Identify the correct statement(s).
A. Fluorine is a stronger oxidising agent than chlorine.
B. Sulphur in vapour state shows paramagnetic behavior.
C. H2S is more acidic than H2Te.
D. Fluorine form two oxoacids HOF, HOFO.
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A and B only
(A) Fluorine is a stronger oxidising agent than chlorine. — Correct. \( \ce{F2} \) has the higher reduction potential (+2.87 V against +1.36 V for \( \ce{Cl2} \)), owing to its low F–F bond enthalpy and the high hydration enthalpy of \( \ce{F-} \).
(B) Sulphur in vapour state shows paramagnetic behavior. — Correct. At about 1000 K the vapour is mainly \( \ce{S2} \), which, like \( \ce{O2} \), has two unpaired electrons in antibonding π* orbitals.
(C) H2S is more acidic than H2Te. — Incorrect. The H–E bond enthalpy falls from \( \ce{H2S} \) to \( \ce{H2Te} \), so acidic character increases down the group: \( \ce{H2S} \) < \( \ce{H2Se} \) < \( \ce{H2Te} \).
(D) Fluorine form two oxoacids HOF, HOFO. — Incorrect. Because of its small size and high electronegativity, fluorine forms only one oxoacid, HOF.
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):
Chemical Properties – “… The ready acceptance of an electron is the reason for the strong oxidising nature of halogens. F2 is the strongest oxidising halogen and it oxidises other halide ions in solution or even in the solid phase.”
Allotropic Forms of Sulphur – “… At elevated temperatures (~1000 K), S2 is the dominant species and is paramagnetic like O2.”
Reactivity with Hydrogen – “All the elements of Group 16 form hydrides of the type H2E (E = S, Se, Te, Po). Some properties of hydrides are given in Table 7.7. Their acidic character increases from H2O to H2Te.”
Oxoacids of Halogens – “… Due to high electronegativity and small size, fluorine forms only one oxoacid, HOF known as fluoric (I) acid or hypofluorous acid.”