Simple Removal of Buret Bubbles Frequently, in teaching and research laboratories, we are called upon to perform titrations. Use of a buret, however, is often complicated by the need toremove a bubble that forms at the tip of the buret, just below the stopcock. Traditional instruction has mandated the lossof time and precious standard solution while waiting for the bubble to flow out of the buret. I would like to offer a new method that I have found successful, both as astudent and instructor. With this method the buhble is removed from the huret tip with a minimal amount of time or solution. Pour approximately 1mL of your standard solution into the buret. Open the stopcock, allow the solution ta fill the lower portion of the buret, and close the stopcock. With the stopcock closed, invert the buret ao that the stopcock is at the top while sitting in the buret stand. Rotate the stopcock key 180°. Rotation of the key must be accomplished quickly since there is only a limited supply of solution in the tip of the buret. At this point, check that the bubble bas been removed. Turn the buret right side up, fill with standardsolution, and hegin the titration. If the buret is fairly clean, this method will work the f i t time; however, the method may be repeated aa often as necessary to remove the bubble. David J. Austin Unlverslhl of South Florida Tampa, FL 33620
514
Journal of Chemical Education
