© University of South Carolina Board of Trustees pH of a Salt Solution I Determine the pH of a...
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© University of South Carolina Board of Trustees pH of a Salt Solution I Determine the pH of a 0.589 M solution of NaNO 3 .
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Transcript of © University of South Carolina Board of Trustees pH of a Salt Solution I Determine the pH of a...
© University of South Carolina Board of Trustees
pH of a Salt Solution I
Determine the pH of a 0.589 M solution of NaNO3.
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pH of a Salt Solution II
Determine the pH of a 0.589 M solution of Na(CH3COO).
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pH of a Salt Solution II
Determine the pH of a 0.589 M solution of Na(CH3COO).
Determine the pH of a 0.589 M solution of CH3COO− (weak base).
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© University of South Carolina Board of Trustees
Ka Kb = Kw
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Chapt. 15Acids and Bases
Sec. 8Molecular Structure and Acid Strength
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H / A Size Mismatch(up–down periodic table)
H–Br + H2O Br− + H3O+
vs
H–F + H2O F− + H3O+
• HF better e− overlap• Stronger HF bond• Less likely to break• HF less acidic
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A Electronegativity: Primary Atom(left–right periodic table)
HOH + H2O HO− + H3O+
vs
H-F + H2O F− + H3O+
• F more electronegative• F− more stable product• More likely to form• HF more acidic
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A Electronegativity: Secondary Atoms(left–right periodic table)
HOH + H2O H–O− + H3O+
vs
H2SO4 + H2O HSO3O− + H3O+
• SO3 electronegative• help stabilize O−
• More likely to form• H2SO4 more acidic
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Calculate the pH of a solution 0.20 M in NH3 and 0.30 M in NH4Cl (Kb = 1.80 x10−5).
Calculate the pH of a 0.20 M solution of NH3 (Kb = 1.80 x10−5).
Calculate the pH of a 0.30 M solution of NH4Cl (Kb = 1.80 x10-5).
Topic:
Topic:
Topic:
Weak Base
Weak Acid
Weak Base + Conj. AcidWeak Base + Conj. Acid Buffer
NH4Cl NH4+ (Kb = 1.80 x10−5).
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Chapt. 16More Acids and Bases
Sec. 3Buffers
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Definition of Buffers
Buffer Solution:●Weak acid (base) + conj. base (acid)
both present in similar concentrations●Resists change in pH●Simple, general formula
aK 10Base
pH = p logAcid
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Calculate the pH of a solution of 0.20 M NH3 and 0.30 M NH4Cl (Kb = 1.80 x10−5).
pH of a Buffer: Example
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Student Example
Calculate the pH of a buffer that is made from 0.125 mole of HCN (Ka = 4.9 x10−10) and 0.075 mole of NaCN dissolved in 0.5 L of water.
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pH of a Buffer: Formula
aK 10Base
pH = p logAcid
an
Kn
Base10
AcidpH = p log
or
