Which one is the anhydride of $HClO_4$?

In the following reaction,identify the nature of the product formed by the complete hydrolysis of the underlined atom at $R.T.$:
$\underline{S}F_6 + H_2O \longrightarrow$ No reaction

Which one of the following is a pseudohalide?

In the following reaction,identify the nature of the product formed by the complete hydrolysis of $BrF_5$ at $R.T.$:
$BrF_5 + 3H_2O \longrightarrow HBrO_3 + 5HF$

Phosphorus reacts with $SO_2Cl_2$ to form $PCl_5$ and $X$. At $723 \ K$,$HCl$ gas reacts with $O_2$ in the presence of $CuCl_2$ to form water and $Y$. $Y$ reacts with $X$ in water to form two acids $A$ and $B$. What are $A$ and $B$ respectively?

What is produced when bleaching powder reacts with dilute hydrochloric acid?