Question

question 5.
mass: 200 g clear mass: 200 g mass: 400 g
the student can conclude that a chemical change occurred because —
a. a solid formed when the two liquids were mixed.
b. there was no temperature change during the experiment.
c. there was no change in mass during the experiment.
d. one substance was denser than the other.

Explanation:

To determine if a chemical change occurred, we analyze each option:

• Option A: Formation of a solid (precipitate) when two liquids mix is a sign of a chemical reaction (new substance formed).
• Option B: No temperature change doesn't indicate a chemical change (physical changes can also have no temp change).
• Option C: Conservation of mass (no mass change) is a principle of both physical and chemical changes, not a specific indicator of chemical change.
• Option D: Density difference is a physical property, not related to chemical change.

Answer:

A. A solid formed when the two liquids were mixed.