© university of south carolina board of trustees calculate the ph in the titration of 100.0 ml of...
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© University of South Carolina Board of Trustees
Calculate the pH in the titration of 100.0 mL of 0.200 M HCl with 0.400 M NaOH after
a) 0.00 mL strong acid problem pH = 0.7b) 25.00 mL strong acid problem pH = 1.1c) 50.00 mL water + spectators pH = 7.0d) 75.00 mL strong base problem pH =12.8
of base are added.
Calculating a Titration Curve:Strong Acid + Strong Base
© University of South Carolina Board of Trustees
Titration of aStrong Acid with Strong Base
pH = 7.0Spectator Ions
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Chapt. 16More Acids and Bases
Sec. 4-5Titration:
Weak Acid + Strong Base ( or weak base + strong acid)
© University of South Carolina Board of Trustees
Titration of aWeak Acid with Strong Base
pH > 7.0
Equivalence Point
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10-5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL c) 10.00 mL d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10−5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL c) 10.00 mL d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10−5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem c) 10.00 mL d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10−5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem pH = 4.74
c) 10.00 mL d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Weak Acid Titration Curve
ab
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10−5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem pH = 4.74
c) 10.00 mL d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10−5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem pH = 4.74
c) 10.00 mL weak base problem d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10−5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem pH = 4.74
c) 10.00 mL weak base problem pH = 8.95
d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Weak Acid Titration Curve
ab
c pH = 8.95
Equivalence Point
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10-5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem pH = 4.74
c) 10.00 mL weak base problem pH = 8.95
d) 15.00 mL
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Chapt. 15Flashback
Sec. 7Mixtures of Acids (Bases)
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If an acid (base) is much weaker (Ka ~100 x smaller) than another acid (base) in the problem, ignore it.
What is the pH of a solution that is 0.100 M in HCl and 0.050 M in HF?
What is the pH of a solution that is 0.100 M in HOCl and 0.050 M in HF?
Mixtures of Acids (Bases)
strong acid
weak acid
Ka = 3.0x10−8 Ka = 3.5x10−4
pKa = 7.52 pKa = 3.46 (reverse)
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10-5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem pH = 4.74
c) 10.00 mL weak base problem pH = 8.95
d) 15.00 mL strong base problem
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Calculate the pH in the titration of 25.00 mL of 0.200 M acetic acid (Ka = 1.8 x10-5) with 0.500 M NaOH after
a) 0.00 mL weak acid problem pH = 2.72
b) 5.00 mL buffer problem pH = 4.74
c) 10.00 mL weak base problem pH = 8.95
d) 15.00 mL strong base problem pH =12.8
of base are added.
Calculating a Titration Curve:Weak Acid + Strong Base
© University of South Carolina Board of Trustees
Titration of aWeak Acid With Strong Base
ab
c
d
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Chapt. 16
Sec. 6Indicators
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pH Indicators
acid solutionunknown concentration
strong base solution known concentration
indicator dye changes color
record volume of base
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pH Indicators• Weak acid/base conjugate pair
• Acid and base forms are different colors
• Small amount used. Little affect on pH.
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Color Changes Near pKIn
HIn + H2O In− + H3O+
Look at [In−]/[HIn] when
pH = pKa - 1 pH = pKapH = pKa + 1
10% colored50% colored90% colored
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Strong-Acid / Strong-Base Titration
Equivalence Point: pH and color change suddenly
color changeKa
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Color Change with 1 Drop
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Want pKa Indicator ~ pH of Equiv. Point
© University of South Carolina Board of Trustees
pH Indicators• Weak acid/base conjugate pair
• Acid and base forms are different colors
• Small amount used. Little affect on pH.
© University of South Carolina Board of Trustees
Titration - Indicator Detection
Equivalence Point: pH and color change suddenly
color changeKa