Beakers can not be heated.

Only test tubes can be heated directly in glass instruments, and heating beakers should be padded with asbestos mesh. The bottom of the beaker is large, direct heating with a flame, can only be burned to the local, so that the glass is unevenly heated and cause cracking. In order to prevent cracking, the outer wall of the water to wipe clean before heating. Beaker because of its caliber up and down the same, access to liquids is very convenient, is to do simple chemical reactions the most commonly used reaction containers.

Beakers have a scale on the outside wall, you can estimate the volume of the solution inside. Some beakers will also have a small area on the outside of the wall is white or burlap, in this area can be written with a pencil to describe the name of the contents. If there is no such area on the beaker, the name of the contents can be written on a piece of labeling paper.

Beakers are often used to prepare solutions and as reaction vessels for larger quantities of reagents. During operation, they are often stirred with a glass rod or a magnetic stirrer. The beaker is the most commonly used reaction vessel for simple chemical reactions because its caliber is the same at the top and bottom, and it is very convenient to access the liquid. The volume of the solution inside the beaker can be estimated when there is a scale on the outside of the beaker.

The use of beakers and precautions:

I.

Some beakers also have a small area on the outside wall that is white or burlap, where you can write in pencil to describe the name of the contents. If there is no such area on the beaker, the name of the product can be written on a label and attached to the outside of the beaker for identification purposes. When stirring is required, the reaction is usually stirred with a glass rod.

Second, the use of precautions.

When the solution needs to be moved to other containers, the mouth of the cup can be tilted toward the side with a protruding gap, and the solution can be poured out smoothly. To prevent the solution from flowing down the outside of the cup wall, a glass rod can be used to gently touch the mouth of the cup, then the solution attached to the mouth of the cup can smoothly flow down along the glass rod (diversion).

The beaker should be heated with an asbestos mesh to provide even heat. Can not use the flame to heat the beaker directly, because the bottom of the beaker is large, with the flame directly heated, can only be burned to the local, so that the glass is unevenly heated and cause cracking. When heated, the beaker outer wall must be dry.

When used for dissolution, the amount of liquid to not more than 1/3 of the volume of the beaker is appropriate, and use a glass rod constantly and gently stirred. During dissolution or dilution, do not touch the bottom or wall of the cup when stirring with the glass rod.