Question

Theresa creates an experiment where she mixes two red-colored substances together in a container and observes the solution slowly changing from red to blue for the next eight minutes. The solution becomes completely blue after eight minutes.

What does this represent about the type of change happening in the container?

A chemical change started immediately and finished at eight minutes.
A non-chemical change started immediately and finished at eight minutes.
A chemical change occurred at four minutes.
A non-chemical change occurred at four minutes

Answer 1

A chemical change started immediately and finished at eight minutes.

Reason: the gradual color change (red → blue) indicates a chemical reaction producing new substance(s). The reaction begins as soon as the substances are mixed and proceeds over the eight-minute period until the solution is fully changed.