Acid-Base Titrations

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Chapter 17

• Acid-Base Titrations

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Strong Acid- Strong Base H OH- ? H2O K
1/Kw 1 x 1014 Note pH 7 at
equivalence point pH changes rapidly near
equivalence point
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Adding acid to base
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Weak Acid-Strong Base HA OH- ? A- H2O K
1/Kb Running alkali into the acid
Note pH gt 7 at equivalence point pH changes
more slowly near the eq. pt. flat buffer region
leading up to eq. pt.
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Strong Acid- Weak Base H A- ? HA K
1/Ka Running acid into the alkali

• Note
• pH lt 7 at eq. pt.
• pH changes slowly near eq. pt.
• buffer region leading up to eq. pt

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Go to this link and scroll down to explore these
ideas below. Look at the differences between the
different titration curves by turning them on and
off.
http//www.avogadro.co.uk/chemeqm/acidbase/titrati
on/phcurves.htm
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Choice of Indicator HIn ? H In- HIn and In-
have different colors, the color of solution
depends upon the ratio of concentrations Ka
end point occurs when H Ka or
when pH pKa (of the indicator!)
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Choose your indicator to have a pKa near the pH
of the equivalence point of your acid-base
reaction.
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Take the notes quiz here.
https//docs.google.com/spreadsheet/embeddedform?f
ormkeydC1RcUF0dXREVGxPaTVlWmhUb3RqNkE6MQ