A burette is used to deliver solution in precisely measured variable volumes Burettes are used primarily for titration to deliver one reactant until the precise end point of the reaction is reached To fill a burette close the stopcock at the bottom and use a funnel You may need to lift up on the funnel slightly to allow the solution to flow in freely You can also fill a burette using a disposable transfer pipette This works better than a funnel for the small 10 mL burettes Be sure the transfer pipette is dry or conditioned with the titrant so the concentration of solution will not be changed