Question

1. four mixtures are made by combining two clear liquids, and observations are made. which mixture demonstrates a chemical change has occurred? a. mixture 1: the combined liquids have a greater mass than either of the starting liquids. b. mixture 2: the liquids, when mixed, produced a solid which settled to the bottom. c. mixture 3: the mixture of the two liquids takes the shape of the container. d. mixture 4: the denser of the two liquids lies below the other, less dense liquid.

Explanation:

• Option A: Mass conservation (mass of mixture = sum of starting masses, so greater mass is incorrect, no chemical change).
• Option B: Producing a solid (precipitate) from two liquids indicates a chemical reaction (new substance formed), so chemical change.
• Option C: Taking container shape is a physical property of liquids (no new substance), physical change.
• Option D: Density - based layering is physical separation (no new substance), physical change.

Answer:

B. Mixture 2: The liquids, when mixed, produced a solid which settled to the bottom.