A burette is a vital tool in laboratories for precise liquid measurement. To use a burette, set it up securely, draw the liquid accurately, and release it carefully for controlled dispensing. Understanding the correct procedure ensures successful experimentation.
In chemistry labs, the use of a burette is common for titration, a technique to measure volumes precisely. The burette setup involves securing it in a burette clamp, and the proper technique is crucial. Learn how to set up a burette and master its function for effective use in laboratory experiments.
Burets come in a variety of sizes which typically range from 5ml to 100ml. The valve at the end of the glass burette is called a stopcock.
Follow the steps to use the burette:
- Rinse the burette two or three times with the liquid you want to use. Do this by pouring a small amount of liquid into the burette, and rotating the pipette horizontally so that the liquid contacts the entire inner surface of the burette. Let the liquid pass through the stopcock into the waste container.
- Clamp the burette to the burette clamp attached to the ring stand.
- Fill the burette with the liquid you wish to dispense and read the volume. It is not necessary to adjust the liquid level to exactly 0.00 ml, or any other number for that matter. A piece of paper placed on the back of the burette may make it easier to read. Be careful because the numbers on a burette are opposite the numbers on a graduated cylinder.
- Slowly let the liquid drain into the receiving vessel.
- When the appropriate amount of liquid has been delivered, turn off the stopcock and touch the burette to the side of the vessel to remove any partial drops.
- Read the volume of liquid remaining in the burette.
- Calculate the volume of liquid dispensed by subtracting the volume from Step 2 from the volume in Step 6. In this case 23.40 – 21.06 = 2.34 ml of liquid was delivered.
- Drain the burette of any excess liquid and rinse it with water to clean it.