Common Titration Errors to Avoid and How to Correct Them

Overview

• Post By : Kumar Jeetendra


• Source: Microbioz India


• Date: 01 Mar,2024

Titration is a bare-bones technique used in laboratories to evaluate solution concentration through its reaction with another known concentration termed titrant. However, during the process of titration, there are many errors that may occur which can lead to inaccurate results.

Some of the errors are:

Error:

1. Failure to calibrate or maintain Equipment Properly:
2. Poorly calibrated or maintained equipment like burettes or pipettes will give you wrong volume measurements.

Correction:

Incorporate periodic calibration and maintenance for all process equipment as per quality control procedure. Use appropriate calibration solutions to validate the accuracy of burettes and pipettes.

Incomplete Mixing or Reaction:

Error:

Inadequate mixing of solutions or insufficient time for reaction could lead to wrong endpoint detection.

Correction:

During titration, stir or swirl well for proper mixing of solutions. Allow enough time for complete reaction before recording the endpoint at last.

Improper Endpoint Detection:

Error:

Wrong determination of the endpoint leading to under-estimation/over-estimation of the volume used in the titration.

Correction:

Use appropriate indicators or detection methods for accurate end-point determination; observable changes like color change, monitoring pH through a pH meter etc. Perform more than one titration experiment in order to ensure consistency in detecting endpoints.

Titration Error Due to Air Bubbles:

Error:

Presence of air bubbles inside a burette or pipette affects volumetric delivery accuracy.

Correction:

Before carrying out any titration exercise remove all air bubbles from burette and pipette respectively. This may be achieved through priming it’ tapping gently on its side so as bubbles escape’.

Titration Error Due to Parallax:

Error:

Wrong volume readings resulting from an incorrect position from which the meniscus is viewed (parallax error).

Correction:

Ensure reading levels above parallax errors by taking them at your eye level. Properly align the meniscus with the relevant graduation mark on the burette or pipette when recording volume measurements.

Contamination of Solutions:

Error:

Solution contamination can lead to inaccurate results.

Correction:

Be careful when handling solutions in order to avoid contaminations. Make use of clean glassware and do not mix solutions together. Between titrations, rinse glassware well with the appropriate solvent.

Titration Error Due to Temperature Variations:

Error:

Changes in temperature affect rate of reaction and endpoint detection.

Correction:

Solutions’ temperature should be controlled and monitored throughout titration process. In case it is necessary for maintaining uniform temperature conditions, a water bath or temperature-controlled environment may be used.

Over-Titration or Under-Titration :

Error:

Adding too much or too little titrant can lead to inaccurate results.

Correction:

Do a preliminary titration that provides you with an approximate end point before doing the actual experiment. Add more volumes of titrant in such cases so as to achieve end point more accurately.

Being aware of these common errors in titrations and implementing appropriate corrective measures enable scientists to improve on the accuracy and reliability of their titration results. Besides, good lab practices like proper equipment handling, precise technique, regular calibrations are vital for reducing inaccuracies associated with various factors during conduction of titrations experiments as a laboratory method.