Chlorine acts as a bleaching agent only in the presence of which of the following?

The reaction of $HClO_3$ with $HCl$ gives a paramagnetic gas,which upon reaction with $O_3$ produces

Which of the following is the only existing oxoacid of fluorine?

Which of the following is a pseudohalogen analogue of an interhalogen?

Which of the following pairs shows the highest bond dissociation enthalpy among halogens and the lowest bond dissociation enthalpy among hydrogen halides?

Which of the following represents the correct order of acidic nature?