Q. Which of the following statements is not true for halogens ?
A) All but fluorine show positive oxidation states.
B) All are oxidizing agents.
C) All form monobasic oxyacids.
D) Chlorine has the highest electron-gain enthalpy.
Explanation
[Solution] Fluorine forms only one oxoacid, HOF (fluoric(I) acid), in which F is assigned an oxidation number of +1, so the claim that fluorine never shows a positive oxidation state is not true. All halogens are oxidising agents, their oxoacids are monobasic, and Cl has the most negative electron gain enthalpy. Answer (1).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.