Question

What is blue vitriol?

Answer 1

Definition:
Vitriol is the generic name for a group of chemical compounds made up of sulfates of various metals, originally iron or copper. The color of certain minerals was used to distinguish them, such as blue vitriol for hydrated Copper(II) sulfate.

Structural formula:
1. The structural formula of blue vitriol is $CuS{O}_4,5H_{2}O$ .
2. The anhydrous form is white. When the salt comes in contact with water, it regains its color as per the metal valency, in this case, it turns to blue color.

Final Answer:

Hydrated copper sulfate is blue vitriol.