Question

State the chemical formula of blue vitriol.

Answer 1

Hint: Blue vitriol is an inorganic compound of copper (Cu) element, its chemical name is Cu (II) sulphate pentahydrate. From the chemical name, we can think about the chemical formula of it.

Complete step by step answer:
1.First, let us know about the blue vitriol. It is a copper compound, and known as crystalline copper sulphate.
2.From the other name, we can say that it includes the sulphate ion, and crystalline form depicts the presence of hydrate molecules.
3.Now, we can define the general formula i.e. CuSO$_4$.(H$_2$O)$_x$, and in the general formula, the range of hydrate molecules vary from 0 to 5.
5.As we know the range 5 i.e. pentahydrate is the most common form.
6.The copper sulphate having pentahydrate is encountered with salt, generally blue in colour.
7.So, we can conclude that the blue vitriol has 5 hydrate molecules, as if it will not have the water molecules, it is known as anhydrous copper sulphate.
Thus, the chemical formula of blue vitriol, or Cu (II) sulphate pentahydrate is CuSO$_4$.5H$_2$O.

Additional information: Blue vitriol is a very useful compound. It is used as an analytical reagent, a herbicide, or fungicide, and even as battery electrolytes.

Note: Don’t get confused between the number of hydrate molecules to be considered for the blue vitriol. We need to know the colour of compounds with the varying range, like anhydrous copper sulphate is grey in colour.