Question

Two different clear liquids are mixed together in a container without changing the pressure or temperature. When the liquids are mixed, bubbles form and rise to the top of the container and a red powdery substance forms which settles to the bottom of the container.

What is the evidence that a chemical change has happened?

Select all that apply.

Responses

color change
color change

new odor produced
new odor produced

formation of a precipitate
formation of a precipitate

generation of a new gas
generation of a new gas

change in temperature

Answer 1

The evidence that a chemical change has happened in the scenario described includes:

1. **Color change** - The formation of a red powdery substance indicates a change in color, which can signify a chemical change.

2. **Formation of a precipitate** - The settling of the red powdery substance at the bottom of the container is evidence of a precipitate forming, indicating a chemical reaction has occurred.

3. **Generation of a new gas** - The formation of bubbles that rise to the top of the container suggests that a gas is being produced, which is also indicative of a chemical change.

While a new odor produced and change in temperature can also be evidence of a chemical change, they are not mentioned as occurring in your specific scenario. Based on the information provided, the relevant evidence for a chemical change is primarily the color change, formation of a precipitate, and generation of a new gas.