Which of the following occurs during a chemical change?

• A. Change in physical state without altering chemical composition
• B. Formation of new substances with different chemical properties
• C. Separation of mixtures by filtration
• D. Dissolving salt in water

Answer: (B)

Verified step by step guidance

1. Understand that a chemical change involves the formation of new substances with different chemical properties, meaning the original substances undergo a change in their chemical composition.
2. Recognize that a change in physical state (such as melting or boiling) does not alter the chemical composition of a substance, so it is a physical change, not a chemical change.
3. Identify that separation of mixtures by filtration is a physical process used to separate components based on physical properties, without changing their chemical identities.
4. Note that dissolving salt in water is a physical change because the salt dissociates into ions but does not form new substances; the chemical composition of salt remains the same.
5. Conclude that the key characteristic of a chemical change is the formation of new substances with different chemical properties, which distinguishes it from physical changes.