Final answer:
To prevent superheating while heating a test tube over a burner, you can place a stirring rod or a boiling chip in the test tube. These objects promote boiling instead of superheating.
Step-by-step explanation:
When heating a test tube over a burner, it is important to take precautions to prevent superheating. To prevent superheating while heating a test tube over a burner, you can place a stirring rod or a boiling chip in the test tube. These objects promote boiling instead of superheating.
Superheating occurs when a portion of the liquid in the test tube becomes too hot and rapidly converts to gas, which can cause the liquid to be forcefully expelled from the test tube. To prevent superheating, you can place a stirring rod or a boiling chip in the test tube. These objects create surfaces that allow bubbles of vapor to form, promoting boiling instead of superheating.