Blue cobalt(II) chloride paper changes to which color when exposed to water?

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Multiple Choice

Blue cobalt(II) chloride paper changes to which color when exposed to water?

Explanation:
Blue cobalt(II) chloride paper acts as a humidity indicator: its color changes with moisture. In the dry state it looks blue, but when it absorbs water it forms the hydrated compound CoCl2·6H2O, which is pink. This change happens because the hydration alters the electronic environment of the cobalt ion, changing how it absorbs light. So when exposed to water it turns pink; the other colors listed don’t occur for this indicator in normal use.

Blue cobalt(II) chloride paper acts as a humidity indicator: its color changes with moisture. In the dry state it looks blue, but when it absorbs water it forms the hydrated compound CoCl2·6H2O, which is pink. This change happens because the hydration alters the electronic environment of the cobalt ion, changing how it absorbs light. So when exposed to water it turns pink; the other colors listed don’t occur for this indicator in normal use.

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