Final answer:
When a copper rail is dipped in Copper Sulfate solution, a chemical change occurs where Cu2+ ions are reduced to form copper metal, causing the color change and brown layer formation.
Explanation:
When a rail is dipped in a Copper Sulfate solution, the color changes, and the rail is covered with a brown layer. This happens due to a chemical change where Cu2+ ions in the solution are reduced to form copper metal that deposits on the rail, causing the color change.
For instance, when a zinc plate is connected to a copper sulfate solution via a U-tube, reduction and oxidation occur, resulting in the formation of copper metal on one electrode. This is a common phenomenon in redox reactions involving metal ions.
The change in color of the solution and the formation of a new substance on the rail are characteristic indicators of a chemical reaction taking place.
Learn more about Chemical reactions here:
https://brainly.com/question/34137415
