Which of the following is a chemical property demonstrated by poison gases used in warfare, such as chlorine gas?

• A. They freeze at room temperature, making them easy to store.
• B. They are inert and do not react with any biological tissues.
• C. They are completely odorless and undetectable by humans.
• D. They react with water in the lungs to form corrosive acids, causing severe respiratory damage.

Answer: (D)

Verified step by step guidance

1. Understand the difference between physical and chemical properties: Physical properties describe characteristics that can be observed without changing the substance's identity, such as freezing point or odor. Chemical properties describe how a substance interacts or changes chemically with other substances.
2. Analyze each option to determine if it describes a physical or chemical property. For example, freezing at room temperature is a physical property because it involves a change in state, not a chemical reaction.
3. Recognize that being inert and not reacting with biological tissues means the substance does not undergo chemical changes, so this is not a chemical property demonstrated by poison gases like chlorine.
4. Note that being odorless and undetectable is a physical property related to sensory perception, not a chemical property involving reactions.
5. Identify that reacting with water in the lungs to form corrosive acids involves a chemical reaction, changing the substance and causing damage, which is a clear example of a chemical property.