Gold dissolves in aqua regia forming:

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?

Observe the following reaction. This reaction represents:
$4 HCl + O_2 \xrightarrow[723 \ K]{CuCl_2} 2 Cl_2 + 2 H_2 O$

Which one of the following is formed apart from sodium chloride when chlorine reacts with hot concentrated sodium hydroxide?

Which among the following is a powerful bleaching and oxidising agent?

To purify fluorine gas,fumes of $HF$ are removed by