Chapter 13: Titrimetric Methods: Precipitation Titrimetry CHE 321: Quantitative Chemical Analysis Dr. Jerome Williams, Ph.D. Saint Leo University

Overview Titration Basics Primary Standards Standard Solutions Titration Curves

Titration Basics Titrimetry includes a large group of analytical methods based on determining quantity of known concentration required to react completel with analyte. – VolumetricGravimetric – CoulometricRedox – Amperometric Spectrophotometric

Titration Basics Know the following terms. – Standard solution (titrant) – Back titration – Equivalence point – End point – Titration error – Indicators

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Primary Standards A primary standard is an ultrapure compound that serves as the reference material for a titrimetric analysis. Requirements for Primary Standards – High PurityModest Cost – StableAbsence of hydrate water – SolubleLarge Molar Mass

Standard Solutions A standard solution used in titrimetric analysis will be – Stable – React rapidly with analyte – React completely with analyte to see end points – Undergo selective reaction with analyte that can be described by balanced equation

Standard Solutions Overall accuracy of titrimetric analysis limited by accuracy of the concentration of standard solution used in analysis. Two ways to determine concentration – Direct methods – Standardization

Titration Curves Two types of titration curves routinely encountered in titrimetric methods; they are sigmoidal curve and linear segment curve.

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Suggested Problems HW Set 10: 13.1, 13.3, 13.5, 13.7, 13.8, 13.9 HW Set 11: 13.13, 13.15, 13.18, 13.19, 13.24