In volumetric analysis, small mistakes can cause errors in measurement and affect the accuracy of results. These errors can come from different sources:
- Instrumental errors:
- Using burettes, pipettes, or flasks that are not properly calibrated.
- Leaking burette stopcocks or air bubbles in the burette tip.
- Reading the meniscus incorrectly (parallax error).
- Human errors:
- Incorrect measurement of liquids (reading above or below the meniscus).
- Not rinsing apparatus with the correct solution.
- Adding too much or too little titrant near the end point.
- Poor mixing of the solution during titration.
- Chemical errors:
- Using impure reagents or contaminated solutions.
- Using indicators that give a faint or unclear end point.
- Decomposition or evaporation of the solution during storage.
- Environmental errors:
- Temperature changes causing liquid expansion or contraction.
- Presence of dust, gases, or moisture affecting the reaction.
- Calculation errors:
- Wrong recording of burette or pipette readings.
- Mistakes in mathematical calculations or dilution factors.
In short:
Errors in volumetric analysis come from instruments, human handling, chemicals, environment, or calculation mistakes — all of which can affect accuracy and precision of results.