Titrations

Burettes are a large source of uncertainty in the experiment. Using the same apparatus, suggest how the procedure could be improved to reduce percentage uncertainty in burette and justify.

Use a more concentrated/ higher volume MHCO₃ or more dilute HCl, so a larger titre/ volume of HCl is needed, which decreases percentage error.

What must you do to obtain an average titre in ax experiment?

Do multiple titrations until you have obtained concordant results

Why is it important to fill the space below the tap in the burette with solution A before beginning an accurate titration?

The space will fill during titration, so if it was included the titre/ volume added would be too high

Why is a conical flask preferred to a beaker?

Less chance of losing liquid when swirling, and liquid won’t splash back up

Why does rinsing the inside of the conical flask with distilled water improve the accuracy of the end point?

Returns reagent on the sides of the flask to the reaction mixture to ensure all the acid and alkali react

Why does the water used for rinsing have no effect on the accuracy of the titre?

it doesn’t change the number of moles of reagent

Why does repeating a titration make the value of the average titre more reliable?

A single titration could be flawed/ anomalous

How does not clearing a large air bubble from below the burette tap have an effect on the value of the first titre?

Value would be higher than the true value