basic.

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Strengths of Acids and Bases

• Strong Acids HCl, HI, HBr, H2SO4, HNO3, HClO4
• Strong Bases Groups I and II with OH- except Be

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• Identifying Electrolytes and Nonelectrolytes
• Strong Electrolytes
• compounds that conduct electricity in aqueous
  solutions
• substance that completely dissociate
• strong acids and bases
• soluble salts
• Weak Electrolytes
• -slight electrical conduct
• -slight dissociation in aqueous solution
• -conducts in molten state
• -weak acids and bases
• -insoluble salts (if in molten state)
• Nonelectrolytes
• -dont conduct electricity
• -no ions to carry current
• -organic, molecular

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Neutralization

• Acid Base gt Salt H2O
• Neutralization is found using titration
• Titration Analytical method used to determine
  the concentration of acids, bases in a
  neutralization reaction.

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Neutralization reactions

• Products always end in a salt and water.
• Acid Base Salt HOH
• Titration- Analytical method used to determin the
  concentration of acids in a neutralization
  reaction.

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Theory