Which of the following best explains why the dissolving of sugar in water is considered a physical change?

• A. No new substances are formed; the sugar molecules remain chemically unchanged.
• B. The sugar undergoes a chemical decomposition.
• C. The process produces carbon dioxide gas.
• D. The sugar reacts with water to form a new compound.

Answer: (A)

Verified step by step guidance

1. Understand the difference between physical and chemical changes: A physical change affects the form or appearance of a substance but does not change its chemical identity, while a chemical change results in the formation of new substances with different chemical properties.
2. Consider what happens when sugar dissolves in water: The sugar molecules disperse throughout the water, but their molecular structure remains intact; no bonds within the sugar molecules are broken or formed.
3. Analyze the options given: Since no new substances are created and the sugar molecules remain chemically unchanged, this aligns with the definition of a physical change.
4. Eliminate options that describe chemical changes: Chemical decomposition, production of carbon dioxide gas, or formation of a new compound all indicate chemical changes, which do not occur when sugar dissolves in water.
5. Conclude that dissolving sugar in water is a physical change because it involves only the physical dispersion of sugar molecules without altering their chemical structure.