Question is based on following passage:
p-block elements are placed in groups 13 to 18 of the periodic table. Group 15 is nitrogen family. Nitrogen makes various compounds like \(NH_3\), \(HNO_3\), \(N_2O\), \(NO_2\) etc. Phosphorus exists in the form of white and red phosphorus. White phosphorus glows in dark. \(PH_3\), gas is used as smoke screen. Group 16 is called oxygen family. Dry air contains 21% \(O_2\) gas by volume. Combined sulphur exists as sulphates such as gypsum, Epsom salt, baryte etc. The allotropic forms of sulphur are Rhombic and monoclinic sulphur. \(S_2\) is paramagnetic like \(O_2\) and it is stable at high temperature. Group 17 is Halogen family. \(F_2\), is highly reactive, \(Cl_2\), is greenish yellow gas. Both \(SO_2\), and \(Cl_2\), are used for bleaching. Group 18 is Noble gas family but some noble gases also form compounds. Complete hydrolysis of \(XeF_6\) gives \(HF\) and \(XeO_3\), as main products.
Sulphate of magnesium, of the following is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Epsom salt
Epsom salt is \( \ce{MgSO4.7H2O} \), the sulphate of magnesium.
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.”