Test tubes allow us to shrink the size of some of the chemistry we do, so that our chemical waste stream isn't so great. Test tubes can take a stopper, and some have screw caps. If your tube will get hot or if you're concerned about overflow or splashing, a test-tube holder – wire or plastic – will come in handy. If you use a lot of test tubes, you'll need a rack to store them upright, though an empty beaker will hold a few vertically-enough in a pinch. You should be able to find one for your particular use. Test tubes, usually glass, but sometimes plastic, come in a wide array of depths and diameters. In a pinch, an empty beaker will due to balance one in between tasks. Pro tip: If you're using a round-bottom flask on a bench-top, be sure to have a cork ring to set it on, lest it roll away. Round-bottom flasks come in sizes from a few milliliters to a liter or more, and they typically have no volume markings. The near-spherical shape also makes the round-bottom flask strong when subjected to an internal vacuum – it's less likely to implode. Round-bottom flasks are often fitted with glass joints that can be sealed, so that a reaction can be isolated from the outside atmosphere (for example, if you wanted to run a reaction without the presence of oxygen) or so that any evolved gas can be collected. It's shape fits snugly into electric heating mantles, the temperature of which can be controlled more precisely than a burner or hot-plate top. It's especially good for running reactions that require constant heating or boiling. The round-bottom flask is a specialty item of lab glassware that isn't used much, but when it's needed, it's awfully handy.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |