Manganese dioxide on heating with concentrated hydrochloric acid gives a greenish yellow gas,$X$. With excess of ammonia,$X$ gives $Y$ and $Z$. $Y$ and $Z$ respectively are:

Acid strength of oxyacids of chlorine follows the order:

Consider the following statements about the oxides of halogens:
$A$. At room temperature, $OF_2$ is thermally stable.
$B$. Order of stability of oxides of halogens is $I > Br > Cl$.
$C$. $I_2O_5$ is used in the estimation of $CO$.
$D$. $ClO_2$ is used as a bleaching agent.
The correct statements are:

What are the products formed when chlorine is passed through an aqueous hypo solution?

Mark the element which displaces three halogens from their compounds.

Anhydrous ferric chloride is prepared by