$A$ greenish yellow gas reacts with an alkali metal hydroxide to form a halate which can be preferentially used in fire works and safety matches,the gas and halate respectively are

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?

Which of the following elements liberates $O_2$ from water?

Which of the following statements is correct?

Which of the following species gives a diatomic gas with diamagnetic behaviour upon reaction with concentrated $H_2SO_4$?

Which statement is false?