17 A student mixes two liquids together and notices that a white solid has formed at the bottom of
the container. What can the student conclude?
8.2(E)
1. A precipitate has formed.
2. A physical change has occurred.
3. A chemical reaction has occurred.
4. A chemical change has occurred.
1 and 2 only
1, 2, and 4 only
1, 3, and 4 only
3 only

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e