Why is it important to not have any bubbles in the tip of the buret? Bubbles mean the glassware wasn’t cleaned properly The volume measurement will be inaccurate and the actual volume of titrant will be lower than the measured volume. The volume measurement will be inaccurate and the actual volume of titrant will be higher than the measured volume. The presence of bubbles can cause the titrant to splash when dispensing It is OK to have bubbles
The correct answer and explanation is:
Correct Answer:
The volume measurement will be inaccurate and the actual volume of titrant will be lower than the measured volume.
Explanation (300 words):
In titration experiments, accuracy in volume measurement is crucial, and a buret is specifically designed to deliver precise volumes of a liquid reagent known as the titrant. A common issue that compromises the accuracy of the titration is the presence of air bubbles in the buret tip.
When bubbles are present at the tip of the buret, they occupy space that would otherwise be filled with liquid. During titration, as the liquid flows from the buret, the bubble may dislodge and exit the buret along with the liquid. However, the buret still measures this expelled space as if it were entirely filled with liquid. As a result, the reading on the buret will overestimate the volume of titrant actually delivered.
To put it simply: if a bubble was taking up space at the tip, the solution that left the buret was less than the volume shown on the buret. Hence, the actual volume of titrant is lower than the measured value. This leads to inaccurate titration results, potentially affecting the calculation of concentrations, equivalence points, or stoichiometric relationships.
Air bubbles often form due to:
- Improper filling of the buret
- Not priming the tip (filling it fully with liquid before beginning the titration)
- Dirty or improperly rinsed glassware (but this is a separate issue from the bubble problem)
Therefore, before beginning any titration, it is standard lab practice to:
- Fill the buret above the zero mark,
- Open the stopcock to allow some titrant to flow through the tip,
- Ensure no air bubbles remain, especially in the narrow tip section.
Conclusion: Always eliminate bubbles from the buret tip to ensure accurate and reliable volume readings during titration.