This is an outline method for carrying out a titration in which an acid is added to an alkali.
Use the pipette and pipette filler to add a measured volume of alkali to a clean conical flask.
Add a few drops of indicator and put the conical flask on a white tile.
Fill the burette with acid and note the starting volume.
Slowly add the acid from the burette to the alkali in the conical flask, swirling to mix.
Stop adding the acid when the end-point is reached (when the indicator first permanently changes colour). Note the final volume reading.
Repeat steps 1 to 5 until you get concordant titres. More accurate results are obtained if acid is added drop by drop near to the end-point.
Record the results in a suitable table. The one here also shows some sample readings.
24.60 cm3 ✔
24.70 cm3 ✔
Readings should be recorded to two decimal places, ending in 0 or 5 (where the liquid level is between two graduations on the burette). The titre is the volume added (the difference between the end and start readings).
Tick (✔) at least two concordant titres. These are titres within 0.20 cm3 (or sometimes 0.10 cm3) of each other.
Calculate the mean titre.
Ignoring the rough run, and run 2 (because it is not concordant):
Mean titre =
= 24.65 cm3
Titration must be used to obtain a solution of a salt and water only, when using an acid and an alkali. This is because there is no insolubleexcess reactant that could be removed by filtration.