Question

Which of the following compounds is known as Epsom salt?
A.${\text{CaS}}{{\text{O}}_{\text{4}}}{\text{.2}}{{\text{H}}_{\text{2}}}{\text{O}}$
B.${\text{MgS}}{{\text{O}}_{\text{4}}}{\text{.7}}{{\text{H}}_{\text{2}}}{\text{O}}$
C.${\text{FeS}}{{\text{O}}_{\text{4}}}{\text{.7}}{{\text{H}}_{\text{2}}}{\text{O}}$
D.${\text{M}}{{\text{g}}_{\text{3}}}{{\text{(P}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{2}}}$

Answer 1

In this question, we have to identify the chemical formula of Epsom salt. It is also known as heptahydrate sulphate mineral. Epsom salt belongs to the element of group 2. Group 2 elements are Be, Mg, Ca, Sr, Ba and Ra.

Complete step by step answer:
Now, we will discuss all the given options one by one.
First, we have ${\text{CaS}}{{\text{O}}_{\text{4}}}{\text{.2}}{{\text{H}}_{\text{2}}}{\text{O}}$. If we name this compound, it will be calcium sulphate dihydrate, as it contains 2 molecules of water. We know that it is the chemical formula of gypsum.
Second, we have ${\text{MgS}}{{\text{O}}_{\text{4}}}{\text{.7}}{{\text{H}}_{\text{2}}}{\text{O}}$. If we talk about the name of the compound, then it will be magnesium sulphate heptahydrate, as it contains 7 molecules of water. It is also known as Epsom Salt.
Third, we have ${\text{FeS}}{{\text{O}}_{\text{4}}}{\text{.7}}{{\text{H}}_{\text{2}}}{\text{O}}$. It is named as ferrous sulphate heptahydrate, as it also contains 7 molecules of water. It is also known as iron (II) sulphate.
Now, fourth, we have ${\text{M}}{{\text{g}}_{\text{3}}}{{\text{(P}}{{\text{O}}_{\text{4}}}{\text{)}}_{\text{2}}}$. If we talk about the name of the compound, then it will be magnesium phosphate as it contains phosphate ions.
So, in the end we can conclude that the compound named magnesium sulphate heptahydrate is known as Epsom salt.
Hence the correct option is B.

Note:
Epsom salt is known as magnesium sulphate heptahydrate because
-It was discovered from a place named Epsom in Surrey, England.
-It is similar to the table salt due to chemical structure.
-It is quite bitter and obtained from saline rivers of Epsom.