Question

What are the differences between Mohr’s salt, and green vitriol?

Answer 1

Hint: Vitriol means a salt that consists of sulphate anion and cation. The cation is mainly iron or copper. Thus, vitriol is nothing of sulphate metals, whereas Mohr’s salt consists of an ammonium group, iron sulphate. Both compounds exist as hydrates but the number of water molecules may be different.

Complete answer:
Iron is a d-block element that is known as a transition metal. It easily undergoes loss of electrons i.e., oxidation. Thus, it is considered a metal. This iron metal combines with ions like sulphate groups and forms different types of chemical compounds.
Some of the chemical compounds that were formed from sulphate and iron metal are Mohr’ salt and green vitriol.

Mohr’s Salt	Green Vitriol
Mohr’ salt has the chemical name of ammonium iron $\left(II\right)$ sulphate.	Green vitriol is nothing but iron $\left(II\right)$ sulphate.
It has the chemical formula of ${\left(N{H}_4\right)}_{2}Fe{\left(S{O}_4\right)}_2{\left(H_{2}O\right)}_6$.	It has the chemical formula of $FeS{O}_4.7H_{2}O$.
It is also known as a salt but not complex compounds, though it consists of a central metal atom along with the groups which act as ligands.	It is formed by the combination of iron metal and sulphate groups. The name vitriol comes from the Latin language which means glass.
This salt exists as a hexahydrate.	This salt mainly exists as a heptahydrate. The powder of this salt will look like pieces of coloured glass.

Note:
Both compounds have the same metal atom which is ferrous and sulphate groups. The number of water molecules is different. Mohr’ salt consists of seven water molecules, whereas green vitriol consists of seven water molecules.