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A student-quality buret with a PTFE stopcock. These are not Pyrex® glass burets but rather flint glass. The PTFE stopcock plug is ideal in the hands of a student because it is virtually freeze-proof.
Glass Burets with PTFE Stopcock our most popular burette models are glass with Teflon stopcocks
Why do teachers choose these burettes
First nothing beats the chemical resistance of glass you can safely use glass spirits and titrations with strong acids and bases oxidizing agents’ ammonia buffers even halogens dissolved in an organic solvent. Then there's the nature of Teflon it's the world's most slippery substance the main reason old unused buret pile up in the stockroom is because of frozen glass stopcocks that no longer work with Teflon. You never have to worry about frozen or plugged stopcocks again Flynn Scientific has two major lines of glass spirits with Teflon stopcocks and both models come in three convenient sizes our highest quality burets are made of borosilicate glass which ensures the highest possible calibration accuracy due to its low coefficient of expansion for silicate glass spirits. Also come with a replaceable body stopcock and burette tip for long-term value the other model line is made of Flint glass which is perfect for teachers seeking to balance quality convenience and cost no matter which model you choose all of our Burets must-pass product review and QC tests to ensure that your students will always get accurate results you.
How to Titrate Using a Buret
A student's first introduction to quantitative analysis is usually an acid based titration while the analysis itself is rather straightforward. The techniques are a little unique to this method but once learned they're seldom forgotten. Once a burette has been properly filled with the titrant determine the initial volume place the index card marked with the solid line behind and underneath the level of the liquids this will highlight the meniscus making it easier to read record the initial volume of the titrant estimate. The amount of titrant needed and then add several drops of indicator solution to the sample use a burette to deliver a stream titrant within a couple of milliliters of your expected end point you will see the indicator change color when the titrant hits the solution in the flask, but the color change disappears upon stirring for best results you may use a magnetic stirrer but it's not necessary. If a magnetic stirrer is not available, you will need to use a swirling technique approach the endpoint more slowly and watch the color of your flask carefully use the wash bottle to rinse the sides of the flask and the tip of the burette to make sure all titrant is mixed in the flask as you approach the end point you may need to add a partial drop of titrant. You can do this by partially opening the stopcock and rinsing the partial drop into the flask with a wash bottle. When you have reached the end point read the final volume in the burette and record it in your notebook while not difficult learning the proper technique will give the student the confidence he/she needs to focus on the analysis and not the mechanics of the titration.