The halogen acid used in the preparation of aqua regia is

Select the correct statement.

The reaction of fluorine with dilute $NaOH$ and concentrated $NaOH$ produces,respectively,........

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:

$A$ 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

When fluoride is heated with conc. $H_2SO_4$ and $MnO_2$,the gas evolved is: