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.
Match List I with List II
| List I | List II |
| (A) Ammonia | (I) Rotten fish smell |
| (B) Nitric acid | (II) Detection of metal ions |
| (C) Phosphine | (III) Chemiluminescence |
| (D) White phosphorus | (IV) Ostwald process |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A)-(II), (B)-(IV), (C)-(I), (D)-(III)
(A) Ammonia — This matches (II) Detection of metal ions. The lone pair on N lets \( \ce{NH3} \) form complexes with metal ions; with \( \ce{Cu^2+} \) it gives a deep blue complex:
\( \displaystyle \ce{Cu^2+ + 4NH3 -> [Cu(NH3)4]^2+} \)
(B) Nitric acid — This matches (IV) Ostwald process. \( \ce{HNO3} \) is made on a large scale by catalytic oxidation of \( \ce{NH3} \):
\( \displaystyle \ce{4NH3 + 5O2} \xrightarrow[\text{500 K, 9 bar}]{\ce{Pt/Rh}} \ce{4NO + 6H2O} \)
\( \displaystyle \ce{2NO + O2 <=> 2NO2} \)
\( \displaystyle \ce{3NO2 + H2O -> 2HNO3 + NO} \)
(C) Phosphine — This matches (I) Rotten fish smell. \( \ce{PH3} \) is a colourless, highly poisonous gas with a rotten fish smell.
(D) White phosphorus — This matches (III) Chemiluminescence. It glows in the dark because of slow oxidation in air:
\( \displaystyle \ce{P4 + 5O2 -> P4O10} \)
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.