Question

chem semester 1 final 2024
which of the following is a chemical change?
○ melting an ice cube
○ dissolving salt in water
○ burning a piece of paper to ash
○ cutting your hair

Explanation:

To determine a chemical change, we check for new substance formation. Melting ice (physical, state change), dissolving salt (physical, solvation), cutting hair (physical, shape change) don't form new substances. Burning paper involves combustion, producing ash, CO₂, etc.—new substances, so it's a chemical change.

Answer:

burning a piece of paper to ash