Which of the following is the most important step to take every time you are about to heat glassware on a hot plate in the laboratory?

• A. Add cold water to the glassware before placing it on the hot plate.
• B. Inspect the glassware for cracks or chips before heating.
• C. Place the glassware directly on the hot plate without checking its condition.
• D. Seal the glassware tightly with a stopper before heating.

Answer: (B)

Verified step by step guidance

1. Understand the safety concerns when heating glassware: Glassware can break or shatter if it has any structural weaknesses such as cracks or chips, especially when exposed to heat.
2. Recognize that heating damaged glassware can cause sudden breakage, leading to spills, injuries, or accidents in the lab.
3. Identify that the most important precaution is to carefully inspect the glassware for any cracks or chips before applying heat to ensure it is safe to use.
4. Note that adding cold water before heating or sealing the glassware tightly can cause pressure buildup or thermal shock, which are unsafe practices.
5. Conclude that the best practice is to always inspect the glassware for damage before heating to prevent accidents and ensure safe laboratory procedures.