ASVAB Practice Test

Which of the following actions produce a chemical change?

1. Adding salt to hot water

2. Boiling water

3. Melting ice

4. Shredding paper

The correct answer is: Adding salt to hot water

The action of adding salt to hot water results in a chemical change because it involves the dissolution of salt, which alters its molecular structure and forms a new solution. In this process, the sodium and chloride ions separate and disperse throughout the water, fundamentally changing the properties of the solution compared to the individual components. In contrast, boiling water, melting ice, and shredding paper involve physical changes where the substance retains its chemical identity. Boiling water and melting ice change the state of matter but do not result in new substances being formed. Shredding paper changes the size and shape of the paper but does not alter its chemical composition. Thus, the only action listed that leads to a transformation into a different substance is the addition of salt to hot water.