Question

Magnesium sulphate crystals are commonly called

Answer 1

Magnesium sulfate crystallizes to give many forms of hydrate where the number of water molecules ranges from 1 to 11. The water molecule can be removed by heating. The magnesium sulphate containing seven water molecules is mostly used as bath salts.

Complete step by step answer:
Magnesium sulphate is salt formed by the reaction between magnesium hydroxide, sulfur dioxide and air. The chemical formula of magnesium sulphate is $MgS{O_4}$ where magnesium is present as cation $M{g^{2 + }}$and sulphate is present as anion $SO_4^{2 - }$.
Magnesium sulphate is used to improve the deficiency of magnesium in soil. Magnesium sulphate is used in formulation of bath salts, Magnesium sulphate is used as the brewing salt is the production of beer. Anhydrous magnesium sulphate is used as a dessicant in organic synthesis as it has greater affinity to water and its compatibility with most of the chemical compounds.
Magnesium sulphate crystallizes to give different hydrates having the formula $MgS{O_4}.n{H_2}O$, where n is the number of water molecules which varies from 1 to 11.
The most common hydrate of magnesium sulphate is heptahydrate. The formula of heptahydrate is $MgS{O_4}.7{H_2}O$. The heptahydrate is known as Epsom salt. Its name is Epsom salt taken from the bitter saline spring in Epsom in Surrey, England. Here the salt is formed from the spring which is present where the porous chalk of the North downs comes in contact with non-porous London clay.
Therefore, the magnesium sulphate is also called Epsom salt.

Note: Double salt of magnesium sulphate is also present like sodium magnesium sulphate and potassium magnesium sulphate.A double salt is a salt that contains more than one cation or more than one anion.