As the atomic number of halogens increases,the halogens

Hydrolysis of $NCl_3$ gives $NH_3$ and $X$. Which of the following is $X$?

Which statement is false?

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?

Discuss variations in atomic radii and ionization enthalpies in halogens.

Which of the following statements is correct?