APPENDIX 4.c

USING THE BURET

A vertical stopcock means the buret is closed, and a horizontal stopcock means the buret is open. A helpful tip: the direction of the stopcock follows the direction of the flow.
Rinse the buret with about 10mL of the titrant to prevent the dilution of the titrant. Attach the buret to the stand. Close the stopcock at the bottom of the buret and pour the titrant through a funnel at the mouth of the buret. Slightly lift the funnel to prevent the liquid from overflowing. Fill the buret up to about 5cm above the zero mark.
Open the stopcock to drain some of the liquid (into a beaker). If any air bubble appears, tap the side of the buret until the bubble disappears.
Note that the buret reads in ascending order with the 0.00mL mark at the top. You must be at eye level with the bottom of the meniscus (curved surface of liquid) to read the buret. Reading from above or below the meniscus will result in a parallax error. In order to easily read the meniscus, hold a dark piece of paper behind the buret (or a white piece if using a buret with black marking).
During titration, drain the titrant from the buret into the beaker (containing the reactant) by opening the stopcock. Keep the liquid flowing normally until a few mL from the endpoint. Near the endpoint, allow the liquid to flow a drop at a time. After reaching the endpoint, rinse and dry the tip of the buret.