Which situation describes a chemical property of matter?

• A. Melting point of a metal
• B. Salt dissolving in water
• C. Combustibility of gasoline
• D. Density of a liquid

Answer: (C)

A chemical property of matter is defined as a characteristic that can only be observed during a chemical reaction, which results in the formation of new substances. The combustibility of gasoline exemplifies this type of property because it describes the ability of gasoline to undergo a chemical change when ignited, producing new substances such as carbon dioxide and water.

In contrast, the melting point of a metal, salt dissolving in water, and the density of a liquid are examples of physical properties. These properties describe the state or condition of a substance without altering its chemical composition. For instance, melting point refers to the temperature at which a solid becomes a liquid, and dissolving salt in water is a physical change where the salt remains chemically the same even after it has dissolved. Density, which measures how much mass is contained in a certain volume, is also a physical characteristic that does not involve a transformation of the substance's chemical structure.