Which of the following types of information would most help a chemist identify an unknown substance based on its chemical properties?

• A. Melting and boiling points
• B. Reactivity with acids and bases
• C. Color and physical state
• D. Density and solubility in water

Answer: (B)

Verified step by step guidance

1. Understand that chemical properties describe how a substance interacts with other substances, such as acids, bases, or oxidizers, rather than its physical characteristics.
2. Recognize that melting and boiling points, color, physical state, density, and solubility are physical properties, which describe the substance's appearance or behavior under physical changes but do not reveal how it reacts chemically.
3. Focus on the term 'reactivity with acids and bases' because it directly involves chemical reactions, which are key to identifying substances based on their chemical behavior.
4. Recall that testing reactivity with acids and bases can show whether a substance is acidic, basic, or neutral, and can indicate the presence of certain functional groups or ions, providing valuable chemical identification information.
5. Conclude that among the options, 'reactivity with acids and bases' is the most useful type of information for identifying an unknown substance based on its chemical properties.