Question

Formula of Epsom salt is:
(A) \[{\text{MgC}}{{\text{O}}_{\text{3}}}\]
(B) \[{\text{MgS}}{{\text{O}}_{\text{4}}}\]
(C) \[{\text{MgS}}{{\text{O}}_{\text{4}}}{\text{.7}}{{\text{H}}_{\text{2}}}{\text{O}}\]
(D) \[{\text{MgS}}{{\text{O}}_{\text{4}}}{\text{.6}}{{\text{H}}_{\text{2}}}{\text{O}}\]

Answer 1

Hint: Find out if Epsom salt contains carbonate ion or sulphate ion. Also find out the number of molecules of water of hydration present in the Epsom salt.Magnesium sulphate is an ionic compound that contains magnesium cations and sulphate anions. It has good water solubility. With increase in the temperature, the solubility of magnesium sulphate in water increases.

Complete Step by step answer: Epsom salt is white crystalline salt and is odorless.
It is an inorganic salt as it does not contain carbon-hydrogen bonds. An inorganic salt does not contain carbon-hydrogen bonds. An organic compound contains carbon-hydrogen bonds.
Magnesium carbonate is a salt of weak acid carbonic acid with weak base magnesium hydroxide. Magnesium sulphate is a salt of strong acid sulphuric acid with weak base magnesium hydroxide.
Epsom salt is magnesium sulphate heptahydrate. One molecule of Epsom salt contains seven molecules of water. This water is present as water of hydration. Formula of Epsom salt is \[{\text{MgS}}{{\text{O}}_{\text{4}}}{\text{.7}}{{\text{H}}_{\text{2}}}{\text{O}}\]

Hence, the correct option is the option (C).

Note: Epsom salt can be used for the treatment of body aches. It relieves inflammation and pain. Epsom salt is also used as bath soak as a remedy to sore muscles. You can also take aqueous solution of Epsom salt through mouth as laxative or magnesium supplement.