 As part of your first lab, you're going to be doing measurements, basic measurements and you're going to be using some basic lab equipment to test the accuracy of certain glassware. So I'm just going to introduce you to certain techniques and to certain, the use of certain instrumentations that will help you in order to do this lab as accurately as possible. So first I'm going to introduce you to how to use a burette. So this is the whole setup of the burette apparatus. This particular cylindrical glass is called a burette. It has a stop cork that will allow liquid to flow in, will basically flow out of the cylindrical glass itself. It is held in place by a burette stand which has a clamp on it, a burette clamp which allows the burette itself to be adjusted up or down depending on your level, your comfort level. So I'm going to start by first showing you how to add a certain amount of volume to this burette and then subsequently use the burette to add a specific volume to another container. So normally we use an Erlenmeyer flask when we are measuring using a burette and the burette is also used for titration. So you will see as time progresses when we do a subsequent titration lab that you're going to be actually using the burette to add a specific volume of liquid to the Erlenmeyer flask and this is going to continue until an endpoint is reached. So this one I'm just going to show you how to add a specific volume of liquid to this Erlenmeyer flask for accurate measurements. So first what we're going to do is to adjust the burette so that I can add my liquid to the burette. So I want to bring it down as much as possible, the burette, so that I can add the liquid using a funnel so that I can accurately, without spilling, add liquid to the burette. And I'm going to fill it to this 20 ml mark. And I'm going to add it gently so that I can minimize spilling off the liquid. So actually because I want 20 ml to be in the burette, I'm going to add it a little bit above the 20 ml mark. And that is so that I can get the most accurate measurement coming out of the burette into my Erlenmeyer flask. So one important thing I wanted to mention about the burette is that unlike some pipettes where the gradation starts from 0 up to 50, the burette actually has increments starting from 0 at the top to 50 at the bottom. The burette would normally, the pipette would normally have gradations from 0 at the bottom to 50 at the top. So I'm going to adjust the burette again so that I can adjust the liquid volume to the desired 20 ml mark. And as a result, take out 10 ml of the liquid, add that to the Erlenmeyer flask. So I gently turn the dial. So another important thing here, the stop cork is in the off position when the dial here is horizontal. If I want the liquid to start flowing out, the dial needs to be not horizontal. And to get the maximum liquid coming out, you can have it being completely vertical. But because I don't want it to flow too much, I'm going to gently turn it until liquid starts flowing out and until it goes to the 20 ml mark. So I got to the 20 ml mark. And the important thing about the burette is that you want to make sure that the liquid fills the tip to the tip of the burette so that the accurate volume of water will be placed in the Erlenmeyer flask. Another thing to note when you're measuring the volume, you want to make sure that your eyes are in line with this curvature formed at the surface of the water. And this curvature is called the meniscus, so you want to make sure that your eyes are in line with the bottom of the meniscus. The bottom should be in line with the volume height that you want to stop at. So I'm going to take out 10 ml, so that means right now I'm at 20 ml, and I'm going to let out fluid that will get me to the 30 ml mark. And again, I do this cautiously so that I won't let out more than I'm supposed to. And I make sure that my eyes are in line with the level of the water, surface of the water. And then when the level gets to the bottom of the meniscus, I'm going to stop. So I delivered 10 ml of liquid from the burette into this 120 ml Erlenmeyer flask. So this is how you can use a burette to transfer a specific volume from the burette to a flask.