Burettes
TLDRThis instructional video teaches the proper use of a burette in a chemistry lab. It covers setup, cleaning, filling, and accurate volume measurement during titration. The video emphasizes safety, precision, and technique, including how to prevent bubbles and ensure a thorough clean post-use. It assures viewers that with practice, mastering the burette is achievable.
Takeaways
- 🧪 A burette is a laboratory instrument used for titrations and transferring precise volumes of liquid.
- 📏 The burette has a zero graduation at the top and volume increases as you move down, with graduations stopping near the bottom.
- 🚫 The liquid in a burette should never go below the last graduation mark to avoid errors.
- 🔍 The volume of liquid transferred is determined by the difference between the initial and final volumes.
- 🔧 A stopcock at the bottom of the burette controls the amount of liquid delivered and must be handled carefully.
- 🛠️ Proper setup is required for using a burette, including a retort stand, burette clamp, and checking for any damage.
- 💧 The burette must be cleaned thoroughly with deionized water before use to ensure accuracy.
- 🍼 When filling the burette, a funnel is used and care must be taken not to pour solutions above eye level for safety.
- 📊 Initial volume readings should be taken with precision, using a burette card if necessary for clarity.
- 🔄 After use, the burette should be drained, cleaned with tap water and deionized water, and the stopcock should be removed for thorough cleaning.
- 🛑 The stopcock and burette should be stored upside down with the stopcock in a completely vertical position to prevent build-up and allow drainage.
Q & A
What is the primary purpose of a burette?
-A burette is primarily used for titrations and for transferring very accurate and precise volumes of liquid.
How is a burette similar to a Mohr Pipette in appearance?
-A burette looks very similar to a Mohr Pipette, especially at the top where the first graduation is zero.
Why should the liquid in a burette never go below a certain level?
-The liquid should never go below a certain level in a burette because, similar to a Mohr pipette, the graduation stops near the bottom, indicating the lowest safe filling point.
How do you determine the volume of liquid transferred in a burette?
-The volume of liquid transferred in a burette is determined by taking the difference between the final and initial volumes.
What is the function of the stopcock at the bottom of the burette?
-The stopcock at the bottom of the burette allows you to control the amount of liquid delivered. When it's horizontal, the burette is closed, and any variation from this angle causes liquid to leave the burette.
What are the necessary components for setting up a burette properly?
-The necessary components for setting up a burette properly include a retort stand, a burette clamp, and the burette itself. It's important to use the proper clamp to avoid breaking the glassware.
How should you clean a burette before using it?
-To clean a burette, you should remove it from the clamp, close the stopcock, add deionized water to the top, rotate it to cover the inner surface, and then drain most of the water into a waste beaker, leaving a bit to prevent bubbles. This process should be repeated two more times.
Why is it important to leave a small amount of solution in the bottom of the burette tip?
-Leaving a small amount of solution in the bottom of the burette tip helps prevent the formation of bubbles, which could affect the accuracy of the volume measurements.
How should you fill a burette with the solution for titration?
-To fill a burette with the solution, you should lower it to eye level, place a funnel in the top, and pour the solution into the burette, ensuring it drains properly and does not overflow above the zero graduation mark.
What is the correct way to hold and operate a burette during titration?
-During titration, you should hold the stopcock with your non-dominant hand, with the handle between your thumb and index finger and your palm around the back of the burette. This provides support for the stopcock and frees your dominant hand to swirl the receiving vessel.
How do you ensure an accurate initial volume reading when using a burette?
-To ensure an accurate initial volume reading, the liquid level should be lowered below the 0 line. If it's above, you won't be able to get an accurate initial volume reading.
What is the proper procedure for cleaning and storing a burette after use?
-After use, the burette should be drained of the remaining solution through the tip, then rinsed three times with tap water and three times with deionized water. For thorough cleaning, the stopcock can be removed, and all parts should be rinsed. To store, the stopcock should be completely vertical and the burette stored upside down to prevent build-up and allow water to drain.
Outlines
🧪 Introduction to Using a Burette
This paragraph introduces the use of a Burette, emphasizing the importance of watching related videos on Meniscus, Transfer Pipettes, and Mohr Pipettes. It explains that Burettes are used for titrations and precise liquid transfers. The burette's structure is described, including the zero graduation at the top and the stop at the bottom where liquid should not go below. The method of determining liquid volume by taking the difference between initial and final volumes is outlined. Additionally, the paragraph details the setup for using a burette, including the need for a retort stand, clamp, and checking for damage. It also covers the cleaning process of the burette using deionized water and the importance of preventing bubbles by leaving a small amount of liquid in the tip. The paragraph concludes with instructions on adjusting the stopcock and filling the burette with the solution to be used.
📚 Proper Burette Technique and Cleaning
The second paragraph focuses on the proper technique for using a burette, starting with setting up the burette with the tip well below the rim of the flask to prevent solution loss. It describes the positioning of the burette and the use of the stopcock, emphasizing the importance of holding it with the non-dominant hand for control. The paragraph provides a step-by-step guide on recording the initial volume, using a burette card for precise readings, and transferring the solution while swirling the flask. It also explains how to prevent the burette tip from submerging in the solution and how to rinse the flask after transferring the solution. The process of recording the final volume and calculating the transferred volume is detailed. The paragraph concludes with instructions on cleaning the burette after use, including draining, rinsing with tap and deionized water, and disassembling and reassembling the stopcock for thorough cleaning. Finally, it advises on storing the burette upside down with the stopcock open to prevent build-up and allow water to drain.
Mindmap
Keywords
💡Burette
💡Titration
💡Graduation
💡Stopcock
💡Cleaning
💡Meniscus
💡Rinse
💡Initial and Final Volume
💡Erlenmeyer Flask
💡Burette Clamp
💡Deionized Water
Highlights
Introduction to the use of a Burette in chemistry.
Prerequisite knowledge of Meniscus, Transfer Pipettes, and Mohr Pipettes before using a Burette.
Burettes are used for titrations and precise liquid transfers.
The Burette's graduation starts at zero and increases downwards.
Graduation stops near the bottom, indicating the minimum fill level.
Volume of liquid is determined by the difference between final and initial volumes.
Stopcock at the bottom controls liquid delivery.
Proper setup with a retort stand, clamp, and burette is essential.
Inspect the Burette for any damage before use.
Cleaning the Burette with deionized water and a gentle rotation method.
Draining the Burette properly to prevent bubbles.
Adjusting the stopcock for ease of use.
Thorough cleaning of the Burette with deionized water repeated three times.
Filling the Burette with solution using a funnel and careful pouring technique.
Ensuring no overflow when filling the Burette above the zero mark.
Preventing bubble formation by leaving a small amount of solution.
Adjusting the initial volume to be below the 0 mark for accuracy.
Using an Erlenmeyer flask and positioning the Burette correctly for titration.
Holding technique for the Burette for precise control.
Recording the initial volume with precision using a Burette card.
Transferring solution while swirling the flask to ensure thorough mixing.
Final volume recording and calculating the transferred volume.
Cleaning and storing the Burette properly after use.
Removing and cleaning the stopcock for a thorough Burette cleaning.
Storing the Burette upside down with the stopcock open to prevent build-up.
Mastering the use of a Burette through practice in chemistry.
Transcripts
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