When anhydrous cobalt chloride paper is exposed to water, what color change is observed?

Anhydrous cobalt chloride is a chemical that appears blue when completely dry. When water touches it, the chemical absorbs the water and changes color to pink.

This color change happens because water molecules attach to the cobalt compound. Scientists use this test to check if water is present in unknown substances.

The blue-to-pink change is reversible, meaning heating the pink paper will remove water and turn it blue again. This makes cobalt chloride paper a useful tool for detecting moisture in chemistry labs.