Question

POST-LAB QUESTIONS Explain the effect on your calculated acid concentration if the following errors occurred 1. A student left his or her buret funnel in the buret during the titration. 2. A student started their titration with air bubbles in the buret tip. 3. The dilute HCl was over-diluted in the volumetric flask. 4. The flask that the student added the dilute acid to before the titration was wet. Titration of an unknown Acid

Answer 1

Solution:

1) Decrease in concentration of acid

If burett funnel is not removed, then it may cause error in volume measurement of burret because the drops which are attached to funel increases the volume of burret.

2) The concentration of unknown acid increases

Air bubble in burett causes an indication of addition of higher volume of base, hence the calculated concentration of acid increases.

3) The concentration increases

Overdilluted HCl has causes an error during titration. It causes addition of large amount of base and hence calculated concentration increaeses.

4) Decrease the calculated concentration

A wet flask contains lesser volume of acid, hence less volume of base is required. This will causes decrease the concentration of unknown acid.