Answer the question on basis of passage given below:
P block elements are placed in groups 13 to 18 of the periodic table. Their valence shell electronic configuration is \(ns^2\, \ np^{1-6}\). Group 16 of the p-block elements are known as the group of chalcogens having \(ns^2\, \ np^4\) as their general electronic configuration. They exhibit number of oxidation states but the stability of \(-2\) oxidation state decreases down the group. They are sometimes also known as group of chalcogens as the name is derived from the Greek word for brass and points to the association of sulphur and its congeners with copper. Their ionization enthalpy decreases down the group. Oxygen shows anomalous behaviour due to its small size and high electronegativity.
Identify the epsom salt out of the following salts:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → MgSO4·7H2O
Epsom salt is hydrated magnesium sulphate, \( \ce{MgSO4.7H2O} \). It is one of the sulphate minerals in which combined sulphur occurs in nature, along with gypsum and baryte; PbS, ZnS and CuFeS2 are sulphide ores (galena, zinc blende, copper pyrites).
Note: This question is from the pre-rationalised NCERT book (2022-23). The topic is not there in the latest NCERT book (2026-27), and it is also out of the CUET 2026 syllabus.
NCERT (Pre-rationalised edition, 2022-23):
Occurrence – “… Combined sulphur exists primarily as sulphates such as gypsum CaSO4.2H2O, epsom salt MgSO4.7H2O, baryte BaSO4 and sulphides such as galena PbS, zinc blende ZnS, copper pyrites CuFeS2.”