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    Conductimetric Titrations: Titration of Weak Acid With Weak Base

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    Fred Bamwine
    This document discusses conductimetric titration curves for different types of acid-base titrations. It explains that titration curves depend on the relative strengths of the acids and bases used. The document then provides examples and explanations of the conductimetric titration curves for: 1) titration of a weak acid with a weak base, 2) titration of a strong acid with a weak base, 3) titration of a weak acid with a strong base, and 4) titration of a strong acid with a strong base.

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    Conductimetric Titrations: Titration of Weak Acid With Weak Base

    Uploaded by

    Fred Bamwine
    320 views3 pages
    This document discusses conductimetric titration curves for different types of acid-base titrations. It explains that titration curves depend on the relative strengths of the acids and bases used. The document then provides examples and explanations of the conductimetric titration curves for: 1) titration of a weak acid with a weak base, 2) titration of a strong acid with a weak base, 3) titration of a weak acid with a strong base, and 4) titration of a strong acid with a strong base.

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    Conductimetric Titration

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    This document discusses conductimetric titration curves for different types of acid-base titrations. It explains that titration curves depend on the relative strengths of the acids and bases used. The document then provides examples and explanations of the conductimetric titration curves for: 1) titration of a weak acid with a weak base, 2) titration of a strong acid with a weak base, 3) titration of a weak acid with a strong base, and 4) titration of a strong acid with a strong base.

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    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    320 views3 pages

    Conductimetric Titrations: Titration of Weak Acid With Weak Base

    Uploaded by

    Fred Bamwine
    This document discusses conductimetric titration curves for different types of acid-base titrations. It explains that titration curves depend on the relative strengths of the acids and bases used. The document then provides examples and explanations of the conductimetric titration curves for: 1) titration of a weak acid with a weak base, 2) titration of a strong acid with a weak base, 3) titration of a weak acid with a strong base, and 4) titration of a strong acid with a strong base.

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    © All Rights Reserved
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    Conductimetric titrations

    Variations of conductance may be used to follow the courses of acid-base and precipitation
    reactions. A drawback of the latter is the possible contamination of the electrodes by the
    precipitate formed. A grave disadvantage of any conductance-based titration is its non-
    applicability in the presence of high concentrations of electrolyte species other than those
    required to be determined. This is in contrast to many other electroanalytical techniques where
    such electrolytes not only do not interfere, but offer distinct advantages.
    Conductimetric titration curves for acid-base reactions depend upon the relative strengths of the
    acids and bases used. In order to maintain straight line variations of conductance, it is best to use
    a titrant concentration considerably greater than that of titrant.

    Titration of weak acid with weak base


    In such cases, titration curves of the type shown in the figure above are obtained. Over the region
    AB, corresponding to the initial addition of weak base, the ionization of the weak acid is
    suppressed by the buffer action so that the conductance falls. As the salt is progressively formed,
    the number of ions in solution rises with consequent increase in conductance over BC. In the
    region CD, addition of the weakly ionized base to a solution of its salt causes the conductance to
    almost level off.
    Titration of strong acid by weak base
    The titration plot will take the form shown in the figure above. An initial rapid decline over the
    region AB is due to the replacement of the mobile hydrogen ions by cations of the weak base.
    From B to C the weak base is added in excess to a solution of its salt so that its ionization is
    suppressed. Consequently, the conductance of the excess hydroxyl ions is negligible

    Titration of weak acid by strong base


    The type of titration graph obtained in this case is shown in the figure above. The conductance
    initially rises from A to B as the salt e.g. sodium acetate is formed. Any contribution to the
    overall conductance by that of hydrogen ions is largely suppressed by the buffering action of the
    acetate ion. Beyond the equivalence point, the conductance increases from B to C due to the
    increasing concentration of hydroxyl ions.

    Titration of strong acid by strong base


    The titration graph will have the form shown in the figure above. Rounding of the graph near the
    equivalence point is due to water dissociation. This latter is immaterial since it is only necessary
    to take a number of points well to either side of the equivalence point and to extrapolate the two
    linear segments to the equivalence point. The explanation of the shape of the graph is very
    simple: over the region AB the fast-moving hydrogen ions of the acid are replaced by the more
    slowly moving base cations with a consequent fall in conductance. After all the hydrogen ions
    are removed, the conductance rises between B and C as an excess of hydroxyl ions is added to
    the solution.

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