Potentiometric titration involves determining the potential of a sample based on the volume of the titrant, it has many advantages as well as some disadvantages, let's check them out.
Potentiometric titration is used to determine changes in electrical potential while a neutralizing agent is added to a sample solution. Potentiometric titration is a technique similar to the direct titration of a redox reaction. There are four types of potentiometric titration, such as acid-base titration, redox titration, complexometric titration, and precipitation titration.
This includes determining and recording the cell potential in the unit of millivolt or pH after each addition of titrant. Two types of electrodes are used: an indicator electrode and a reference electrode. Metal ion indicator, glass electrode, calomel electrode, silver chloride electrode and hydrogen electrode are commonly used in potentiometric titration. Various devices such as burette, conical flask, pipette, volumetric flask, funnel, stand, beaker and wash bottle, etc. are needed to perform the titration.
Here are some of the advantages and disadvantages of potentiometric titration.
Advantages of potentiometric titration:
- The main advantage of potentiometric titration is that it is a direct titration in which an indicator is not needed to determine the endpoint or equivalence point of the reaction.
- Potentiometric titration is used as an automated system with greater sample processing capacity which is applied in different fields.
- It can also operate on a sample containing a small amount of analyte whose concentration needs to be determined.
- The advantage of using this valuation method is that it is an inexpensive method.
- The results of this titration are precise and clear, since the equivalence point is not estimated by means of a color indicator.
- This type of titration is functional if the solutions are turbulent, fluorescent and colored in which the end point obtained by the indicator is masked.
- Automated endpoints give accuracy over manual titration.
Disadvantages of potentiometric titration:
- The main disadvantage of potentiometric titrations is that they are very sensitive to pH.
- Potentiometric titration takes longer than indicator titration.
- Errors can occur during the preparation of the solutions or by any contamination.
- If the electrode is exposed to air, the pH reading may be different.
- Need for precisely known solution concentrations.
- We need to calibrate frequently.
- It is very sensitive to changes in ionic strength.
- Compared to manual titration, you need an instrument that has two electrodes, an indicator and a reference electrode.