Potentiometric Titration of Iron with Mohr's Salt

Topics: Titration, Equivalence point, Amperometric titration Pages: 3 (767 words) Published: October 16, 2007
Potentiometric Titrations


The accuracy of a potentiometric analysis is limited by the measurement error for the cell's potential. Several factors contribute to this measurement error, including the contribution to the potential from interfering ions, the finite current drawn through the cell while measuring the potential, differences in the analyte's activity coefficient in the sample and standard solutions, and liquid junction potentials. Errors in accuracy due to interfering ions often can be eliminated by including a separation step before the potentiometric analysis.


The precision of a potentiometric measurement is limited by variations in temperature and the sensitivity of the potentiometer.

Time, cost & equipment

In comparison with competing methods, potentiometry provides a rapid, relatively low-cost means for analyzing samples. Commercial instruments for measuring pH or potential are available in a variety of price ranges and include portable models for use in the field.

Classical Titrations


An important limitation when using a visual indicator is the need to observe the change in color signaling the end point. This may be difficult when the solution is already colored. When working with macro–major and macro–minor samples, acid–base titrations can be accomplished with relative errors of 0.1–0.2%. The principal limitation to accuracy is the difference between the end point and the equivalence point.


The relative precision depends primarily on the precision with which the end point volume can be measured and the precision of the end point signal. The relative precision can be improved by using the largest volume buret that is feasible and ensuring that most of its capacity is used to reach the end point. The precision of the end point signal depends on the method used to locate the end point. With a visual indicator, the precision of the end point signal is usually between ±0.03 mL and...
Continue Reading

Please join StudyMode to read the full document

You May Also Find These Documents Helpful

  • Potentiometric Titration Curves Essay
  • Titration Essay
  • titration Essay
  • Titration Essay
  • Determination of Iron by Redox Titration Essay
  • Essay about Titration
  • Titration Essay
  • Titration Essay

Become a StudyMode Member

Sign Up - It's Free