The endpoint should be approached slowly, a drop at a time. Use a wash bottle to rinse the tip of the buret and the sides of the flask. Your TA can show you how to deliver a partial drop of solution, when near the endpoint.
A buret is used to deliver solution in precisely-measured, variable volumes. Burets are used primarily for titration, to deliver one reactant until the precise end point of the reaction is reached.
Using a Buret. Depending on the nature of these contaminants, they might have an effect on the concentration of your titrant and the reaction that takes place in your sample. The second and more important reason for rinsing your burette has to do with water. When you're cleaning your glassware, you use water to rinse it off.
If the burette is not completely dry by the time you use it, the remaining traces of water on the inside will make your titrant more dilute and thereby change its concentration.
Consequently, if you don't rinse your burette with titrant and there really is some water remaining inside, the titrant you dispense will be more dilute than it should be.
If there's one place where haste makes waste, it's in the lab. It will only take you a few moments to thoroughly rinse your burette, but that simple act can spare you data anomalies that would force you to repeat a whole experiment — potentially costing hours of your time. Place a "waste" beaker under the buret and allow the titrant to drain through the buret stopcock to rinse the buret tip. Discard the waste rinse solution appropriately. Repeat priming procedure at least two more times to ensure that the solution in the buret is a homogeneous solution that the concentration of the solution is the same throughout the buret.
Discard the rinse solution. Preparing a Buret. To clean the buret, use the following procedure:. Once the buret is clean, clamp it to a stand using a buret clamp. Always make sure the burette is clamped in a perfectly vertical position before taking any readings.
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