Question

During an investigation, students dropped a tarnished penny into a solution of acetic acid and sodium chloride. Tiny bubbles formed around the penny, and the penny was less tarnished after two minutes of soaking in the acetic acid and sodium chloride solution. The student inferred that a chemical reaction occurred.
What evidence supports the student’s inference?
The penny experienced a color change, and a gas was produced.
The penny experienced a color change, and a precipitate was formed.
The penny experienced a color change and is in a new state of matter.
The penny experienced a color change and produced light.

Answer 1

A. The penny experienced a color change, and a gas was produced.
The penny was less tarnished (color change), and tiny bubbles formed around the penny (due to a gas being produced).