5. Titration with a Burette

General Remarks

As an example of how to use a burette, the movie explains the acid-base titration in "Volumetric Analysis Experiment".
Burettes are graduated cylinders that measure the volume of the drained liquid.
Burettes should not be dried by heating, and thus you may use immediately after rinsing with small amounts of the solution to be measured.
The washing method is also explained in "6. Rinsing of Volumetric Glassware with a Standard Solution".
Because burettes are considerably tall, you may set them on the floor to transfer a titration solution.
Transfer the titration solution into a burette with a funnel and remove the funnel from the burette immediately. Otherwise, the remaining solution on the funnel left on the top of the burette may drop into the burette, which gives a wrong titration result.
The titration solution should be added carefully near the endpoint. For example, add a half drop into the sample solution using a stirring stick. Because you often added an excess amount of the titration solution at the first titration, the first result should be regarded as a preliminary result for the following precise titrations.
Keeping the first titration result in mind, you may add the titration solution quickly until a few milliliters less than the endpoint. After that, you should carefully add the solution to determine the endpoint accurately.

To transfer the titration solution into a burette, close the stopcock at the bottom and use a funnel. Do not forget to remove the funnel after transferring the solution.
Drain a small amount of the solution to expel air bubbles at the tip of the burette. You do not need to adjust the liquid surface to 0.00 mL. Move your eyes to the level of the liquid surface and read the value of the bottom of the meniscus with 1/10 of the smallest scale marked on the burette.

Add a few drops of a phenolphthalein indicator to the sample solution to be titrated.
Shake the vessel to make the sample solution homogenous.
Near the endpoint, a part of the sample solution turns red, which disappears soon by mixing. The disappearance of the color gradually becomes slow.
After the appearance of the transient red color, add the titration solution more carefully drop by drop. At the endpoint, a faint red color does not disappear by mixing.
The titration value is obtained by subtracting the initial reading from the one at the endpoint.
Wash the used burette, keep it upside down on a burette stand, and leave the stopcock open.